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Greening historic districts with solar roofs: an exploration of Western Heights in Los Angeles

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Greening historic districts with solar roofs: an exploration of Western Heights in Los Angeles

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GREENING HISTORIC DISTRICTS WITH SOLAR ROOFS:
AN EXPLORATION OF WESTERN HEIGHTS IN LOS ANGELES
By
Rongzhen Cai

A Thesis Presented to the
FACULTY OF THE USC SCHOOL OF ARCHITECTURE
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the Requirements for the Degree
MASTER OF HERITAGE CONSERVATION
August 2019

Copyright 2019 Rongzhen Cai

ii
Dedication
To my parents, Xiaojie Cai and Jihong Liang, thank you for your supports and sacrifices
for my dreams.

iii
Acknowledgements
The thesis would not have been finished without many people’s support. I would first like
to thank the faculty in the USC Heritage Conservation program. Thank you for leading me into
the world of heritage conservation. This is one of the best experiences of my life.
I would like to thank my thesis committee. Thank you to my committee chair, Trudi
Sandmeier, for inspiring me to the research topic, guiding me through the exploration, and
helping me to pull all pieces together. Thank you to Peyton Hall and John Lesak for being on my
committee and providing thoughtful comments. They encourage me to go deeper and make the
thesis stronger.
I would also like to express my gratitude to my family and friends for providing
continuous encouragement. Thank you to my parents, Xiaojie and Jihong, for supporting me to
pursue my graduate degree, and thanks Chunyu, for always being by my side.

iv
Table of Contents
Dedication ...................................................................................................................................... ii
Acknowledgements ...................................................................................................................... iii
List of Tables ................................................................................................................................ vi
List of Figures .............................................................................................................................. vii
Abstract ......................................................................................................................................... ix
Introduction ................................................................................................................................... 1
Chapter 1: Sustainable Conservation and Solar Energy .......................................................... 5
Sustainable Conservation and Energy Efficiency ....................................................................... 5
Implementing Solar Energy in Historic Properties ..................................................................... 7
Considerations and Challenges ................................................................................................. 10
Chapter 2: Understanding the Technology .............................................................................. 14
The Solar Energy System.......................................................................................................... 14
Evolving Technology – Solar Roof .......................................................................................... 15
Other Solar Technologies ......................................................................................................... 19
Chapter 3: Framework of Implementing Solar Energy in Historic Districts, Los Angeles . 20
The History of Solar Energy in California ................................................................................ 20
Solar Rights Act and Historic Resources .................................................................................. 23
Summary of Solar Energy Legislation and Milestones ............................................................ 26
Evaluation Tool: L.A. County Solar Map ................................................................................. 27
Chapter 4: A Good Candidate – Western Heights HPOZ, Los Angeles................................ 29
A Brief History of Western Heights HPOZ .............................................................................. 29
Architectural Styles and Roof Features of the Western Heights HPOZ ................................... 33
Rehabilitation Guideline ........................................................................................................... 37
Being a Good Candidate of Implementing Solar Roofs ........................................................... 39
Chapter 5: Adopting Solar Roofs in the Western Heights HPOZ ......................................... 43
Research Methods ..................................................................................................................... 43
Field Survey .............................................................................................................................. 44
Analysis and Comparison ......................................................................................................... 48
Impacts Study............................................................................................................................ 53
Conclusion ................................................................................................................................... 57
Bibliography ................................................................................................................................ 60
Appendices ................................................................................................................................... 64

v
Appendix A: Incorporating Solar Panels in a Rehabilitation Project .......................................... 64
Appendix B: Apollo Tile II Solar Roofing System – CertainTeed Solar ....................................... 67
Appendix C: Sunslate6 Installation Manual – Aesthetic Green Power ........................................ 70
Appendix D: An Example of the Solar Roof Report ...................................................................... 86
Appendix E: Western Heights HPOZ Preservation Plan ............................................................. 89

vi
List of Tables
Table 3.1 Summary of solar energy legislation and milestones ................................................... 26
Table 4.1 Architectural features of the Western Heights HPOZ .................................................. 35
Table 5.1 Example of field survey spreadsheet ............................................................................ 45
Table 5.2 Calculation of solar roofs energy efficiency ................................................................. 51

vii
List of Figures
Fig 1.1 Sustainability Guideline for solar panels ............................................................................ 8
Fig 1.2 Solar roof installation examples ....................................................................................... 12
Fig 2.1 Solar panel system ............................................................................................................ 15
Fig 2.2 Solar roof tiles working principle ..................................................................................... 16
Fig 2.3 Solar roof installation on some residential houses ........................................................... 18
Fig 2.4 New England Wildlife Center .......................................................................................... 18
Fig 3.1 GIS map of U.S. solar resources....................................................................................... 20
Fig 3.2 L.A. County Solar Map .................................................................................................... 28
Fig 4.1 Historic Western Heights.................................................................................................. 30
Fig 4.2 HPOZ survey map of Western Heights ............................................................................ 31
Fig 4.3 Historic Sanborn Map 1921 of Western Heights .............................................................. 31
Fig 4.4 Western Heights HPOZ ................................................................................................... 32
Fig 4.5 Buildings in various architectural styles ........................................................................... 32
Fig 4.6 Properties with small flags ............................................................................................... 33
Fig 4.7 Contributing properties in bad condition .......................................................................... 33
Fig 4.8 Satellite view of the Western Heights HPOZ ................................................................... 40
Fig 4.9 Diagram of roof forms for solar roofs .............................................................................. 41
Fig 4.10 Solar map of a portion of the Western Heights HPOZ ................................................... 41
Fig 4.11 Roof materials compatible with solar roofs .................................................................... 42
Fig 5.1 Flowchart of research methods ......................................................................................... 44
Fig 5.2 Contributing properties with solar panels 1 ...................................................................... 45
Fig 5.3 Contributing properties with solar panels 2 ...................................................................... 46
Fig 5.4 Non-contributing properties with solar panels ................................................................. 46
Fig 5.5 Non-suitable roof colors for solar roofs ........................................................................... 47

viii
Fig 5.6 Map of candidate properties ............................................................................................. 48
Fig 5.7 Solar Map of candidate properties .................................................................................... 49
Fig 5.8 Solar panels installation illustration 1 .............................................................................. 54
Fig 5.9 Solar panels installation illustration 2 .............................................................................. 54
Fig 5.10 Rendering of solar roofs installation .............................................................................. 56

ix
Abstract
One of the most significant methods for improving an historic building’s energy
performance is to implement an on-site renewable energy system like solar energy. Although
solar panels are commonly used successfully in dwellings, their use on historic properties and the
potential impact to historic character remains controversial. Recently, a new improvement has
been invented based on solar panel technology. Solar roofing systems can be produced with
small tiles matching both the conventional roofing color and form. With this technology, it will
be possible to integrate a solar energy system and a historic property without compromising its
distinctive character. This thesis explores the possibility of adopting solar roofs in an historic
district and analyzing the potential outcomes. The Western Heights Historic Preservation Overlay
Zone in Los Angeles was selected as an appropriate neighborhood for installing solar roofs. The
evaluation includes candidate identification and energy efficiency calculation, as well as a
comparison between solar panels and solar roofs. Ultimately, this thesis explores the possibility
of using solar roofs on historic properties to focus attention on this promising blend of
sustainable design and heritage conservation.

1
Introduction
For too long, we have been building our world with the assumption that natural resources
are inexhaustible. Especially since the debut of the International Style of architecture, our
building methods changed drastically with the new formulations of comfort standards and new
materials.
1
New technology enabled us to build the same house anywhere and the same interior
conditions could be achieved regardless of the location. Heating and air conditioning enabled the
buildings to overcome the weather through high consumption of energy. The Oil Embargo in
1973 not only awakened public awareness of energy limits, but also encouraged the development
of the sustainability movement, including the adoption of solar energy in buildings.
2
Today, the
world is experiencing ever more extreme weather-related disasters each year. Climate change
indicates that human activity is having great impact on nature, destroying the planet’s
ecosystems and resources. “Climate change” is no longer an exaggeration to scare people, it is
real and requires all human beings’ efforts to handle for a sustainable future.
In response to climate change, heritage conservation is finding ways to mitigate climate
change by upgrading building systems, technology, and rehabilitation methods. The advocates of
heritage conservation think about the long-term survivability of existing buildings regarding
maintenance, improvement, and innovation for future generations.
3
The concept of embodied
energy, first raised by Richard G. Stein in 1970s and later adopted by the Advisory Council on
Historic Preservation (ACHP), implies that an energy crisis and an architectural crisis are
interwoven with each other since buildings are responsible for over forty percent of the energy
used in the United States.
4
This concept further reinforces the importance of heritage
conservation in sustainable development. Vernacular houses that function in harmony with the
environment are early energy efficient models by making simple, yet efficient use of natural
resources like solar and wind. Although many other older homes are not performing efficiently

1
Richard G. Stein, Architecture and Energy (New York: Anchor Press/Doubleday, Garden City, 1977), 2.
2
Amalia Leifeste, Barry L. Stiefel, Sustainable heritage: Merging Environmental Conservation and Historic
Preservation (New York and London: Routledge, 2018), 89.
3
The terms of heritage conservation, historic conservation, and conservation will be mainly used in this thesis. The
term of historic preservation will only be used when it comes to official documents such as historic preservation
ordinance, historic preservation boards, etc. Heritage conservation/historic conservation deals with both tangible and
intangible heritage. It is about managing change of a place. Also, the term of sustainable conservation in this thesis
means conserving heritage in a sustainable way such as making improvement, renovation, rehabilitation of existing
buildings for saving energy in a long term.
4
Richard G. Stein, Architecture and Energy, 1.

2
today, they contain embodied energy that deserves to be recognized. Meanwhile, technological
advancement provides more possibility for sustainable heritage and building conservation, such
as improving the building envelope and adopting renewable energy in historic properties.
Today, sustainable conservation is supported by various preservation boards throughout
the United States. Many design guidelines for historic properties encourage owners to adopt
renewable energy in their house. Compared to other renewable resources like wind or geothermal
energy, solar energy is the most common type of energy using in dwellings due to its
accessibility in the most regions. According to a study published in Environmental Science and
Technology in 2008, eighty-nine percent of air emissions associated with electricity generation
could be prevented if we used solar photovoltaic (PV) energy to displace conventional fossil-
fuel-based electricity.
5
Since 2010, the National Park Service has published a series of guidelines
for installing solar panels and meeting the Secretary of the Interior’s Standards for
Rehabilitation. The Illustrated Guidelines on Sustainability for Rehabilitating Historic Buildings
also includes a section on installing solar technology. Yet, there are still questions about the
adoption of solar energy in historic properties. Mostly, concerns remain in the aesthetic issues
that brought by solar panels towards historic roofs. The discord between solar panels and historic
roofing materials supposes that solar installations will lead to degradation of the visual integrity.
Moreover, in states like California, the state Solar Rights Acts discourages discretionary review
of solar installations, exempting solar panel installations from historic preservation design
reviews. These exemptions further strengthen the threats of solar panel installation leading to
visual disharmony in historic properties.
While the advocates of heritage conservation are seeking alternative methods like
Community Solar, the evolving technology at the same time provides more possibilities for
sustainable conservation.
6
Recently, solar roofs systems have been introduced to the market.
Unlike solar panels, the solar roofs are also called “building-integrated photovoltaic.” The
smaller tiles both produce electricity and provide a weather barrier / functional roof. The colors
of solar roofs can also be compatible with historic roof colors and thus reduce the loss of visual

5
Jean Carroon, Sustainable Preservation: Greening Existing Buildings, (New Jersey: John Wiley & Sons, Inc.,
2010), 180.
6
“Community Solar” is to install solar panels either on rural sites or on some of the many commercial roofs hat
exists in a community.

3
character. To date, there is limited research on the adoption of solar roofs, let alone experiments
on historic properties.
While the energy production of an individual solar roof tile could never compare to a
solar panel’s, the result might turn out differently with a total energy calculation in a whole
historic district. Even though solar panels are more efficient, they should not be used in a place
on a historic building that can be viewed from the street. Less intrusive solar roofs might be able
to be installed on a larger roof area in a historic district, increasing the amount of energy it
provides. The aim of this thesis is to explore the possibility of adopting solar roofs in a historic
district. To conduct research on adopting solar roofs in a historic district, there are four aspects to
consider: the identification of potential candidates, a calculation of the energy efficiency of solar
roofs, a comparison between the energy production of solar roofs and solar panels, and the
potential visual outcome after installation. The Western Heights Historic Preservation Overlay
Zone (HPOZ) in Los Angeles was selected to conduct this experiment for its ideal conditions to
install solar roofs. Fifty-nine of 127 contributing properties have been identified as candidates for
their suitable solar orientation and roof styles, as well as roof colors. With this neighborhood,
this thesis is able to provide practical information of adopting solar roofs in a historic district.
The thesis consists of five chapters. Chapter 1 introduces the broad context of sustainable
conservation and its relationship towards solar energy around the United States. Although many
preservation design guidelines encourage the adoption of solar energy, the use of solar energy is
still restricted in many aspects for conserving historic character. Chapter 2 introduces the
working principles of solar energy systems on dwellings and the development of solar roofs.
These products may provide new methods for both conserving historic integrity and adopting
renewable energy at the same time. Yet, there are limited cases of using solar roofs on a historic
property. Chapter 3 summarizes the overall framework of adopting solar energy in a historic
district of the City of Los Angeles, since the thesis has chosen a historic district in Los Angeles
as the study plot for adopting solar roofs. A brief development of solar energy in Los Angeles is
illustrated with the framework of policies, incentives, and design guidelines of using solar energy
in a historic district. The chapter also introduces an analysis tool for using solar resources in the
county, the L.A. County Solar Map. Chapter 4 presents an overview of the Western Heights
Historic Preservation Overlay Zone (HPOZ) in Los Angeles: the location, history, architectural
features, and the reasons for choosing this historic district to conduct the study. After

4
demonstrating the context of the Western Heights HPOZ, an analysis and calculation of adapting
solar roofs in this district are given in Chapter 5. A field survey was conducted for candidates’
data collection and spreadsheets were used for comparison with data from the L.A. County Solar
Map, showing the potential outcomes of adopting solar roofs in a historic district.
Generally, the thesis provides a reference for adopting solar roofs in a historic district.
Although it is narrow in scale, it will inspire further research on using other new technology to
make historic buildings greener. There are more ways to make our building green. While
heritage conservation is already inherently sustainable, all people in this field should keep on
working on practical methods with evolving technology. Methods should ensure the
improvement of building performance without compromising or damaging historic character.
As Jean Carroon mentions in her book Sustainable Preservation: Greening Existing
Buildings, we must reshape our culture to become one of reuse, repair, and renewal that is
respectful of existing resources, including buildings.
7
Evolving energy technology like solar
roofs provides a better way for heritage conservation to rehabilitate our existing built
environment.

7
Jean Carroon, Sustainable Preservation: Greening Existing Buildings, 18.

5
Chapter 1: Sustainable Conservation and Solar Energy
“In order to reasonably hope for the survival of our species, with some continuity with
the meaningful traditions of our past and retention of the biodiversity of the Earth, we must see
heritage preservation and sustainable design integrated together."
-- Amalia Leifeste and Barry L. Stiefel, Sustainable Heritage: Merging Environmental
Conservation and Historic Preservation
Sustainable Conservation and Energy Efficiency
In the 1960s, heritage conservation in the United States was rarely connected to
environmental issues. Historic preservation was once defined as the movement to only take care
of existing buildings, landscapes, and other artifacts due to their architectural significance.
8
Yet,
the limited natural resources and consistent climate change challenge us to conserve more even
in our built environment.
In the 1970s, Richard G. Stein had already started to explore the energy consumption of
buildings:
Energy is consumed in the complete process of making and assembling buildings’
components, to operate the various systems during the useful life of buildings, in
the transportation systems predetermined by decisions on how buildings are
grouped together, and to demolish buildings or to dismantle the shells of buildings
that have been destroyed in other ways.
9

The concept of embodied energy was further emphasized by the 1976 report entitled
Energy Use for Building Construction by the Advisory Council on Historic Preservation
(ACHP).
10
Embodied energy is the description of energy used directly and indirectly in raw
material acquisition, production of materials, transportation, and the assemblage of those
materials into a building.
11
According to U.S. Energy Information Administration and the U.S.
Department of Energy, buildings account for up to forty-one percent of the nation’s energy
consumption, seventy-two percent of its electricity consumption, thirty-eight percent of its

8
Amalia Leifeste, Barry L. Stiefel, Sustainable heritage: Merging Environmental Conservation and Historic
Preservation (New York and London: Routledge, 2018), 1.
9
Richard G. Stein, Architecture and Energy (New York: Anchor Press/Doubleday, Garden City, 1977), 5.
10
Mike Jackson, “Embodied Energy and Historic Preservation: A Needed Reassessment,” APT Bulletin, Vol. 36,
Not. 4 (2005): 47-49.
11
Jean Carroon, Sustainable Preservation: Greening Existing Buildings, (New Jersey: John Wiley & Sons, Inc.,
2010), 7.

6
carbon dioxide emissions, and approximately fifty percent of all raw materials transformed from
nature.
12
Energy from nature is embodied in our construction and thus demolition of buildings
generates a of waste of energy.
In 2007, Carl Elefante’s essay “The Greenest Buildings is…One That is Already Built” in
the Forum Journal of the National Trust for Historic Preservation, mentioned that
Taking into account the massive investment of materials and energy in existing
buildings, it is both obvious and profound that extending the useful service of life
of the building stock is common sense, good business, and sound resource
management… the Greenest Building is the one that’s already built.
13

Although there is growing process to use sustainable design in new buildings like
vegetative roofs or renewable energy sources, sustainability is still far from fully realized.
14
It is
certainly impossible to rebuild all existing buildings into green structures with even more energy
consumption. The effective way to achieve sustainability is not only about building new green
buildings but also about converting our great number of existing buildings into sustainable
buildings. To achieve this goal, an intersection between sustainable design and conservation
should be studied.
According to Carl Elefante, conservation should accept the need to improve the energy
performance of the existing building stock, to improve building envelope performance, to
upgrade the effectiveness of all energy consuming systems, and to convert to renewable energy
sources both on and off site.
15
New standards for sustainable construction, such as the Leadership
in Energy and Environmental Design (LEED) certification program and analytical tools like
energy audits and life cycle assessments (LCAs) enable builders to conduct an assessment of
energy saving options in both new and existing construction.
16

12
Stephanie Meeks and Kevin C. Murphy, the Past and Future City: How Historic Preservation is Reviving
America’s Communities (Washington, Covelo, London: Island Press, 2016), 238; Erica Avrami, “Sustainability and
the Built Environment: Forging a Role for Heritage Conservation,” Sustainability & Heritage (Spring 2011), The
Getty Conservation Institute:
http://www.getty.edu/conservation/publications_resources/newsletters/26_1/feature.html.
13
Carl Elefante, “The Greenest Building Is…One That is Already Built,” Forum Journal, Volume 21, No.4,
(Summer 2007), The Journal of the National Trust for Historic Preservation: 32.
14
Elefante, “The Greenest Building,” 26.
15
Elefante, “The Greenest Building,” 35.
16
LEED, or Leadership in Energy and Environmental Design, is the most widely used green rating system in the
world. It provides a framework to create healthy, highly efficient and cost-saving green buildings. The certification
of LEED is a globally recognized symbol of sustainability achievement; “LEED is green building,”
https://new.usgbc.org/leed; Avrami, “Sustainability and the Built Environment,” 2.

7
To date, besides preserving significance, heritage conservation is already practicing
sustainability. The term – “sustainable conservation” merges green building design and heritage
conservation together. It adopts methods like rehabilitation, improvement for existing building
systems, and reusing building fabric to extend the service life period of buildings. Sustainable
conservation is, in part, making use of historic properties’ significance to gather people together
to save buildings and save energy. While many modern buildings have been designed to use
renewable energy like wind or sun, historic sites are also increasingly adopting this technology
too.
Implementing Solar Energy in Historic Properties
Solar energy is one of the most sufficient resources on earth. The development of solar
energy in the United States followed the 1973 oil crisis. In 1974 the first of several solar energy
bills went into law and the Congress responded by enacting the Solar Energy Research,
Development and Demonstration Act of 1974. In 1976, Michael Holtz wrote solar design guides
-- Solar Dwelling Design Concepts.
17
Although solar technologies have already been around for
several centuries, this legislation and guidance encouraged the development of solar energy
usage on dwellings.
18

To use the solar collectors in historic buildings successfully without damaging historic
resources, the Secretary of the Interior’s Standards for Rehabilitation provide a framework for
alteration of historic resources while retaining the historic character of the building site, and
district. Specifically, two standards are pertinent to solar energy projects:
19

Standard 2: The historic character of a property will be retained and preserved.
Standard 9: New additions, exterior alterations, or related new construction will
not destroy historic materials, features, and spatial relationships that characterize
the property. The new work will be differentiated from the old and will be

17
Phillip James Tabb, “1970s: Solar Architecture” in The Greening of Architecture: A Critical History and Survey
of Contemporary Sustainable Architecture and Urban Design, edited by Phillip James Tabb and A. Senem Deviren,
(Ashgate Publishing, 2016), 49.
18
Tabb, “1970s: Solar Architecture,” 52: in the 18
th
century Horace de Saussure successfully constructed a
rectangular box out of half-inch pine and generated heat.
19
U.S. Department of Energy, North Carolina Solar Center, National Trust for Historic Preservation, Installing
Solar Panels on Historic Buildings: A Survey of the Regulatory Environment, prepared in August 2012: 10,
https://www.solsmart.org/media/installing-solar-panels-on-historic-buildings_0812.pdf.

8
compatible with the historic materials, features, size and proportion, and massing
to protect the integrity of the property and its environment.
20

The Guidelines on Sustainability further supplement the existing Standards for
Rehabilitation with recommendations for installing sustainable technology systems in a historic
building while still conserving the historic character. (Figure 1.1)

Fig 1.1: The sustainability guideline for solar panels. Source: The Secretary of the Interior’s Standards for
Rehabilitation & Illustrated Guidelines on Sustainability for Rehabilitating Historic Buildings, U.S. Department of
the Interior, National Park Service, Technical Preservation Services,
(http://www.ohp.parks.ca.gov/pages/1054/files/NPS%20sustainability-guidelines.pdf).
In 2009, The National Park Service also created another guideline: Incorporating Solar
Panels in a Rehabilitation Project. This provides guidance for the installation of solar panels in
historic properties while meeting the Secretary of the Interior’s Standards for Rehabilitation. The
goal is to minimize visibility to avoid diminishing the historic character of the building:
21

20
“Secretary of the Interior’s Standards for Rehabilitation,” Technical Preservation Service, National Park Service,
https://www.nps.gov/tps/standards/rehabilitation.htm.
21
Jenny Parker, “ITS Number 52 Interpreting the Secretary of the Interior’s Standards for Rehabilitation:
Incorporating Solar Panels in a Rehabilitation Project,” ITS Number 52 (August 2009), Technical Preservation
Services, National Park Service.

9
Therefore, the installation of solar panels should conform to guidance regarding
rooftop additions, i.e. that they be minimally visible, to avoid altering the historic
character of the building. Historic buildings with a flat roof or parapet can usually
accommodate solar panels because the panels will be hidden, while properties
with a hipped or gabled roof are generally not good candidates for a rooftop solar
installation. Solar panels on historic buildings should not be visible from the
public right of way such as nearby streets, sidewalks or other public spaces.
In circumstances where solar collectors are not placed on rooftops, they should
only be positioned in limited or no-visibility locations in secondary areas of the
property...For some historic buildings, it may not be possible to incorporate solar
panels and meet the Secretary of the Interior’s Standards for Rehabilitation.
22

There are three listed circumstances of the installation of solar panels on historic
buildings: installation on a flat roof, installation on the rear slope roof, and installation on the
rear yard of the property. In the meanwhile, more examples are listed on the Technical
Preservation Service website such as installation on the pole-mounted array, on a low-slope roof,
on a cross gable, etc. (Appendix A)
In 2011, the National Renewable Energy Laboratory (NREL) published “Implementing
Solar PV Projects on Historic Buildings and in Historic Districts” which provides guidance
regarding the usage of solar technologies within historic properties. In addition to introducing
historic preservation regulations as well as incentives, and an overview of solar photovoltaic (PV)
technology, the document provides a five-step process for implementation. It also demonstrates
the intersection of heritage conservation and solar disciplines in order to meet the various criteria
such as the Secretary’s Standards for Rehabilitation and local design guidelines. According to the
NREL, Rehabilitation is the most appropriate treatment approach for integrating solar projects.
23

Local solar panel guidelines and incentives throughout the United States are provided in the
NREL guideline to help people to produce solar projects on historic properties successfully.
Also, the NREL presents a process for implementing a solar energy project. To conduct a
solar PV project, the first step is to identify potential project and stakeholders for different levels.
For example, owners need to find out the public agencies responsible for administering the

22
Ibid.
23
According to “the Secretary of the Interior’s Standards for Treatment of Historic Properties with Guidelines,”
there are four treatments: Preserving, Rehabilitating, Restoring and Reconstructing. A treatment for a historic
building requires careful decision-making about a building’s historical significance as well as other considerations
like relative importance in history, physical condition, proposed use, and mandated code requirements. A treatment
is decided before any evaluation of alterations and additions; A. Kandt et al., Implementing Solar PV Projects on
Historic Buildings and in Historic Districts, National Renewable Energy Laboratory (September 2011): 18.

10
historic properties and the regulations to meet. In the early stage, projects will need to be defined
available locations with clear motivations like energy reduction or practicing renewable energy
use, etc. The goals of the project will dictate the type of people to be involved in later stages,
such as technical assistance or State Historic Preservation Officers, local historic districts boards
and so on. Second, the owners engage with different stakeholders and professionals for
assessment of historic properties: identifying the character-defining features and the potential
location for a PV system.
24
This is a significant step to integrate solar energy and to avoid any
negative impact on historic properties. After the implementation along with appropriate review
requirements, the NREL encourages people to evaluate the effects of a project by reviewing what
was successful in the project implementation and what could be improved upon, which could
increase the rate of success of such projects in the future.
25
In this stage, review criteria include
energy savings and system performance, the impact of historic integrity, and financial impact.
Successful cases and evaluations should be shared with all stakeholders in order to enlighten
other projects.
In general, those guidelines of implementing solar technology, mostly solar panels, will
help to increase sustainability in heritage conservation to some degree.
Considerations and Challenges
Although early guidelines and examples help to encourage the usage of solar energy in
historic sites, barriers still remain. As Elefante also writes in his essay, “Far too many
preservationists bristle at the mention of using renewable energy at historic sites.”
26
Conflicts
happen when properties’ owners consider financial aspects more than heritage conservation since
solar energy could create energy savings to some degree. Early examples allow solar energy
improvement in very limited cases with criteria to meet. A large number of properties will fail to
satisfy those criteria, especially when their face to the sun is on primary faç ades.
As preservationists try to balance historic integrity and sustainable energy improvement,
they face the challenge of the lack of comprehensive guidelines for sustainable energy at the
local level. Currently, the situation is uneven all around the country.

24
A. Kandt et al., “Implementing Solar PV Projects” 19.
25
A. Kandt et al., “Implementing Solar PV Projects” 28.
26
Elefante, “The Greenest Building,” 35.

11
Some local historic preservation commissions have adopted indicators for sustainable
improvement like solar collectors in their design guidelines, bridging aesthetics and
sustainability. The City of New Orleans encourages solar collectors for space heating, hot water,
and electricity in historic districts in the guidelines for roofing for the Historic District
Landmarks Commission. This guideline demonstrates that solar collectors shall be minimally
visible or hidden from public view – as far back from the front of the building wall as possible,
and a minimum of 10’-0” from the front building wall, or to be blended with their surroundings
if they could be visible.
27
Oklahoma City’s planning department also rewrote the city’s existing
historic preservation guidelines and standards with sustainability principles.
28
The new guideline
with “Green” revisions was published in July 2012 and contains a section of features for
improving energy efficiency with new construction on historic buildings. The installation of
solar panels and solar shingles are defined as “Actions that require review and may be
administratively approved” with four guidelines of installation positions: back facing roof slopes
and lay flat on roof slope, not on the front roof slope of south-facing buildings, free-standing
solar panels in backyards of south-facing buildings and solar panels with limited height in
backyards.
29
(Figure 1.2) The preservation ordinance of Breckenridge, Colorado, requires that
panels not be placed on a character-defining roofline or on a primary elevation, so as to not be
visible from the street.
30
Salt Lake City, Utah has compiled a set of design standards to measure
the visual impact of solar and skylights in their preservation handbook for historic properties.
31

In some cases, design standards for energy improvement like solar panels might not go
through the historic preservation ordinance. For example, in the city of Portland, Oregon, solar
panels are automatically permitted if they are on the rear facing part of the pitched roof.
32
In a

27
City of New Orleans HDLC, “Guidelines for Roofing” (April 2016): 05-10.
28
Catherine Montgomery, AIA and Phil Thomason, “Oklahoma City’s Green Guidelines: Combining Historic
Preservation Design Review and Sustainability Policy,” Forum Journal & Forum Focus, December 09, 2015,
National Trust for Historic Preservation, https://forum.savingplaces.org/viewdocument/greening-design-guidelines-
two-cas.
29
Thomason and Associates et al., Oklahoma City Historic Preservation Design & Sustainability Standards and
Guidelines, Oklahoma City, Oklahoma (July 2012): 121.
30
Kimberly Kooles, “Adapting Historic District Guidelines for Solar and Other Green Technologies,” Forum
Journal & Forum Focus, Volume 24, December 09, 2015, National Trust for Historic Preservation,
https://forum.savingplaces.org/viewdocument/adapting-historic-district-guidelin.
31
Salt Lake City, A Preservation Handbook for Historic Residential Properties & Districts (December 11, 2012):
7:7.
32
“Solar Energy in A Historic District,” Historic Laurelhurst, January 24, 2017,
https://www.historiclaurelhurst.com/single-post/2017/01/24/Solar-Energy-In-A-Historic-District.

12
proposed ordinance in Durango, Colorado, solar panels would be allowed in historic districts
without any regard for aesthetic considerations.
33
In other cases, the solar panels might be
reviewed by other departments rather than historic preservation commission. Maryland’s
Washington County zoning ordinance was recently amended to allow for solar panels and small
wind turbines in zoning districts without any indication for reviewing solar panels in historic
districts.
34

Fig 1.2: Solar roofs installations examples; left figure shows solar panels on a rear roof, the right figure shows a
wrong installation - the solar panels are visible from the public right-of-way. Source: Oklahoma City Historic
Preservation Design & Sustainability Standards and Guideline.
It should be kept in mind that the priority of heritage conservation is to conserve the
integrity of a historic property by keeping its significant features. Particularly, two of the seven
aspects of integrity should be considered:
Setting: Setting is the physical environment of a historic property that illustrates
the character of the place. Integrity of setting remains when the surroundings of
an aid to navigation have not been subjected to radical change. Integrity of setting
of an isolated lighthouse would be compromised, for example, if it were now
completely surrounded by modern development.
Feeling: Feeling is a property’s expression of the aesthetic or historic sense of a
particular period of time. It results from the presence of physical features that,
taken together, convey the property’s historic character.
35

The alteration of historic properties, such as the installation of modern energy
improvement can cause discord with original setting and feeling. Although renewable energy

33
Kimberly Kooles, “Adapting Historic District Guidelines.”
34
Kimberly Kooles, “Adapting Historic District Guidelines.”
35
U.S. Department of Interior, National Park Service, National Register Bulletin: How to Apply the National
Register Criteria for Evaluation, 1997: 45.

13
should be encouraged in historic sites, conducting projects without any concern for integrity is
not compatible with good practice. It is crucial to identify a better way of saving energy while
respecting the historical and cultural value.

14
Chapter 2: Understanding the Technology
The Solar Energy System
Current solar energy technology makes use of two types of solar resources: photovoltaic
(PV) and thermal. A PV system converts sunlight directly into electricity while a thermal system
uses the sun’s energy to heat liquid or gas to high temperatures.
36
Solar thermal systems are
better used in large energy plants while a solar PV system is usually an option for a home or
business.
In a PV system, the conversion of the sun’s energy into electricity is accomplished by the
use of PV cells composed of crystalline silicon and connected together into panels.
37
Many solar
panels combine together to create one system that is called a solar array.
38
Electricity generated
from the PV cells of the panels is passed through an inverter which converts the direct current
(DC) electricity into alternating current (AC) electricity that can be used by household
appliances.
39
PV systems located on or near a building are used to meet the electricity needs on
site. If the full electricity demands are not satisfied, additional energy is still provided by
conventional electrical systems.
40
If a solar energy system produces more electricity than the
users need, the surplus energy will enter the grid and be used to offset future electricity demand,
often showed by a customer’s meter spinning backwards.
41
Figure 2.1 illustrates a general
working principle of a solar panel system.
The adoption of solar panel systems in a historic site depend on variables like local
climate, installation costs, user demand, and the characteristics of the buildings, structure, and
site. Solar panels should be installed orienting south - any facing east or west will need to be
tilted to achieve optimum performance.
42

36
“What is Photovoltaics?” RGS Rethink Your Roof, September 17, 2015, https://rgsenergy.com/how-solar-panels-
work/what-is-photovoltaics/.
37
Installing Solar Panels on Historic Buildings: 6.
38
National Register Bulletin: How to Apply the National Register Criteria for Evaluation: 11.
39
Installing Solar Panels on Historic Buildings: 6.
40
Ibid.
41
Ibid.
42
Ibid.

15

Fig 2.1: Solar panel system. Source: Diagram is produced by author.

Evolving Technology – Solar Roof
With new technology, solar panels are invented in different shapes, and some can retain
the appearance and function of traditional building materials like roof shingles and tiles. This
new improvement for solar panels is called the solar roof.
43
It is usually referred to as “building-
integrated photovoltaic system,” which, unlike solar panels, can replace original roof shingles
and match the color while acting as a functional, protective, and weatherproof roof at the same
time. With this technology, it might be possible to reduce the loss of visual character in historic
districts compared to the addition of solar panels.
A solar roof consists of thin PV sheets that, like a solar panel, capture energy from
sunlight. They can be installed in any climate or environment and each sheet usually about
twelve inches wide.
44
A single solar roof tile is typically less than an inch thick. It has thin-film
solar cells made from either copper indium gallium selenide, which is said to have one of the

43
Solar roof, solar roof tiles and solar shingles all indicate a same product, which is a roof made of a number of PV
sheets. In this thesis, solar roof indicates the whole system while solar roof tiles indicate components of the PV
sheets.

16
highest conversion efficiency rates or monocrystalline silicon, a natural semiconductor used in
computer chips.
45
An individual roof tile only can produce between fifty to 200 watts, but linked
with others, 350 solar roof tiles could reduce forty to seventy percent of electrical power demand
from the public utility, and can potentially generate power equal to regular solar panels.
46

(Figure 2.2) The appearance of solar roof tiles vary by manufacturer, including textures that are
similar to asphalt shingles, red clay tile, slate, and smooth glass tiles, making them suitable for a
wide range of architectural styles.
47
There are products like Apollo Tile by CertainTeed Solar,
Sunslate6 by Aesthetic Green Power, Sun Roof by Tesla, etc. The full working principle as well
as detailed introduction of these solar roofs are listed in Appendix B and C.

Fig 2.2: A diagram of the connection of solar roof tiles. A full illustration of the solar roof tiles system is in
Appendix C. Source: Diagram is produced by author.
The solar roof tiles are also potentially less expensive to purchase than conventional
roofing tiles, especially in a new home which could be built with solar energy.
48
In the case of
existing property, homeowners could do the installation themselves or ask for help from an
electrician. The PV system is either connected to utility power or has batteries. The electricity
generated from the solar roof is connected directly to the power grid, saving cost to the owner. In

44
Size are various from different manufacturers, from 8.65 inches to 14 inches, 12 inches by 47 inches, to 12 inches
by 86 inches, and so on.
45
Alyssa Baker, “A Guide to Solar Roof Tiles: Shingles are The Next Big Thing,” Solar Power Authority,
https://www.solarpowerauthority.com/guide-to-solar-shingles/.
46
Keith Pandolfi, “Solar Shingles: A seamless appearance – and generous tax breaks – make rooftop power plants
more attractive than ever,” This Old House Insider, https://www.thisoldhouse.com/ideas/solar-shingles; Alyssa
Baker, “A Guide to Solar Roof Tiles.”
47
“Solar Panels vs. Solar Shingles – Pro, Cons, Comparisons and Costs,” Fixr,
https://www.fixr.com/comparisons/solar-panels-vs-solar-shingles.

17
a battery backup system, the PV tiles charge a battery to provide power for up to eight hours.
49

Also, company like Tesla is confident in the strength of the solar roofs. According to Tesla, it is
assumed that the material is warranted for the lifetime of a house since the glass used to make the
solar roofs is three times stronger than slate, clay, or terracotta.
50

There are some disadvantages of solar roof compared to solar panels. The biggest
problem of a solar roof is the high price of production and installation compared to traditional
solar panels. Even though some companies claim that users could see over a 200 percent return
of money in thirty years with the state and federal tax credits, there is no real conclusion yet.
51

Solar roofs may be less efficient than solar panels. Solar panels can be adjusted to the best angle
for sunlight exposure and solar roof tiles are fixed with the existing roof angle. As a result, solar
roofs will be more functional in a region with stable exposure to the sun.
As of August 2018, only twelve solar roofs had been reported to be installed in
California.
52
There are also some cases with solar roofs on residential properties in
Massachusetts. (Figure 2.3) Moreover, the solar roofs have been adopted on one certifiable
LEED building, the Thomas E. Curtis Wildlife Hospital and Education Center in Massachusetts.
The building uses solar roofs as the building integrated system to produce approximately five
percent of the whole building energy.
53
(Figure 2.4) Regarding to the aesthetic merit, there is an
expectation of replacement of solar panels with solar roofs. As the issues of climate change and
energy crisis grows, the costs of solar energy are expected to come down with a series of tax
credits.
Although there are few experimenting on historic landmarks currently, the implements of
solar roofs may lead to great progress on sustainable conservation. A solar roof with its ability to

48
Kyle Pennell, “The History and Future of Solar Shingles,” Altenergy Stocks, January 17, 2018,
http://www.altenergystocks.com/archives/2018/01/history-future-solar-shingles/.
49
Jenny Millward, “History and evolution of Solar Shingles,” Prezi, updated on February 26, 2014,
https://prezi.com/kvvsjb2dbsh4/history-and-evolution-of-solar-shingles/.
50
Hadley Keller, “What you should know before buying Tesla’s Solar Roof Tiles?” Beautiful House, April 23, 2019,
https://www.housebeautiful.com/home-remodeling/a27241892/tesla-solar-roof-tiles-facts-cost/.
51
Kyle Pennell, “History of Solar Shingles,” Solar Village, January 18, 2018,
http://www.thesolarvillage.com/content/news-post.cfm?news=628. Also, for instance, company like Solexel Inc. in
California produces a low-cost, high-efficiency solar shingle funded by $31 million in equity financing and a $13
million Department of Energy grant. From “The History and Future of Solar Shingles”
52
Luck Richardson, “Tesla Soar Roof: Elon Musk’s solar roof tiles complete review,” Energysage, January 3, 2019,
https://news.energysage.com/tesla-solar-panel-roof-the-next-solar-shingles/.
53
“Our Green Building,” New England Wildlife Center, https://www.newildlife.org/about-2/green-building/.

18
conserve the conventional roofline could be an effective way to bring sustainable energy
production to historic properties. Although the cost will likely be higher, under today’s
conditions, than the usage of solar panels, the incentives of preservation will also help
homeowners to access. There is a possibility that solar roof could produce more energy on a
historical roof than solar panels depending on the available locations of installation. The
following chapters will explore the possibility of adopting solar roof in historic districts with
evaluation of benefits and barriers.

Fig 2.3: Solar roofs installations on some residential houses; left figure is a red house in Bolton, Massachusetts, right
figure is a house with solar slates in Falmouth, Massachusetts. Source: provided by Aesthetic Green Power from
email.

Fig 2.4: The New England Wildlife Center’s green building in Massachusetts. Solar roofs have produced five
percent of total building energy. Source: “Our Green Building,” New England Wildlife Center,
https://www.newildlife.org/about-2/green-building/, photo rights authorized by e-mail.

19

Other Solar Technologies
Besides new invention like solar roofs, there are other alternative technologies that could
be used in historic properties and should be explored. “Community Solar” is a strategy to install
solar panels either on rural sites or on some of the many commercial roofs that exist in a
community. Owners will be able to buy or subscribe to a solar project elsewhere and receive the
benefits just as if the electricity were being generated on their own roof.
54
There is a type of solar
roof tile, which produces energy by absorbing thermal resources other than photovoltaic of the
sun. This type of solar tile could be designed along with traditional materials but will not be as
efficient as solar PV roof tiles.
55
This type may be best along with the historic properties with red
tile roof. Another technology like solar paving, which installs solar panels on a road rather than
on a building, will not cause visual issue like solar panels and could also be used in a historic
site.
56

54
“Solar Energy in A Historic District.”
55
Istvan Fekete, Istvan Farkas, “Numerical and experimental study of building integrated solar tile collectors,”
Renewable Energy (2018).
56
Dylan Ryan, “Solar panels replaced tarmac on a road – here are the results,” the Conversation, September 21,
2018, http://theconversation.com/solar-panels-replaced-tarmac-on-a-road-here-are-the-results-103568.

20
Chapter 3: Framework of Implementing Solar Energy in Historic Districts, Los Angeles
The History of Solar Energy in California
Located at the southwest of the United States, California is a state with high exposure to
the sunlight due to the dry climate and clear sky. According to National Renewable Energy
Laboratory (NREL), California is one of the states that have good photovoltaic solar resources in
the country. Some regions of California, like Daggett, can even reach 6.6 hours of exposure per
day. (Figure 3.1)

Fig 3.1: Billy J. Roberts, GIS map of U.S. solar resources, October 13, 2009. Source: National Renewable Energy
Laboratory for the US Department of Energy, (https://www.nrel.gov/gis/images/solar/national_photovoltaic_2009-
01.jpg).
California has a rich history of employing solar energy along with the development of
solar technology in the country. As mentioned in Chapter 1, the federal solar energy bill was
created in 1974 following the Oil Embargo. In 1978, the Congress passed the Public Utility
Regulatory Policy Act and the Energy Tax Act. These acts established the right for using solar

21
photovoltaic (PV) and encouraged tax credits for users. In 1979, ARCO Solar began to construct
the world’s largest PV manufacturing facility at that time, located in Camarillo California.
57

Then the Solar One project in 1981, the first test of a large-scale thermal solar tower and power
plant, was built in Daggett, California.
58
It continued to generate power until 1988, but shut
down due to low efficiency in storing energy. A redesign -- the Solar Two project served from
1995 to 1999 with a better storage system, producing energy that could be used by 7500 homes.
59

These two experimental projects pioneered solar technology and later led to more solar energy
projects on a large scale in the California desert.
From the 1990s to 2006, California developed a series of bills to encourage the usage of
solar energy. For example, the Electric Utility Industry Restructuring Act in 1996 (Bill 1890)
was established to deregulate the state’s investor-owned electric utilities and to create incentives
for grid-tied PV systems under the California Energy Commission’s Renewable Energy
Program.
60
Senate Bill 1345 in 2000 directed the state Energy Commission to develop and
administer grants to encourage the purchase and installation of solar energy systems.
61
By 2005,
renewable resources, including solar energy, were providing approximately eleven percent of the
state’s electricity mix.
62

In 2006, Governor Arnold Schwarzenegger announced “Go Solar California” at the Solar
Power 2006 Conference and Expo in San Jose. Go Solar California is a statewide effort based on
the “Million Solar Roofs” vision of California.
63
It includes two new solar incentive programs.
The Energy Commission provides incentives to energy efficient new home construction in the
New Solar Homes Partnership, and the California Public Utilities Commission gives rebates to
all other facilities in investor-owned utility territories.
64
Go Solar California has collected general

57
This was the first project to produce more than 1 megawatt (MW) of PV modules in one year, and for years later,
ARCO Solar dedicated a 6-megawatt PV facility in central California in the Carrissa Plain. “History of Solar Energy
in California,” Go Solar California, https://www.gosolarcalifornia.ca.gov/about/gosolar/california.php.

58
Ibid.

59
“Solar One and Solar Two: Decommissioned experimental solar facilitates that pioneered solar energy
technology,” Atlas Obscura, https://www.atlasobscura.com/places/solar-one-and-solar-two.
60
Ibid.
61
Ibid.
62
George Simons, Joe McCabe, California Solar Resources: In support of the 2005 integrated energy policy report,
Research and Development, Energy Research and Development Division, California Energy Commission, April
2005: 2.
63
“History of Go Solar, California!” Go Solar California,
https://www.gosolarcalifornia.ca.gov/about/gosolar/history.php.
64
Ibid.

22
information about incentives, solar rights, the development of solar energy in California, and
installation instructions on its website, providing helpful guidance for users to access solar
energy.
One of the most significant steps for California to ensure the popularization of solar
resources is the 1978 Solar Rights Act. It is a legal framework for protection to allow users to
access to sunlight and to limit the ability of homeowner associations and local governments from
preventing installation of solar energy systems.
65
For more than thirty years, it protected and
facilitated access to solar energy in California. The solar access rights also balance the needs of
solar system owners with other property owners. Along with the Solar Rights Act, the 1978 Solar
Shade Act further secure owners’ right by protecting the solar energy system from shading
caused by trees and shrubs on adjacent properties.
66
According to Go Solar California, planned
communities may sometimes try to limit the growth in the use of solar energy for various reasons,
but the enactment of California Solar Rights Act and the Solar Shade Act ensures the
homeowner’s ability to go solar.
By October 2018, the average electricity rate in California is about $0.1573 per kilowatt,
and the energy savings produced by solar panels could reach to $29,424 for a typical household
over twenty years with the good access to solar resources. (Note that this does not include the
average installation price for a 6kW solar system of $18,180)
67
The California Energy
Commission announced new standards in 2018 – to cut energy use in new homes by more than
fifty percent.
68
This goal is expected to reduce residents’ utility expenses in the long term and
save energy. To achieve this goal, the state requires all new homes and low-rise apartment
buildings to be constructed with solar panels starting in 2020. Although the mandatory standards
focus more on new construction, the goal for saving energy in California will no doubt increase.

65
“Solar Rights: Access to the Sun for Solar Systems”, Go Solar California,
https://www.gosolarcalifornia.ca.gov/about/gosolar/legislation.php.
66
Ibid.
67
Luke Richardson, “How Much Do Solar Panels Save?” Energysage, January 1, 2019,
https://news.energysage.com/much-solar-panels-save/.
68
Amber Pasricha Beck, “Energy Commission Adopts Standards Requiring Solar Systems for New Homes, First in
Nation,” California Energy Commission, released May 8, 2018,
https://www.energy.ca.gov/releases/2018_releases/2018-05-09_building_standards_adopted_nr.html.

23
Since existing buildings account for twenty-five percent of the state’s greenhouse gas emissions,
another crucial aspect is to retrofit these buildings with sustainable energy.
69

Solar Rights Act and Historic Resources
The 1978 California Solar Rights encourages the use of solar energy and reduce the
barriers like design review for aesthetic purposes throughout the state.
70
Local governments are
discouraged from adopting ordinances that would unreasonably restrict the use of solar energy
systems.
71
The state law also requires local governments to use a ministerial or administrative
application review instead of a discretionary review.
72
Along with the Solar Rights Act, the
Office of Historic Preservation (OHP), California, encourages the owners of historic properties
to install solar energy system followed the Guidelines on Sustainability from National Park
Service, which has been mentioned in Chapter 1, to minimize the impact to historic resources.
OHP also suggests that owners work with permit officials and preservation commissions to
provide guidance and installation details for conserving significant roofing materials and
character-defining features.
73

Although the Solar Rights Act discourages discretionary review, preservation
ordinances for adopting solar energy vary across California. Each city interprets
the state policy differently. For example, in the Duboce Park Landmark District in
San Francisco, the designation ordinance requires a Certificate of Appropriateness
for installations of solar structures:
A Certificate of Appropriateness for the installation of structures that support
solar panels, regardless of visibility, provided that the installation would not
require alterations to the building greater than normally required to install a solar
energy system, such as: (a) Set with a low profile, and (b) Mounted parallel with
the slope of the roof (if the roof is sloped greater than 1/12, and (c) Not visible
from adjacent street sightlines if on a flat roof, and (d) Set in from the perimeter
walls of the building, including the building’s primary façade.
74

69
Times Editorial Board, “Of Course California Should Require Solar Panels on New Homes,” Los Angeles Times,
May 11, 2018, https://www.latimes.com/opinion/editorials/la-ed-solar-new-homes-20180511-story.html.
70
“The 1978 California Solar Rights Act and Historic Resources,” California Office of Historic Preservation,
http://ohp.parks.ca.gov/?page_id=25664.
71
“California Government Code Section 65850.5.” California Legislative Information,
https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?sectionNum=65850.5.&lawCode=GOV.
72
Ibid.
73
“The 1978 California Solar Rights Act and Historic Resources,” California Office of Historic Preservation.
74
“Update: April 2013, Proposed Duboce Park Historic District,” San Francisco Planning, April 2013,
http://default.sfplanning.org/Preservation/landmark_districts/proposed/duboce_park/Duboce_Park_Update_2013.pdf.

24
In Santa Monica, the local zoning ordinance requires all solar energy systems proposed
on designated landmarks and historic district contributor properties to achieve a certificate of
appropriateness from the Landmarks Commission Liaison.
75
Installations would be evaluated
based on the Secretary of Interior’s Standards for Rehabilitation. Although likely rare, by
authorizing the liaison to act for the Landmarks Commission on these applications, the hearing
process is not required, and the review process can be expedited. The city of Orange has
classified the design review for alteration in historic districts into two types: Minor Design
Review (MDR) and the Design Review Committee (DRC). The MDR is for streamlining review
of repairs and minor rehabilitation like the installations of solar panels.
76
Also, there are some
cities like Los Angeles that do not require discretionary design review for solar systems
installations on a historic property per the state law.
The variety of preservation ordinances throughout the state will require preservationists
to be familiar with local regulations. Improper advice will otherwise generate unnecessary delay
or even damage on a historic property’s character, even causing the loss of designation. Also,
complicated issues might happen, such as installing a solar system for a non-contributing
property in a historic district. A circumstance like this will require preservationists to produce a
comprehensive plan for local residents. Preservationists will be more familiar with alternative
methods, such as using other technology like efficient windows and walls or encouraging owners
to buy credit in a solar farm. Recent evolving technology, such as the development of the solar
roof, will reduce visual degradation compared to solar panels. Thus, in a state with a rich history
of solar energy, the exploration of new technology on a historic property is important.
Solar Rights and Historic Districts in Los Angeles
Besides the context of solar technology in the state, Los Angeles itself is a region with a
long connection to solar energy. After the Oil Embargo, the first Solar Energy Society meeting
was held in Los Angeles in 1975 with an exhibition of solar components.
77
The Los Angeles
Department of Water and Power (LADWP) was one of the early designers of the first large-scale

75
Eileen Fogarty, “Ordinance Pertaining to Solar Energy Development and Design Standards (continued from
December 2, 2008),” City Council Meeting, Santa Monica, May 12, 2009,
https://www.smgov.net/departments/council/agendas/2009/20090512/s2009051207-A.htm.
76
Orange City Council, Historic Preservation Design Standards, the city of Orange, adopted on December 12, 2018.
77
Phillip James Tabb, “1970s: Solar Architecture,” 50.

25
thermal solar tower - Solar One, which was completed in 1981 and produced power from 1982 to
1988.
78

In 2018, Los Angeles was announced as the city in the United States with the most
installation of solar power systems. The city’s sustainable plan includes a clean and resilient
energy supply through the expansion of local solar resources. The growing installation of solar
power reflects that the city is streamlining produces for solar programs, making solar energy
more accessible to people.
79
In addition to the federal Solar Investment Tax Credit since 2006,
LADWP offers its own incentives like LADWP Solar Incentive Program for residents in Los
Angeles to offset the cost. These incentives make it more attractive for local residents to access
solar energy.
Also, solar technology is encouraged to be used in the large number of historic districts in
Los Angeles. The city adopted the Historic Preservation Overlay Zones (HPOZ) ordinance in
1979, for providing review of proposed exterior alterations and additions to historic properties
within those designated neighborhoods.
80
HPOZs include neighborhoods which are the most
intact historic communities with distinct architectural and cultural significance throughout the
city. There are currently thirty-five designated HPOZs in size ranging from approximately fifty
parcels to more than 4000 properties.
81
Many of the HPOZs have their own preservation plans.
Alterations as well as additions within HPOZ in Los Angeles will need to go through review by
HPOZ boards. Yet, the installation of solar systems is exempt from review under the California
Solar Rights Act to ensure solar access.
82
In the “Advisory Notice for Installing Solar Equipment
on Historic Buildings,” LADWP states:
In accordance with State Law (Assembly Bill 2188), permits for solar energy
installations affecting properties within Historic Preservation Overlay Zones
(HPOZs) or other designated historic resources, including City Historic-Cultural

78
“History of Go Solar, California!” Go Solar California,
https://www.gosolarcalifornia.ca.gov/about/gosolar/history.php.
79
“Los Angeles Named #1 Solar City in America,” Mayor Eric Garcetti, City of Los Angeles, April 4, 2018,
https://www.lamayor.org/los-angeles-named-1-solar-city-america.
80
“What is an HPOZ?” Office of Historic Resources, Los Angeles,
https://preservation.lacity.org/hpoz/homepage/about. Also, there are other historic districts in Los Angeles, which
are identified and formally determined eligible listed on the California Register or National Register that are not
designated HPOZs.
81
Ibid.
82
Office of Historic Resources, “Frequently Asked Questions (FAQs) on Proposed Historic Preservation Overlay
Zones (HPOZs).” Department of City Planning, Los Angeles.

26
Monuments, will not require clearances from the Department of City Planning. To
help maintain the character of historic districts, property owners are encouraged to
place rooftop solar panels on flat roofs, rear-facing rooftops, and other locations
that will minimize the visual impact of new solar equipment on individual historic
buildings and the historic district as a whole.
83

According to Lambert Giessinger, the historic preservation architect in the Office of
Historic Resources, a solar installation that is attached directly to the historic structure is exempt
from discretionary review in Los Angeles. The ideal way to install is the panels are not visible
from the public right-of-way.
84

As a result, HPOZs in Los Angeles could also play an important role in building a
sustainable city by adopting solar energy easily. It may still require local HPOZ boards to
provide guidance for users, in order to conserve historic neighborhoods’ character. Currently,
most installations of solar systems in HPOZs are solar panels. There is no case of installing a
solar roof on a historic property.
Summary of Solar Energy Legislation and Milestones
Years 1974 1975 1978 1996 2000 2006 2018
Federal
First solar
energy bill

Utility
Regulatory
Policy Act
Solar
Investment
Tax Credit
(30% tax
credit)

Energy Tax
Act
State
Solar Rights
Act
The Electric
Utility
Industry
Restructuring
Act (Bill
1890)
State Energy
Resources
Conservation
and
Development
(Senate Bill
1345)
"Go Solar
California"
New
standards,
starting in
2020
Solar Shade
Act
Los Angeles
Solar Energy
Society
meeting

The city with
most installed
solar power
systems
Table 3.1: Summary of the legal frameworks mentioned in Chapters 2 and 3. Source: Table is produced by author.

83
Los Angeles Department of City Planning, “Advisory Notice for Installing Solar Equipment on Historic
Buildings,” https://www.ladbs.org/docs/default-source/publications/misc-publications/solar-historic.pdf?sfvrsn=11.
84
Lambert Giessinger, email to author, February 11, 2019.

27
Evaluation Tool: L.A. County Solar Map
To evaluate the potential energy and money can be saved with a solar system, Los
Angeles County and Energy Upgrade California announced a new tool, the L.A. County Solar
Map in October 2012. The L.A. County Solar Map uses Geographic Information Systems (GIS)
to visualize and analyze energy savings per property within Los Angeles County. According to
Howard Choy, manager of the L.A. County Office of Sustainability, the map is a single source
for information about solar electricity, hot water, and energy efficiency projects, and
personalized information about their property like the potential installation locations of solar
panels.
85

On the website’s interface, users can easily access information by clicking a property.
The map directly shows the property’s rooftop area and shade place as well as detailed costs,
savings, and potential payback for installing a solar system. The potential area for solar
installation is visualized in a set of colors: red is the best access to solar, orange means good
access to solar, green is poor access to solar, and blue represents not available to solar resource.
(Figure 3.2) An even more detailed rooftop report presents additional information like the range
of energy savings possible and the estimation process. (Appendix D) Chapter 4 will use the LA
County Solar Map to evaluate potential energy saving with solar roofs in a historic district in Los
Angeles.

85
Nick Franchino, “Los Angeles County Solar Map,” Los Angeles County, Department of Regional Planning, last
updated October 6, 2015, http://planning.lacounty.gov/solar/.

28
Fig 3.2: The interface of LA County Solar Map. Source: LA County Solar Map website,
(http://egisgcx.isd.lacounty.gov/solar/m/?viewer=solarmap).

29
Chapter 4: A Good Candidate – Western Heights HPOZ, Los Angeles
In order to explore the possibility of adopting solar roofs in a historic district, the Western
Heights Historic Preservation Overlay Zone (HPOZ) in Los Angeles has been selected as a
candidate.
A Brief History of Western Heights HPOZ
Western Heights is west of the original land grant given to Spanish settlers in 1781 and
was used exclusively for grazing and agriculture until the later part of the nineteenth century.
(Figure 4.1) In 1896, it was included in the third annexation of the City of Los Angeles. Due to
the introduction of horse-drawn streetcars, it was later developed as a suburban neighborhood for
those families who worked downtown Los Angeles. In the 1920s, the population in south Los
Angeles’s neighborhoods grew rapidly. The growth encouraged the development of more
residential structures, including multi-family properties like apartments. After the 1930s, the
routes of streetcars and electric railways had further encouraged the residential development of
south Los Angeles. The “suburbanization” movement extended to outlying farm communities.
(Figure 4.1) The nearby the resources of water distribution, including artesian wells and larger
water distribution stations erected by the Los Angeles Department of Water and Power also
enabled Western Heights to be developed as a concentrated residential area.

30

Fig 4.1 Left: An orchard at the intersection of Washington Boulevard and Western Avenue in 1899, Los Angeles,
CA, 1899. Source: USC Libraries/California Historical Society Collection, 1899; filename CHS-6414
(http://digitallibrary.usc.edu/cdm/singleitem/collection/p15799coll65/id/3965/rec/5); Right: The streetcar lines on
the intersection of Washington Boulevard and Western Avenue in 1935, Los Angeles, CA, 1935. Source: USC
Libraries/ “Dick” Whittington Photography Collection,1924-1987; filename DW-1935-03-05-27
(http://digitallibrary.usc.edu/cdm/compoundobject/collection/p15799coll170/id/58992/rec/17).
Today, the Western Heights neighborhood is located north of the Santa Monica Freeway
in the West Adams neighborhood. It is approximately bounded by Arlington Avenue on the west,
Western Avenue on the east, Washington Boulevard on the north, and the Santa Monica Freeway
on the south. Although Western Heights later developed commercial storefronts on the
Washington Boulevard, the neighborhood has remained mostly unaltered in the last eighty years
with over seventy percent of buildings retaining their historic character. It was designated as a
HPOZ on March 2, 2001, with 127 of 175 properties identified as contributing resources.
86
(Figure 4.2) Compared to the historic map of the neighborhood in Figure 4.3, many of the
contributing properties remain the same. (Figure 4.2, 4.3)
It retains significance in the contexts of the development of the streetcar network, the
annexation of Los Angeles, and residential development with single family structures and multi-

86
Contributing resources are any building, structure, landscaping, natural feature identified on the Historic
Resources Survey as contributing to the historic significance of the Historic Preservation Overlay Zone including a
building or structure which has been altered, where the nature and extent of the alterations are determined reversible
by the Historic Resources Survey. Generally, contributing structures would have been built within the historic period
of significance of the HPOZ, and will retain elements that identify it as belonging to that period; Citywide HPOZ
Ordinance NO. 184903, Los Angeles Municipal Code, http://clkrep.lacity.org/onlinedocs/2016/16-
1157_ord_184903_5-5-17.pdf.; all information about Western Heights HPOZ in this chapter, unless additional noted,
is from the Western Heights HPOZ Preservation Plan, adopted by the City of Los Angeles on December 9, 2010.

31
family structures. It also contains resources associated with the minority heritage of Los Angeles.
The period of significance of the Western Heights HPOZ extends from the 1860s to the 1950s.

Fig 4.2: The HPOZ map of Western Heights with all contributing properties. Source: Diagram is produced by author
based on the Western Heights HPOZ survey map and ZIMAS, Office of Historic Resources, City of Los Angeles
Department of City Planning, (https://preservation.lacity.org/files/Western%20Heights%20Survey%20Map.pdf).

Fig 4.3: Historic Sanborn Map 1921 with contributing properties in the HPOZ today. Source: Compiled by author
based on the Los Angeles Sanborn maps vol.8, 1921, Digital Sanborn Maps 1867-1970,
(http://sanborn.umi.com.libproxy1.usc.edu/ca/656/dateid-000007.htm?CCSI=20518n ).

It is a quiet neighborhood in a trapezoidal shape, bounded by greenbelt at the south and
storefronts at the north. A plaque with “Western Heights” is sitting at the intersection of
Gramercy Place and West 21
st
Street. Streets are paved with asphalt, concrete sidewalks line the
streets, and the parkway has mature trees. (Figure 4.4) The houses are in various architectural

32
styles and still remain harmonious. Most of them have small front yards without fences, merging
into the streetscape. Some of the houses display small flags with signs “Historic West Adams” in
front of the door, celebrating their historic properties. (Figure 4.5, 4.6)
In general, this is a streetcar neighborhood in a low scale. The roofline is visible from the
pedestrian perspective and thus it is one of the significant features of the historic district that
should be maintained appropriately. Many of the historic roofs have already been altered in this
neighborhood and some are not in a very good condition. (Figure 4.7) Yet, this condition that
requires further maintenance might also provide an opportunity for new rehabilitation project,
such as adopting sustainable technology systems.
Fig 4.4: The Western Heights HPOZ. Source: Photos by author.
Fig 4.5: Buildings are in various architectural styles and still remain harmonious. Source: Photos by author.

33

Fig 4.6: Some properties have small flags to celebrate their historic resources. Source: Photos by author.

Fig 4.7: Some contributing properties are not in good condition and will need maintenance. Source: Photos by
author.
Architectural Styles and Roof Features of the Western Heights HPOZ
From the 1920s to the 1950s, the rapid population growth and streetcar development let
south Los Angeles continue to have powerful residential construction. Many residential
neighborhoods were developed in a very short time with a single developer, and thus were
consistent to one architectural style. In later decades, residential development continued to
change as older structures were replaced by newer ones. These neighborhoods have a variety of
architectural features regarding the changes in population, income level, and generations. Thus,
with a long period of significance from the 1860s to the 1950s, the Western Heights HPOZ

34
contains buildings in various architectural styles, ranging from American Four Square, Queen
Anne, Craftsman, and Spanish Colonial Revival, etc.
The residential streets of Western Heights are characterized by two and two-and-one-half
story single family residences.
87
The single-family home was the predominant resource type of
Western Heights in a variety of sizes, scales, site characteristics, and architectural styles. Some
of these houses were designed by some of the most prominent architects of Los Angeles, such as
Myron Hunt and Paul R. Williams. The Western Heights HPOZ Preservation Plan describes the
single-family homes in western Heights as:

Craftsman bungalows included the stone foundations, porch supports, and
chimneys that typified the style. Wood sheathing or shingles, protruding rafters,
the low, horizontal emphasis, and other hallmarks combined to create a regional
aesthetic loosely derived from the Arts and Crafts Movement in England and
America. Colonial Revival examples typically included a symmetrical facade with
columns flanking the doorway. Clapboard sheathing and clipped gable roof forms
were also typical. The Spanish Revival and Mission styles had stucco walls, red
tile roofs or overhangs, and frequently incorporated arched windows and details
as well as other elements derived from the California missions. Tudor style homes
included steeply pitched roofs and stucco and half-timber wall designs.
Multi-family residential structures in Western Heights include duplexes, bungalow courts,
and apartments. Many of them included outdoor open space like courtyards or gardens, creating
a relationship between living space and the landscape.
For implementing solar roofs in the Western Heights HPOZ, a specific summary of
architectural styles with roof features is listed in table 4.1. (Table 4.1) A complete illustration of
the architectural styles of the Western Heights HPOZ is included in Appendix E.

87
“Western Heights,” Office of Historic Resources, City of Los Angeles,
https://preservation.lacity.org/hpoz/la/western-heights.

35
Styles General Characteristics Roofing systems Examples
American
Foursquare
Simple floor plan
Boxy, cubic shape
Two to two-and-a-half stories
Large central dormer
Simple and restrained two-color
and three-color paint schemes
highlighting body, trim and
accents
Pyramidal, hipped roof,
often with wide eaves
Shingle roof

Classical
Revival
Massive symmetrical and
rectilinear form
Triangular pediments supported by
classic columns
Large rectangular windows usually
arranged singularly
Masonry walls
Color schemes indicative of stone
and masonry construction
Low pitched roof
Shingle roof

Queen Anne Highly ornamented with spindle
work, finials, roof cresting, corner
brackets on porches and cutouts
Fanciful shingle and clapboard
Covered porches often wrap from
the front and around side and are
decorated with spindle work and
friezes
Complex and contrasting color
schemes highlight ornate wood-
work
Complex and steeply
pitched roof forms with
cross gables and front-
facing gables, roof
cresting
Shingle roof

Shingle Asymmetrical facades
Clad with naturally stained shingle
Rough-hewn stone foundations
and porch supports
Rectangular, grouped, double-
hung windows
Stained shingles in natural tones
with one or trim trim/accent colors
Asymmetrical roof forms
Complex cross-gables
and front-facing gables
Occasional use of
gambrel roof
Shingle roof

Colonial
Revival
Symmetrical facades, and
occasional use of side-porch
Basic rectangular shape
Central entrance usually adorned
with pediments and decorative
crown
Diminutive or no front porch
Two or three-color paint schemes
with house body often in light or
white tones
Hipped or side-facing
gable roof
Shingle roof

36
Styles

General Characteristics Roofing systems Examples
Craftsman Pronounced front porch, symmetrical
or offset with massive battered or
elephantine columns
Grouped rectangular multi-pane
windows
Massive stone or masonry chimneys
Use of earth tone color palette and
natural finishes
Three-color schemes for body, trim
and accents
Broad gabled roofs with
deeply overhanging eaves
Shingle roof

Mission
Revival
Simple, smooth stucco or plaster
siding
Large square pillars or twisted
columns
Arched entry and windows with deep
openings
Covered walkways or arcades
Round or quatrefoil window
Restrained decorative elements
usually consisting of tile, iron, and
wood
Either hipped or gabled
tile roof
Roof parapets
Clay tile roof

Dutch
Colonial
Revival
One-and-half to two stories
Clapboard, shingle, stone or stucco
siding
Typically, symmetrical facades, but
also found with side entries
Gable-end chimneys
Porch under overhanging eaves with
simple classical columns
Shed, hipped, or gable dormers
Gambrel roof, side gables
widely used
Shingle roof

English
Tudor
Revival
One-and-one-half to two stories with
asymmetrical and irregular plan
Use of half-timbering, patterned
masonry, stone and stucco
Over scaled chimneys with
decorative brick work and chimney
pots
Rectangular or arched doorways,
often recessed or found within tower
features
Cross-gabled, medium to
steeply pitched roof,
sometimes with clipped
gables
Shingle roof

Italian
Renaissance
Revival
Moderate to wide eaves with
decorative bracket supports
Recessed porches with arched
openings
Most often symmetrical
Balanced wings
Use of three-color palette with
subdued and formal tones
Low pitched, hipped tile
roof
Tiles in reds, greens and
blues

37

Styles

General Characteristics Roofing systems Examples
Mediterranean
Revival
Rectangular or irregular plans
Arched and rectangular windows
and doors
Balconies, patios and courtyards
integrated into plan
Vibrant two and three-color
schemes with walls in shades
reminiscent of adobe
Varied, irregular roofs
with simple eaves
Clay tile roof

Table 4.1: Architectural styles and roof features of the Western Heights HPOZ. Table is produced by author based
on the Western Heights HPOZ Preservation Plan, all photos by author.

In general, although the Western Heights HPOZ includes many architectural styles, the
most common roof forms are in hipped and gabled. According to the Western Heights HPOZ
Preservation Plan, the colors of roof shingles are in earth tones such as rusty reds, greens, and
browns rather than light colors, and thus could be compatible with solar roof tiles’ color.
Rehabilitation Guideline
The Western Heights HPOZ Preservation Plan, adopted in December 2010, ensures the
vitality of the Western Heights HPOZ as a livable and sustainable neighborhood through the
restoration, preservation, and enhancement of structures, landscaping, and natural features.
(Appendix E) The plan presents design guidelines for rehabilitation and restoration projects
within the Western Heights HPOZ. The Western Heights HPOZ Board conducts a review
process, in conjunction with the staff of the Planning Department, based on this Preservation
Plan.
88
This plan also serves as an educational tool for both existing residents and potential
property owners, residents, and investors in the future to learn more about this HPOZ. Since
most of properties in the Western Heights HPOZ are single family residential structures, a
Residential Rehabilitation Guideline is a crucial part of the preservation plan, which is mostly
adopted and used in planning, reviewing and executing. This guideline ensures that historic
properties in the HPOZ can still retain elements to be identified within the historic period of
significance.

88
HPOZ has different review processes for different types of project, such as Certificate of Appropriateness,
Certificate of Compatibility, Conforming Work on a contributing element, Conforming Work on non-contributing
Elements, more information goes in Appendix E, Chapter 3.4.

38
In order to install solar energy system on historic properties properly without loss of
visual character, the users should refer to the sections of roofs and mechanical equipment of this
Rehabilitation Guideline. For rehabilitation of roofs, the guideline states that:
5. Historic specialty roofing materials, such as tile, slate, gravel or built-up
shingles, should be preserved in place or replaced in kind. Wood roof shingles are
no longer permissible in Los Angeles, and where possible, special care should be
taken to make minimal repairs to wood shingle roofs rather than replace the roof
outright.
6. Replacement roof materials, where in-kind replacement is not possible, should
convey a scale, texture, and color similar to those used originally.
8. Skylights or solar panels should be designed and placed in such a way as to
minimize their impact. Locations on the side and rear facades are preferred for
skylights. Where skylights are found appropriate, they should be flat and
relatively flush to the roof surface.
In the meanwhile, the guideline encourages historic properties to adopt new mechanical
systems like modern heating and cooling systems, electrical systems, and solar panels, meeting
criteria like “the location of one of these elements may not seem to make a significant negative
impact on a structure or neighborhood.” For installation of solar panels specifically, the guideline
states that:
8. Solar panels should not be placed upon rooftops that are visible to the general
public. Location upon detached garages in many instances will be appropriate, or
upon rear-facing roofs that are minimally visible from a public street. Solar panels
should be low in profile and should not overhang or alter existing rooflines.
While the Rehabilitation Guideline of Western Heights HPOZ provides detailed criteria
for solar system installation, the review of installation is delegated to the Director of Planning if
the installations are not visible from the street. As mentioned in Chapter 2, the installations of
solar systems are exempt from review under the California Solar Rights Act. As a result, most of
installations of solar systems are not reviewed by HPOZ Boards in public hearings. The
guideline hasn’t included any criteria for installation of solar roofs yet, which needs to replace
parts of original roof materials, but unlikely causes visual degradation compared to solar panels.
The use of solar roofs will maintain the historic roofline by replacing the historic roof
materials with elements of the same scale. According to Preservation Brief on Substitute
Materials, it is possible to replace historical materials with newer products that match the historic

39
character of the original, if there is long term benefit such as cost-effectiveness.
89
The
Preservation Brief suggests four circumstances to consider before using substitute materials: 1)
the unavailability of historic materials; 2) the unavailability of skilled craftsmen; 3) inherent
flaws in the original materials; and 4) code-required changes.
90
For roofing rehabilitation project
specifically, the Preservation Brief states that roof materials could be replaced with valid reasons,
but the decision to use an alternative material should be weighed carefully.
91
If the roof is readily
visible, the alternative material should match as closely as possible the scale, texture, and
coloration of the historic roofing material.
92
The case of using solar roofs is not one of these four
circumstances yet will lead to the improvement of the whole historic building while matching
historic character at the same time. Further guidelines should be set to address the application of
replacing historic materials with solar roof tiles’ materials. New preservation guideline should
also discuss the possibility of installing solar roofs on a street-view elevation.
Being a Good Candidate of Implementing Solar Roofs
There are several reasons for choosing the Western Heights HPOZ in Los Angeles as a
location to exploration of implementing solar roofs.
First of all, the scale of the Western Heights HPOZ is practical for conducting a field
survey because there are only about 127 contributing resources to document. Second, the
orientation of buildings in the Western Heights HPOZ makes them good candidates for the
installation of solar systems. The latitude of Los Angeles is 34.0522° N, meaning that the city is
located north of the Tropic of Cancer and can only accept sunlight from the south.
93
As figure
4.8 shows, most of the buildings in this HPOZ are north or south-facing, and thus will have a
large roof area to accept the sunlight. (Figure 4.8)

89
Sharon C. Park, “Preservation Briefs 16: the Use of Substitute Materials on Historic Building Exteriors,”
Technical Preservation Services, National Park Service, U.S. Department of the Interior, accessed September 1988,
https://www.nps.gov/tps/how-to-preserve/briefs/16-substitute-materials.htm.
90
Ibid.
91
Sarah M. Sweetser, “Preservation Briefs 4: Roofing for Historic Buildings,” Technical Preservation Services,
National Park Service, U.S. Department of the Interior, accessed February 1978, https://www.nps.gov/tps/how-to-
preserve/briefs/4-roofing.htm#materials.
92
Ibid.
93
“Los Angeles, United States latitude, longitude,” Latitude, Longitude.org, https://latitudelongitude.org/us/los-
angeles/; “Latitude,” Enviropedia, http://www.enviropedia.org.uk/Climate/Latitude.php.

40

Fig 4.8: Satellite view of the Western Heights HPOZ. Source: Map is produced by author based on Google Maps.

In addition, the roof forms of the Western Heights HPOZ will be suitable to implement
solar roofs. Figure 4.9 shows an analysis of roof forms suitable for installation of solar roofs. In
general, side-gabled/gambrel roofs facing south/north, front-gabled/gambrel roofs facing
east/west, and hipped roofs with appropriate area to use solar systems, make good candidates for
solar roofs.
94
Although there are numerous architectural styles in the Western Heights HPOZ,
most of the roof forms are gabled-roofs and hipped roofs with houses facing south or north, and
therefore can be compatible with solar roofs. Figure 4.10 shows a solar map of parts of historic
properties that will have good access to solar resources.

94
The building orientation / facing is based on the elevation facing the street with main entrance way.

41

Fig 4.9: A diagram of the roof forms suitable for solar roofs. Source: Diagram is produced by author.

Fig 4.10: The solar map of a portion of the Western Heights HPOZ; the red color shows the best access to solar
resources while the orange color shows good access. Source: L.A. County Solar Map
(http://egisgcx.isd.lacounty.gov/solar/m/?viewer=solarmap).

42
As mentioned in Chapter 1, the current technology of solar roof tiles is more compatible
with slate roofs, dark color shingle roofs, and possibly red clay tile roofs.
95
In order to achieve
the goal of installing solar roofs without loss of historic character, the appropriate roofs for
installation are in these three types of roofs. (Figure 4.11) In the Western Heights HPOZ, many
of historic properties use shingle roofs in dark colors, and thus will be workable to explore the
possibility of adopting solar roofs.

Fig 4.11: The roof materials that can be compatible with solar roof tiles. Source: Figure is produced by author.

In conclusion, the Western Heights HPOZ is a good candidate to explore the possibility
of adopting solar roofs due to its scale, building orientation, roof forms, and roof materials.
Furthermore, the variety of architectural styles in the Western Heights HPOZ provides a valuable
chance to explore the impact of solar roofs on different architecture forms.

95
The solar roof tiles that are compatible to red clay tile are only proposed by Tesla Company currently and they
have not been produced yet.

43
Chapter 5: Adopting Solar Roofs in the Western Heights HPOZ
Research Methods
Although the implementation of solar roofs is likely to maintain the historic character of a
property, the energy efficiency of solar roofs is another thing to consider. In this chapter,
research was conducted for analyzing and calculating the potential energy production of solar
roofs in the Western Heights Historic Preservation Overlay Zone (HPOZ). The research focuses
on how efficient solar roofs can be compared to solar panels.
The research project design has five steps. (Figure 5.1) In Step 1, a field survey was taken
in order to identify appropriate properties which might install solar roofs. Solar roof products are
more compatible with grey, dark grey, blue, or dark blue roofs, while the roofing materials can
be in shingle, slate, or red clay tile. A map with all candidates was drawn after the field research
of the Western Heights HPOZ. In Step 2, a new solar map for these candidates was produced by
combining the map from Step 1 and the L.A. County Solar Map. In Step 3, a spreadsheet was
created to collect information on each candidate home, including address, roof plane types,
orientation, roof materials, color, roof total area, suitable total area for solar photovoltaic (PV)
based on the L.A. County Solar Map, and suitable area for using solar panels meeting the
preservation guideline.
In Step 4, the solar panels potentials of the area meeting the preservation guideline will
be set as the reference group. The calculation and comparison are given in two ways: using solar
roofs on the same area as the solar panels and using solar roofs on all area that is available to
solar PV as the L.A. County Solar Map suggests.

44

Fig 5.1: Flowchart of research methods. Source: Produced by author.
Field Survey
The analysis and calculation of adopting solar roofs will be given regarding only
Contributing properties of the Western Heights HPOZ. In order to identify candidates that could
use solar roofs, a field survey was conducted to document each contributor’s roof plane types,
house orientation, roof plane materials, and color. Table 5.1 shows an example of the spreadsheet
that has been designed for documenting details of each property and the full documentation is
compiled in Table 5.2. (Table 5.1)
5. Data analysis and conclusion
4. Calculation in two ways of installing solar roofs:
a) Installing solar roofs on the same area as solar panels
b) Installing solar roofs on all suitable area for PV as the L.A. County Solar Map
suggests

3. Spreadsheet of total roof area, suitable area for PV, suitable area for solar
panels, approximate maximum energy production with solar panels on roof area
meeting preservation design guideline
2. Produce a new solar map
1. Field survey to identify candidates with compatible roofing

45
Number
Site
Address
Roof Plane
Types
Orientation
Roof Plane
Materials
Color Possibility
2371 W 20TH ST Hip roof South Shingle Dark grey √
2361 W 20TH ST Front Gable South Shingle Dark grey √
2355 W 20TH ST Side Gable South Shingle Dark grey √
Table 5.1: An example of the spreadsheet that used to document the contributors of the Western Heights HPOZ.
Source: Table is produced by author.
The survey documents the current condition of the installation of solar technology within
the HPOZ. It is notable that there are three contributing properties with solar panels on top of
their side roofs. Although the installations are with setbacks, the panels can still be viewed from
the street level. (Figure 5.2, 5.3) In the meanwhile, there is one non-contributing property,
located at a crossroad and next to a contributing property, with solar panels in all directions on
the roof. The panels can be seen even across the street, causing discord in the historic
neighborhood. (Figure 5.4)
Fig 5.2: Contributing properties with solar panels. Source: Photos by author.

46

Fig 5.3: A Contributing property with solar panels on both sides of the gable front roof and not visible from directly
in front with no impact to the roofline. Source: Photos by author.

Fig 5.4: A non-contributing property with solar panels in all directions next to a contributing property. Source:
Photos by author.

47
Most of the historic properties in the Western Heights HPOZ have roofs in earth-tone
colors like grey, dark grey, dark green, and brown. The survey identifies those who in grey, dark
grey, dark green, and red clay tile roofs as candidates that might be compatible with solar roofs.
Given the current solar roofs products available, shingle / slate roofs in brown color and red
color would not be appropriate. (Figure 5.5) Figure 5.6 is a map documenting all candidates with
their roof colors.
Fig 5.5: Roof colors that will not be compatible with solar roofs. Source: Photos by author.

48
Fig 5.6: Map of all candidates with their roof colors. Source: Figure is produced by author.
Analysis and Comparison
The field survey identified fifty-nine properties out of 127 total contributing properties as
candidates for adopting solar roofs. Based on the survey, a new solar map was drawn to
document each property’s access to solar resources. (Figure 5.7) Information from the L.A.
County Solar Map including the rooftop area, area suitable for solar resources, and solar
photovoltaic (PV) potential is collected in Table 5.2, in preparation for later calculation.

49
Fig 5.7 Solar map of all candidates in the Western Heights HPOZ. Source: Figure is produced by author based on
L.A. County Solar Map.
Table 5.2 shows the calculation and comparison of adopting solar roofs in the Western
Heights HPOZ. There are several points that need to be explained:
 “Suitable Area for PV (Sq. Ft)” means the total roof area that is available
to solar PV resource, provided by the L.A. County Solar Map. “Suitable Area for Solar
Panels (Sq. Ft)” is calculated by the author based on the area that could install solar
panels in keeping with preservation design guideline. For example, areas like rear roofs
and side roofs that are rarely visible from street level. As a result, “Solar Panels Potential
(kWh/day)” in the table is not the same as the solar PV potential exactly provided by L.A.
County Solar Map, which is the maximum energy production of using solar panels on all
suitable area. Also, some properties in the historic district that could not install solar
panels due to visual impacts will have a zero score in the table.
 The data of energy efficiency of solar roofs is based on three companies’
products in different exposed area, as well as maximum power: 1) the Apollo Tile,
produced by CertainTeed Solar, has size of 46” × 13.25” with maximum power 63 Watts
per tile / 14.89 Watts per square foot; 2) the Sunslate6, produced by Aesthetic Green
Power, has size of 14.5” × 19.688” with maximum power 23 Watts per tile / 11.6 Watts
per square foot; 3) the Sun Roof, produced by Tesla, has size of 8.65” × 14” with

50
maximum power 12 Watts per tile / 14.3 Watts per square foot.
96
Full information of
Apollo Tile and Sunslate6 is displayed in Appendix B and C. (Appendix B, C) Although
they are in various sizes, the unit conversion indicates that they all have similar energy
efficiency per square foot, which is about 14 Watts. The calculation in Table 5.2 uses 14
Watts per square foot as the solar roofs’ energy production.
 The potential output of solar panels is measured in kWh per day. This is
calculated by multiplying solar PV potential system size in kW by 5.3 hours of
generation per day, based on the calculation method from the solar rooftop potential
report by L.A. County Solar Map. (Appendix D)
 The potential output for the solar roof multiplies the calculated area by 14
Watts per square foot by 5.3 hours of generation per day times 1 kW. The calculation
includes two ways with different calculated area: 1) to use the same roof area that solar
panels use for solar roofs (“Solar Roofs as Panels, kWh/day”); 2) to use the solar roofs on
all area that are suitable for PV, provided by L.A. County Solar Map (“Solar Roofs on
All Suitable Area, kWh/day”). For example, the #8 property has 225 square feet suitable
area for PV, but only 50 square feet could be installed with solar panels due to visual
issues. In the “Solar Roofs as Panels, kWh/day” column, the calculation adopts 50 square
feet, while for the “Solar Roofs on All Suitable Area, kWh/day” column, the calculation
adopts 225 square feet.

96
46” × 13.25” with maximum power 63 Watts is Apollo Tile by CertainTeed Solar,
https://www.certainteed.com/resources/ApolloTileIITDS.pdf;
14.5” × 19.688” with maximum power 23 Watts is Sunslate6 by Aesthetic Green Power,
http://aestheticgreenpower.com/wp-content/uploads/2018/04/Sunslates6-Specs-Rev2.0.pdf; 8.65” × 14” with
maximum power 12 Watts is Sun Roof by Tesla, https://electrek.co/2017/06/20/tesla-solar-roof-more-details-
certification/.

51
# No.
Site
Address
Roof
Plane
Types
Orientation
Roof
Plane
Materials
Color
Rooftop
Area
(Sq. Ft)
Suitable
Area
for PV
(Sq. Ft)
Suitable
Area for
Solar
Panels
(Sq. Ft)
Solar
Panels
Potentials
(kWh/day)
Solar
Roofs as
Panels
(kWh/day)
Solar
Roofs on
All
Suitable
Area
(kWh/day)
1
2371
W 20TH
ST
Hip South Shingle Dark grey 2066 50 50 5.3 3.7 3.7
2
2361
W 20TH
ST
Front
gable
South Shingle Dark grey 3046 225 225 21.2 16.7 16.7
3
2355
W 20TH
ST
Side
gable
South Shingle Dark grey 2820 400 × × × 29.7
4
2351
W 20TH
ST
Front
gable
South Shingle Dark grey 3263 150 100 10.6 11.1 11.1
5
2325 W 20TH
ST
Cross
gable
South Shingle Grey 2258 425 × × × 31.5
2327
6
2315
W 20TH
ST
Hip South Shingle Dark grey 2147 50 × × × 3.7
2317
7
2307
W 20TH
ST
Front
gable
South Shingle Grey 2117 150 × × × 11.1
8
2287
W 20TH
ST
Front
gable
South Shingle Dark grey 2836 225 50 5.3 3.7 16.7
9
2279
W 20TH
ST
Cross
gable
South Shingle Dark grey 2516 150 150 15.9 11.1 11.1
10
2265
W 20TH
ST
Cross
gable
South Shingle
Dark
green
1697 100 × × × 7.4
2267
11
2255
W 20TH
ST
Cross
gable
South Shingle Dark grey 2709 25 × × × 1.9
2257
12
2237
W 20TH
ST
Hip South Shingle Dark grey 1794 50 × × × 3.7
13
2231
W 20TH
ST
Cross
gable
South Shingle Grey 2091 225 225 21.2 16.7 16.7
14
2225
W 20TH
ST
Cross
gable
South Shingle Dark grey 1944 125 125 10.6 9.3 9.3
15
2179
W 20TH
ST
Hip and
gable
South Shingle Grey 3010 150 150 15.9 11.1 11.1
16
2143
W 20TH
ST
Cross
gable
South Shingle Dark grey 4459 300 300 26.5 22.3 22.3
17
2129
W 20TH
ST
Cross
gable
South Shingle Dark grey 2578 100 100 10.6 7.4 7.4
18
2376
W 20TH
ST
Cross
gable
North Shingle Grey 1699 0 0 0 0.0 0.0
19
2364
W 20TH
ST
Cross
gable
North Shingle Grey 1438 50 50 5.3 3.7 3.7
2366
20
2354
W 20TH
ST
Hip North Shingle Dark grey 2595 125 125 10.6 9.3 9.3
2356
21
2342
W 20TH
ST
Hip North Shingle Dark grey 2191 50 50 5.3 3.7 3.7
2344
22
2298
W 20TH
ST
Hip and
front
gable
North Shingle Dark grey 2328 100 100 10.6 7.4 7.4
23
2294
W 20TH
ST
Gambrel North Shingle Dark grey 1806 0 0 0 0.0 0.0
24
2288
W 20TH
ST
Cross
gable
North Shingle Dark grey 2372 150 150 15.9 11.1 11.1
25
2280
W 20TH
ST
Cross
gable
North Shingle Dark grey 2361 275 275 26.5 20.4 20.4
26
2260
W 20TH
ST
Cross
gable
North Shingle Dark grey 2636 75 50 5.3 5.6 5.6
2262
27
2250
W 20TH
ST
Cross
gable
North Shingle Dark grey 2910 200 200 15.9 14.8 14.8
28
2236
W 20TH
ST
Side
gable
North Shingle Dark grey 3254 375 375 31.8 27.8 27.8

52

# No.
Site
Address
Roof
Plane
Types
Orientation
Roof
Plane
Materials
Color
Rooftop
Area
(Sq. Ft)
Suitable
Area
for PV
(Sq. Ft)
Suitable
Area for
Solar
Panels
(Sq. Ft)
Solar
Panels
Potentials
(kWh/day)
Solar
Roofs as
Panels
(kWh/day)
Solar
Roofs on
All
Suitable
Area
(kWh/day)
29
2230
W 20TH
ST
Cross
gable
North Shingle Dark grey 2288 175 175 15.9 13.0 13.0
30
2218
W 20TH
ST
Cross
gable
North Shingle Dark grey 2864 375 375 31.8 27.8 27.8
31
2214
W 20TH
ST
Cross
gable
North Shingle Grey 2798 275 275 26.5 20.4 20.4
32
2202
W 20TH
ST
Hip North Slate Dark grey 2906 0 0 0 0 0
33
2170
W 20TH
ST
Side
gable
North Shingle Dark grey 2441 0 0 0 0 0
34
2164
W 20TH
ST
Side
gable
North Shingle Grey 3433 0 0 0 0 0
35
2383
W 21ST
ST
Cross
gable
South Shingle Dark grey 2542 275 275 26.5 20.4 20.4
36
2357
W 21ST
ST
Cross
gable
South Shingle Dark grey 2606 475 475 42.4 35.2 35.2
37
2345
W 21ST
ST
Side
gable
South Shingle Dark grey 2237 275 150 15.9 11.1 20.4
2347
38
2307
W 21ST
ST
Side
gable
South Shingle Grey 2053 150 150 15.9 11.1 11.1
39
2301
W 21ST
ST
Cross
gable
South Shingle Dark grey 2107 250 250 21.2 18.6 18.6
40
2291
W 21ST
ST
Cross
gable
South Shingle Grey 2046 275 275 26.5 20.4 20.4
41
2283
W 21ST
ST
Cross
gable
South Shingle Grey 1733 350 350 31.8 26.0 26.0
42
2267
W 21ST
ST
Cross
gable
South Shingle Dark grey 2372 275 275 26.5 20.4 20.4
43
2261
W 21ST
ST
Cross
gable
South Shingle Dark grey 2498 325 325 26.5 24.1 24.1
44
2233
W 21ST
ST
Hip and
gable
South Shingle Dark grey 2924 225 225 21.2 16.7 16.7
45
2211
W 21ST
ST
Cross
gable
South Shingle Dark grey 2568 175 175 15.9 13.0 13.0
46
2179
W 21ST
ST
Side
gable
South Shingle Green 4070 100 100 10.6 7.4 7.4
47
2173
W 21ST
ST
N/A South
Red clay
tile
Red 2151 0 0 0 0 0
48
2167
W 21ST
ST
Side
gable
South Shingle Dark grey 3624 375 × × × 27.8
49
2388
W 21ST
ST
Cross
gable
North Shingle Dark grey 1943 200 200 15.9 14.8 14.8
50
2384
W 21ST
ST
Hip and
gable
North Shingle Dark grey 3331 275 275 26.5 20.4 20.4
51
2378
W 21ST
ST
Cross
gable
North Shingle Dark grey 3287 50 50 5.3 3.7 3.7
52
2372
W 21ST
ST
Side
gable
North Shingle Dark grey 3650 0 0 0 0 0
53 2366
2368
2370
W 21ST
ST
Gambrel North Shingle Dark grey 1952 400 400 37.1 29.7 29.7
54
2302
W 21ST
ST
Cross
gable
North Shingle Green 2932 225 225 21.2 16.7 16.7
55
2298

W 21ST
ST
Hip and
gable
North Shingle Dark grey 3364 150 150 15.9 11.1 11.1

53
# No.
Site
Address
Roof
Plane
Types
Orientation
Roof
Plane
Materials
Color
Rooftop
Area
(Sq. Ft)
Suitable
Area
for PV
(Sq. Ft)
Suitable
Area for
Solar
Panels
(Sq. Ft)
Solar
Panels
Potentials
(kWh/day)
Solar
Roofs as
Panels
(kWh/day)
Solar
Roofs on
All
Suitable
Area
(kWh/day)
56
2294
W 21ST
ST
Front
gable
North Shingle Dark grey 2733 250 250 21.2 18.6 18.6
57
2288
W 21ST
ST
Front
gable
North Shingle Dark grey 3280 150 150 15.9 11.1 11.1
58
2274
W 21ST
ST
Cross
gable
North Shingle Green 3465 175 175 15.9 13.0 13.0
59 2260
2256
2250
W 21ST
ST
Cross
gable
North Slate Dark grey 5483 300 300 26.5 22.3 22.3
Total (kWh/day)
826.8 673.7 803.2
Table 5.2: Analysis and calculation of solar roofs energy efficiency. Source: Table is produced by author.

Impacts Study
Within the calculation of fifty-nine of 127, forty-seven percent contributing candidates,
there are five circumstances to be noticed:
1) Seven properties have no access to solar resources according to the L.A.
County Solar Map, such as #18, #23, #32, etc. These properties are counted as “0” in the
table. As a result, there are only fifty-two properties that could use solar roofs;
2) Eight properties are not available to install solar panels due to visual
impacts, such as #3, #5, #6, #10, #11, counted as “x” in the table; (Figure 5.8)
3) There are some properties facing south where only a partial installation is
possible due to visual impacts, such as #14, #16, #39, etc. (Figure 5.9) For these
properties, the comparison still shows that the adoption of solar roofs can produce almost
the same energy as solar panels, even though the energy efficiency of solar roofs is
approximate seventy percent of solar panels.
4) In case of those properties that could install solar panels in all suitable
areas, the total energy production of solar roofs is less than the solar panels’, such as #1,
#2, #8, etc.
5) Properties that have suitable area for PV less than a hundred square feet
are actually not recommended to install solar energy system. Since the energy production
is so small the cost of installation cannot be justified, such as #1, #6, #12, etc.

54
Fig 5.8: Photos shows #10 and #11 properties with their solar maps. The solar maps indicate solar access on front
roofs. Yet, according to preservation plan that “solar panels should not be placed upon rooftops that are visible to the
general public”, it will be inappropriate to install solar panels on the front roofs of these two properties. Sources:
Photos by author, the solar maps are based on L.A. County Solar Map.

Fig 5.9: Photos show #14 property with its solar map on right. It will be inappropriate to install solar panels on the
front roof that could be viewed from the streets, but it may be possible to install solar panels on top of the front
gable. Sources: Photos by author, the solar maps are based on L.A. County Solar Map.

55
It should be noted that using the national average energy demand per household of 28.5
kWh per day (10,400 kWh per year divided by 365 days per year), only four of the properties can
completely cover their energy demand with solar (#28, #30, #36, and #41).
97
At 42.4 kWh per
day for panels / 35.2 kWh per day for solar roofs, Property #36 appears to have the highest solar
potential. Using the system installation cost and annual energy savings from the L.A. County
Solar Map report, the payback period (the time period where energy savings pays for installation
cost) is approximately sixteen years.
For all candidate properties in the Western Heights HPOZ, the total energy production of
solar roofs is approximate 803.2 kWh versus 826.8 kWh of solar panels per day. The energy
production turns out to be similar since solar panels are only installed at places that are
minimally viewed by the public, while solar roofs can be adopted in a larger area since it will
cause less visual impacts in a historic district. Even though the solar panels are more efficient, it
cannot be installed in most place that could be seen from the public view. Also, it should be
notice that the difference of energy production of solar panels and solar roofs will be narrower
with a smaller suitable area for PV. Neither solar panels nor solar roofs would be applicable for
those properties with incompatible roof colors.
The installation of solar roofs could be conducted by replacing only portions of historic
roofing materials, such as the rendering of a contributing property in the Western Heights HPOZ
with solar roofs in Figure 5.10. (Figure 5.10) Some companies like Tesla will encourage the
owner to replace the whole roof with parts of solar roofs and others of regular roof materials that
produced by the same company without solar cells inside for matching. The company
recommends using only thirty-five percent of solar roofs and fulfilling in the rest with non-solar
tiles.
98
It is another method to consider for conserving the feeling of a historic property while
improving the building envelope at the same time.
The exploration in the Western Heights HPOZ shows the possibility of adopting solar
roofs with fifty-two of 127, approximately forty-one percent contributing properties that could
use solar roofs. The outcome indicates that the energy production of solar roofs could be very
similar to solar panels for all suitable properties in the historic district. Still, the research is

97
Luke Richardson, “How Much Do Solar Panels Save?” Energysage, January 1, 2019,
https://news.energysage.com/much-solar-panels-save/.

56
conducted under the ideal situation with maximum energy production of both solar panels and
solar roofs. There is very limited data of solar roofs in a long term currently, and the outcome
may be different regarding regional conditions like solar angle as well as weather issues.
Moreover, the price of solar roofs could be twice to four times as expensive as solar panels
depending on different products.
99
It is still too high for the solar roofs to be popular in normal
residential properties right now.

Fig 5.10: The rendering of a contributing property with solar roofs in the Western Heights HPOZ. Source: Figure is
produced by author.

98
Hadley Keller, “What you should know before buying Tesla’s Solar Roof Tiles?”

99
“Solar Panel vs Solar Shingles,” Fixr, last modified on July 5, 2018, https://www.fixr.com/comparisons/solar-
panels-vs-solar-shingles.

57
Conclusion
In the era of sustainable conservation, the exploration of new technology enables heritage
conservation to have more methods for saving our buildings.
100
Although many preservation
design guidelines do encourage the adoption of renewable energy like solar systems on historic
properties, the gap still remains in conserving historic characters and adopting new building
systems like solar panels. While the new technology like solar roofs is gradually used in
architecture design currently, limited experiments are on historic property. The thesis tries to
explore the possibility of adopting solar roofs in a historic district. The Western Heights Historic
Preservation Overlay Zone (HPOZ) in Los Angeles is selected as a study plot. Besides the
appropriate physical conditions of the Western Heights HPOZ, the policies and rich context of
using solar energy in Los Angeles also encourage this HPOZ to be a good candidate for
installing solar roofs. The research has identified fifty-nine of 127, approximately forty-seven
percent of contributing properties that are compatible with solar roofs. Fifty-two of 127,
approximately forty-one percent, of contributing properties could actually produce enough
electricity to make solar roofs theoretically worthwhile. The result turns out solar roofs can
produce similar total energy as solar panels in all appropriate properties of a historic district.
A successful example of exploring solar roofs will no doubt inspire other HPOZs with
similar conditions such as Harvard Heights, which have 573 contributing properties and many of
them are in Craftsman styles with shingle roofs. Also, this will make a great impact on
sustainable development if it can bring other historic districts around the country in the
conversation.
Still, additional research is required. This thesis is narrow in scope with a hypothesis that
is based on an ideal maximum production of solar roofs. There is possibility that when it is
applied in a larger scale, the result will vary. Also, there is not sufficient data over a long term of
the solar roofs and all the performance information is provided by manufacturers. Especially for
red tile roofs, a compatible product is still hypothetical. Concern also remains in the high
expense of implementing solar roofs. Is a payback period of fifteen years or higher affordable for

100
The term of “advocates for heritage conservation” is giving credit to all people in this field rather than just
preservationists, including students, future professionals, academic and professionals, planners, architects, engineers,
scientists, etc.

58
homeowners in historic districts? Yet, it is likely that as production increases, it will reduce the
cost similarly to solar panels in 1980s.
The research is conducted under no preservation design guideline since there is a lack of
reference guideline for solar roofs. The preservation design guidelines of the City of Los Angeles
only mention the adoption of solar panels in a historic property, and there has no case of using
solar roofs in the city yet. Moreover, Los Angeles will not require historic property to go through
any preservation design review under the California Solar Act. It is suggested that preservation
design guideline to be evolved along with burgeoning technology like solar roofs. Questions like
whether it is available to install solar roofs on a visible front roof, whether it is appropriate to
replace historic roofing materials with solar roof tiles, and whether it is possible to install solar
roofs on a vertical shingled wall should be addressed. Ideally, a comprehensive strategy needs to
be charted out with clear goals for sustainability in a design guideline. Design reviews are
required in order to conserve historic integrity. This will organize the extent of detail which
should be provided with specific topics, such as solar systems installation, windows replacement,
etc.
101

To adopt solar roofs practically, besides preservation guidelines, there are more to
consider such as the preparation of installation with professionals, and installation technique with
the local energy companies. For cities like Los Angeles which has sufficient solar resources and
supportive policies, it will be better for encouraging sustainable conservation by proposing new
incentive programs for adopting solar roofs in historic properties.
It is expected that the advocates for heritage conservation are familiar with not only
preservation policies but also upgrading technology that can improve the performance of a
historic building. Besides solar roofs, there are other new technologies that could be adopted
within a historic property and needed to be explored. Bringing properties’ owners as well as
experts from other disciplines into the conversation will be another challenge for popularizing
new technology.
In 2018, the United States has experienced several extreme weather events. California
had its hottest summer with several massive fires, while parts of New England and New York

101
Nore Winter, “Developing ‘Green’ -Friendly Guidelines: Advice for Preservation Commissions,” Forum News,
Volume 17, Issue 4, December 1, 2010, https://forum.savingplaces.org/viewdocument/developing-green-friendly-
guidel.

59
have a historically snowy November.
102
In the circumstance of climate change, human beings
must do everything to preserve the limited resources for future generations. While heritage
conservation is already playing its role in sustainable development, in keeping with evolving
technology day by day like solar roofs will achieve more opportunities to make a building
greener. The exploration for adopting solar roofs within the Western Heights HPOZ in Los
Angeles tries to provide a reference of greening historic properties with new technology. The
goal of heritage conservation is never to stop the changing of our heritage but to manage change.
Historic buildings should be allowed to evolve for satisfying the ever-changing needs of our
environment. The greenest building is the one that has already been built.
103

102
Ian Livingston, “The Five Most Extreme Weather Events of 2018 in the United States,” the Washington Post,
December 31, 2018, https://www.washingtonpost.com/weather/2018/12/31/five-most-extreme-weather-events-
united-states/?noredirect=on&utm_term=.dc8a0bb9ae49.
103
Elefante, “The Greenest Building,” 26.

60
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http://www.thesolarvillage.com/content/news-post.cfm?news=628.
Richardson, Luck. “Tesla Soar Roof: Elon Musk’s solar roof tiles complete review.” Energysage,
January 3, 2019. https://news.energysage.com/tesla-solar-panel-roof-the-next-solar-shingles/.
Richardson, Luke. “How Much Do Solar Panels Save?” Energysage, January 1, 2019.
https://news.energysage.com/much-solar-panels-save/.
Ryan, Dylan. “Solar panels replaced tarmac on a road – here are the results.” the Conversation,
September 21, 2018. http://theconversation.com/solar-panels-replaced-tarmac-on-a-road-here-
are-the-results-103568.
Salt Lake City. A Preservation Handbook for Historic Residential Properties & Districts.
Accessed December 11, 2012.
San Francisco Planning. “Update: April 2013, Proposed Duboce Park Historic District.” April
2013.
http://default.sfplanning.org/Preservation/landmark_districts/proposed/duboce_park/Duboce_Par
k_Update_2013.pdf.
Simons, George, and McCabe, Joe. California Solar Resources: In support of the 2005
integrated energy policy report. Research and Development, Energy Research and Development
Division, California Energy Commission. April 2005.

63
Stein, Richard G. Architecture and Energy. New York: Anchor Press/Doubleday, Garden City,
1977).
Sweetser, Sarah M. “Preservation Briefs 4: Roofing for Historic Buildings.” Technical
Preservation Services, National Park Service, U.S. Department of the Interior. Accessed
February 1978. https://www.nps.gov/tps/how-to-preserve/briefs/4-roofing.htm#materials.
Tabb, Phillip James. “1970s: Solar Architecture” in The Greening of Architecture: A Critical
History and Survey of Contemporary Sustainable Architecture and Urban Design, edited by
Phillip James Tabb and A. Senem Deviren, 49-74. Ashgate Publishing, 2016.
Technical Preservation Service, National Park Service. “Secretary of the Interior’s Standards for
Rehabilitation.” https://www.nps.gov/tps/standards/rehabilitation.htm.
Thomason and Associates et al. Oklahoma City Historic Preservation Design & Sustainability
Standards and Guidelines. Oklahoma City, Oklahoma. Accessed July 2012.
Times Editorial Board, “Of Course California Should Require Solar Panels on New Homes.” Los
Angeles Times, May 11, 2018. https://www.latimes.com/opinion/editorials/la-ed-solar-new-
homes-20180511-story.html.
U.S. Department of Energy, North Carolina Solar Center, National Trust for Historic
Preservation. Installing Solar Panels on Historic Buildings: A Survey of the Regulatory
Environment. Prepared in August 2012. https://www.solsmart.org/media/installing-solar-panels-
on-historic-buildings_0812.pdf.
U.S. Department of Interior, National Park Service. National Register Bulletin: How to Apply the
National Register Criteria for Evaluation. 1997.
Winter, Nore. “Developing ‘Green’ -Friendly Guidelines: Advice for Preservation Commissions.”
Forum News, Volume 17, Issue 4 (December 1, 2010).
https://forum.savingplaces.org/viewdocument/developing-green-friendly-guidel.

64
Appendix A: Incorporating Solar Panels in a Rehabilitation Project

National Park Service
U.S. Department of the Interior
Technical Preservation Services
AL TERNATIVE ENERGY
Interpreting
The Secretary of the Interior’s Standards for Rehabilitation
ITS
NUMBER 52
Issue: Enhancing the energy efficiency of a historic building is important. T o that end, it is often possible to install features
such as solar panels and photovoltaic cells provided they are installed in a sensitive manner. Because these elements must be
positioned to take advantage of unobstructed sunlight, the roof of a historic structure is an obvious location. The roofline of a
historic building is often a distinctive feature. Therefore, the installation of solar panels should conform to guidance regarding
rooftop additions, i.e. that they be minimally visible, to avoid altering the historic character of the building. Historic buildings
with a flat roof or parapet can usually accommodate solar panels because the panels will be hidden, while properties with
a hipped or gabled roof are generally not good candidates for a rooftop solar installation. Solar panels on historic buildings
should not be visible from the public right of way such as nearby streets, sidewalks or other public spaces.
In circumstances where solar collectors are not placed on rooftops, they should only be positioned in limited or no-visibility
locations in secondary areas of the property . Vegetation or a compatible screen may also be an option to further reduce the
impact of these features on a historic property . For some historic buildings, it may not be possible to incorporate solar panels
and meet the Secretary of the Interior’s Standards for Rehabilitation.
Application 1 (Compatible treatment):
The rehabilitation of this mid-nineteenth
century mill incorporated a large, roof-
mounted photovoltaic installation.
Although the historic building does not
have a parapet wall at the roofline, the
height of the building and the arrangement
of the panels render the entire installation
invisible from the ground. It is important
to note that the panels are placed
horizontally . Had the panels been installed
with a vertical tilt, the angle required to maximize efficiency would have caused the panels to extend significantly higher
above the roof. Simply changing the direction in which the panels are tilted can affect their visibility and reduce their impact
on the character of the historic property .
Solar panels installed on the flat roof.
Because of the size of this historic mill, a large array of solar panels could be installed on
the flat roof without being seen from the ground.
Subject: Incorporating Solar Panels in a Rehabilitation Project
Applicable Standards: 2. Retention of Historic Character
9. Compatible Additions/Exterior Alterations
By placing the panels horizontally, the overall height
of the installation and its visibility is reduced.
solar panels
These bulletins are issued to explain preservation project decisions made by the U.S. Department of the Interior. The resulting determinations, based on the
Secretary of the Interior’s Standards for Rehabilitation, are not necessarily applicable beyond the unique facts and circumstances of each particular case.

Jenny Parker, Technical Preservation Services, National Park Service
Application 3 (Compatible treatment): The rehabilitation of this historic
post office incorporated solar panels as dual-function features: generation
of electricity and shading for south-facing windows. In this instance, the
southern elevation of the building is also a secondary elevation with limited
visibility from the public right of way . Additionally, because this area of the
building is immediately next to the post office’s loading dock, it has a more
utilitarian character than the primary facades and, therefore, can better
accommodate solar panels. Because the panels are in a suitable location at
the rear of the property and are appropriately sized to serve as awnings, they
do not affect the overall historic character of the property . Additionally, a
screen of tall plantings shields the solar panels from view from the front of
the building, further limiting their visibility .
August 2009, ITS Number 52
Application 2 (Incompatible treatment): During the rehabilitation of this late-nineteenth century commercial building, a
conspicuous rooftop monitor with prominent solar panels and skylights was constructed on the one-story structure. The size
and finish of this rooftop addition are incompatible with the historic character of the building. However, the building could
have accommodated both skylights and solar panels if they had been installed differently . An alternative design that could
have met the Standards would have included low-profile skylights and solar panels concealed behind the parapet wall.
Above: Shown from the rear of the property, these
solar panels serve a secondary function as awnings to
shade south-facing windows. Because of their location
at the back of the building immediately adjacent to a
loading dock, the installation of these panels does not
affect the historic character of the property.
Left: The solar panels are not visible from the front of
the building. Additionally, even if the vegetation were
removed, the installation would only be minimally
visible along an alley at the rear of a secondary side
elevation.
The addition of a large rooftop monitor featuring skylights on the front slope and solar panels on the rear slope is not compatible with the
historic character of this small, one-story commercial building.
Tall plantings shield solar panels from
view from the front of the building.

67
Appendix B: Apollo Tile II Solar Roofing System – CertainTeed Solar

CertainTeed Solar
APOLLO
®
TILE II
SOLAR ROOFING SYSTEM
Features and Benefits
Functional: The Apollo Tile II system functions as both a roof and a
solar array
Beautiful: An earth-toned custom frame combined with a profile that
matches flat concrete tiles provides a clean, integrated aesthetic
Efficient: Modules use 14 high-efficiency monocrystalline solar cells
Strong: Mechanical load rating of 250 lbs per square foot
Lightweight: Weighs significantly less than a tile roof eliminating the
need for structural review or reinforcement
Wind Resistant: Tested to the highest wind standards and backed by
a 110mph wind warranty
Water Shedding: Built-in water management features
Easy to Install: Open space under the modules and built-in wire clips
allow for easy wire management and installation
Aesthetic: Brown (frame); black (cells) on black (backsheet) provides
a greater aesthetic and visually blends with most concrete tile colors
A high-efficiency solar tile designed for
integration with most tile roofs.
See reverse for
product specifications
MADE IN USA
using foreign and domestic components
Each System Includes
63 watt, high-efficiency
monocrystalline modules
Waterproof and fire-resistant
underlayment membranes
Flashing accessories
Starter strip and wind clips
String inverter
Home run wiring
Monitoring system (optional)
CertainTeed Corporation
ROOFING • SIDING • TRIM • DECKING • RAILING • FENCE • GYPSUM • CEILINGS • INSULATION
20 Moores Road Malvern, Pa 19355 Professional: 800-233-8990 Consumer: 800-782-8777 certainteed.com
Standard Test Conditions: 25 C, 1kW/m
2
, AM 1.5
© 09/17 CertainTeed Corporation, Printed in the USA, Code No. PV-03-003
Dimensions Electrical Characteristics
Absolute Maximum Ratings
Warranty and Certifications Mechanical Characteristics
47
46
17
1
4
"
1
1
4
"
Maximum Power (Pmax) 63W
Maximum Power Voltage (Vmp) 7.27 V
Maximum Power Current (Imp) 8.67 A
Open Circuit Voltage (Voc) 9.28 V
Short Circuit Current (Isc) 9.25 A
Maximum System Voltage 600 V
Series Fuse Rating 15 A
Performance Tolerance +/- 3%
Conversion Efficiency 16%
Power Temp. Coefficient (Ptmp) -0.45%/˚C
Voltage Temp. Coefficient (Vtoc) -0.30%/˚C
Normal Operating Cell Temp. (NOCT) 53.5˚C
PTC Rating 54.1W
Exposed Area 46” x 13.25”
Weight 13 lbs (3.1 lbs per sq ft)
Cell Monocrystalline
No. of cells and connections 14 in series
Bypass Diode 1 per panel
Load Rating 250 lbs/sq ft
Wiring 14 AWG PV wire
Connectors MC4-EVO 3
Parameters Rating Unit
Operating Temperature -40 to +90 ˚C
Storage Temperature -40 to +90 ˚C
Dielectric Voltage Withstood 600 Max V-DC
Warranty 25 year limited power warranty
10 year limited product warranty
Certifications Certified to UL 1703 by CSA
UL 790 Class A Fire Rating
ASTM D3161 Class F
IEC 61215
California CEC Listed

70
Appendix C: Sunslate6 Installation Manual – Aesthetic Green Power

Aesthetic Green Power, Inc. Page 1 of 15 – REV. 3.1 06/25/13

1
Sunslates6
TM
Installation Manual
Table of Contents
1. About this Installation Manual ............................................................................................................................ 2
2. Sunslates6
TM
Specifications .................................................................................................................................. 2
2.1 Sunslates6
TM
Physical Specifications ........................................................................................................................ 2
2.2 Sunslates6
TM
Electrical Specifications ...................................................................................................................... 3
3. Sunslates6
TM
Storage and Handling ................................................................................................................... 3
4. Tools and Materials Used for Installing the Sunslates6
TM
Roof ................................................................ 4
5. Cutting Eternit Slates ............................................................................................................................................... 5
6. Preparing the Roof for Installation .................................................................................................................... 5
6.1 Waterproofing the Roof ................................................................................................................................................. 5
6.2 Vertical Battens ................................................................................................................................................................ 5
6.3 Horizontal Battens .......................................................................................................................................................... 6
6.4 Installing the First Row of Hooks ............................................................................................................................... 6
6.5 Marking Hook Locations ................................................................................................................................................ 6
6.6 Fixing the Starter Slates ................................................................................................................................................. 7
7. Sunslates6
TM
Installation Procedure ................................................................................................................. 8
7.1 Sunslates6
TM
Field (String) Electrical Characteristics ......................................................................................... 8
7.2 Sunslates6™ Cable Types ............................................................................................................................................... 8
7.2.1 Sunslates6™ Interconnect Cable (Slate-to-Slate Cable) ............................................................................................... 8
7.2.2 Sunslates6™ Twister Cable (Row-to-Row Cable) ........................................................................................................... 9
7.2.3 Sunslates6™ Bridge Cable ......................................................................................................................................................... 9
7.2.4 Sunslates6™ Field Cable ............................................................................................................................................................ 9
7.3 Sunslates6
TM
Connections ........................................................................................................................................... 10
7.4 Making Field Connections ........................................................................................................................................... 11
7.5 Installing the Sunslates6
TM
Modules ........................................................................................................................ 12
7.6 Row-Checking .................................................................................................................................................................. 13
7.6.1 Row-Checking Overview ........................................................................................................................................................ 13
7.6.2 Row-Checking Instructions ................................................................................................................................................... 13
7.6.3 Row-Checking Example .......................................................................................................................................................... 13
7.6.4 Finding the Location of a Fault ............................................................................................................................................ 14
7.7 Making Connections Under the Roof ....................................................................................................................... 14
7.8 Uninstalling and Replacing Sunslates6
TM
.............................................................................................................. 15

WESTERN U.S. AND
INTERNATIONAL SALES
EASTERN U.S. SALES MANUFACTURING
Joe Morrissey
P: 218-365-6283
jomo13@agreenpower.com

Rob Gardner
P: 804-937-3358
rgardner@agreenpower.com
7 Industry Street
Poughkeepsie, NY 12603
P: 845-486-4052
F: 845-486-4054

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Sunslates6
TM
Installation Manual
1. About this Installation Manual

Aesthetic Green Power provides these guidelines for the installation of Sunslates6
TM
PV roofing slates to assist
the applicator in creating an efficient and workman-like application. Although this manual provides details for typical
conditions encountered on slate applications, all application details are beyond the scope of this text. When
encountering any conditions not illustrated in this manual, please contact Aesthetic Green Power for assistance.
All materials utilized in the construction, including fasteners, flashing, felts and penetrations, should be selected
to provide the same life as the Sunslates6
TM
installation (50 year life-time expected). The installer must use all of the
electrical materials (cables, junction boxes, inverters etc.) specified in this manual. Artificially concentrated sunlight shall
not be directed on the module. Failure to conform to these installation guidelines will void the Aesthetic Green Power
and/or Eternit warranty.

2. Sunslates6
TM
Specifications

2.1 Sunslates6
TM
Physical Specifications

Sunslates6
TM
are a roofing material that use solar energy to produce electrical energy. Sunslates6
TM
are
composed of:
1. Solar Module
2. Connection Box
3. Eternit Fiber Cement Roofing Slate
4. Wire Clips

Figure 1 – Sunslates6
TM
Components and Dimensions

Exposed Surface 19-11/16” x 14-1/2” (50.0 cm x 36.8 cm)
Total Sunslates/ 100 ft
2
50 Sunslates/ 100 ft
2

Powered Sunslates/ 100 ft
2
45 Powered Sunslates/ 100 ft
2

Weight/ Sunslate 14.3 lbs. (6.49 kg)
Sunslate Weight/100 ft
2
715 lbs (324 kg)/ 100 ft
2

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Sunslates6
TM
Installation Manual
2.2 Sunslates6
TM
Electrical Specifications

The electrical characteristics are within ±5% of the indicated values of I
sc
, V
oc
and P
max
under Standard Test
Conditions (STC)
1
. Depending on ambient conditions, time of day, time of year, and shading, Sunslates6
TM
may produce
more current and/or voltage than reported at STC. Accordingly, the rated values of I
sc
and V
oc
should be multiplied by a
factor of 1.25 when determining component voltage ratings, conductor ampacities, fuse size and the size of controls
connected to the PV output.

The Sunslates6
TM
module consists of six 6” (156mm) mono-crystalline PV cells connected in series.

Note: All characteristics are at Standard Test Conditions (STC)

Model SS156GM
Power 23 Watts
I
SC
8.55 ADC
V
oc
3.76 VDC
I
MPP
8.07 ADC
V
MPP
2.85 VDC

This product adheres to UL Standard 1703 and is CEC listed. All module components rated for 600 VDC. Please see Section 7.1 for
limitations on series string voltage.

Roofing Material Fire Rating - Class A

3. Sunslates6
TM
Storage and Handling

Store Sunslates6
TM
and Eternit slates in a clean, dry, well ventilated area, protected from the weather. As soon
as the slates have been delivered and stored under cover, split the plastic wrap to allow for ventilation to prevent
excessive water condensation. If the slates should get wet in storage, efflorescence is likely to occur. Mild efflorescence
of the slates will usually disappear over a period of time. Severe efflorescence may require special treatment. Contact
the Technical Department at Eternit Inc. or Aesthetic Green Power for details.

Do not handle Sunslates6™ in rainy or wet weather conditions (water must not enter the connection box).

1
Standard Test Conditions (STC): 1000 W/m
2
irradiance, 25°C temperature, and AM 1.5 spectrum

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Sunslates6
TM
Installation Manual
4. Tools and Materials Used for Installing the Sunslates6
TM
Roof

Figure 2 – Sunslates6
TM
Cables

Figure 3 – Hardware and Tools

Starter Slates are installed under the first row of
Sunslates6™.

Main slates and half slates are optional for finishing the edges
and/or eaves of roof.
Figure 4 –Eternit Slates

1 Sunslates6
TM
Hook
2 Protection Shield
3 Connection Opener
1 Starter Slate 18-1/2” x 19-11/16” (47.0 cm x 50.0 cm)
2 Half Slate 33-1/8" x 9-13/16" (84.1 cm x 24.9 cm)
3 Main Slate 33-1/8” x 19-11/16” (84.1 cm x 50.0 cm)

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Sunslates6
TM
Installation Manual

No-Power (NP) Sunslates6™ are used for aesthetic purposes only.
There is no electrical performance from the NP Sunslates6™.

Figure 5 – NP Sunslates6
TM
(optional)

Other Materials (not provided by Aesthetic Green Power):
1. Ice and water shield (optional)
2. 30 lb. roofing felt
3. Metal flashing and drip edges
4. Wooden battens
a. 2x2 vertical battens
b. 1x4 horizontal battens
c. 1x8 horizontal starter batten
d. ½ x1 cant strip
5. 0.1205" x 2-1/2" galvanized steel nails or #10 2-1/2” galvanized steel wood screws
6. 0.1205” x 1-1/2” galvanized steel nails or #10 1-1/2” galvanized steel wood screws
7. Silicon adhesive (Recommended Shinetsu KE-45)

5. Cutting Eternit Slates

Eternit fiber cement slates can be cut and punched with a slater's hammer. For rapid and efficient cutting,
punching and notching, a portable slate cutting machine may be utilized. Interior cuts in the slate can be accomplished
with a pin punch and hammer. Individual slates can be faced, scored and snapped over a straight edge.

6. Preparing the Roof for Installation

Sunslates6
TM
are installed using the double overlap system provided by the Eternit, Inc. The double overlap
system is a method of cladding thin panels to fixed battens. This method of cladding is characterized by the fact that at
every point on the surface, there are at least two layers of slate. To get a good water and airtight seal, an underlayment
of roofing-felt, vertical battens and horizontal battens is necessary.

6.1 Waterproofing the Roof

Use one layer of 30 lb. felt. In some areas an underlayment of ice and water shield may be required or desired
as an upgrade. Use appropriate metal flashing, including drip edges where necessary.

6.2 Vertical Battens

Fix 2x2 battens to rafters, securing at not more than 24” on center using 0.1205" x 2-1/2" galvanized steel nails
or #10 2-1/2” galvanized steel wood screws.

1 NP Sunslates6
TM
33-1/8” x 19-11/16” (84.1 cm x 50.0 cm)
2 Left NP Sunslates6
TM
33-1/8" x 9-13/16" (84.1 cm x 24.9 cm)
3 Right NP Sunslates6
TM
33-1/8" x 9-13/16" (84.1 cm x 24.9 cm)

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Sunslates6
TM
Installation Manual
6.3 Horizontal Battens

A 1x8 horizontal starter batten and a ½x1 cant strip are required for the first row. 1x4 battens are used for the
remainder of the horizontal battens. The bottom edge of the first 1x4 batten should measure 16-1/2” (41.9cm) from the
bottom edge of the starter batten. Fix the remaining 1x4 battens to conform to chalk lines securing at 14-1/2” (36.8cm)
on center. Use 0.1205” x 1-1/2” galvanized steel nails or #10 1-1/2” galvanized steel wood screws (two offset
nails/screws per intersection). Please refer to the diagram below (Figure 6).

Figure 6 – Batten Layout

6.4 Installing the First Row of Hooks

Sunslates6
TM
are mounted on the roof using hooks. DO NOT nail or screw Sunslates6
TM
into the roof. Only
starter slates, main slates, half slates, and NP Sunslates6
TM
may be nailed or screwed to the battens.
Place the first hook in the bottom row at 9-7/8” (25.1cm) from the edge of the first vertical batten and 4-1/2”
(11.4cm) from the bottom edge of the starter batten (see Figure 7). To attach the hook, nail it directly into the starter
batten. Use a chalk cord and water level to attach the remainder of the hooks in the first row at 20-1/16” (51cm)
apart.
2
It is extremely important that the first row hooks are aligned and spaced evenly.

6.5 Marking Hook Locations

After it is insured that the first row hooks are in place, a series of chalk lines are used to mark the locations
of the remainder of the hooks on the roof. Follow these steps carefully (refer to Figure 7):

1. Measuring from the starter hook line, create horizontal chalk lines spaced at 14-1/2” (36.8cm) up the roof
slope.
2. Starting from each hook in the first row, create vertical chalk lines, marking the horizontal battens at every
second intersection with the horizontal chalk lines (i.e. every 29” up the roof).
3. Create diagonal chalk lines that connect the hooks in the 1
st
, 3
rd
, 5
th
rows etc. Mark the locations on the 2
nd
,
4
th
, 6
th
etc. row battens where the diagonal chalk lines intersect the horizontal chalk lines.

2
The hook-to-hook distance may be decreased slightly to 20” (50.8cm). The spacing that is chosen for the first row must be used consistently
for the remainder of the roof. The first row of hooks and starter slates are the most important to ensure an aligned roof.

Aesthetic Green Power, Inc. Page 7 of 15 – REV. 3.1 06/25/13

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Sunslates6
TM
Installation Manual

Figure 7 – Hook Locations using Chalk Lines

6.6 Fixing the Starter Slates

The starter slates are installed under the first row of Sunslates6
TM
and are fastened to the starter batten. One
starter slate must be cut in half (Section 5) for use as the first and last starter slates in the row. Allow each starter slate to
overhang the bottom edge of the starter batten by ½” (1.3cm) and center between the first row hooks. Secure with two
nails into the starter batten (Figure 8).

Figure 8 –Starter Slates

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Sunslates6
TM
Installation Manual
7. Sunslates6
TM
Installation Procedure

7.1 Sunslates6
TM
Field (String) Electrical Characteristics

The Sunslates6
TM
array is divided into sections called “fields” (aka. “strings”). All fields in the array contain an
equal number of Sunslates6
TM
connected in series.
Although Sunslates6
TM
are rated for 600VDC, DO NOT connect more than 36 Sunslates6
TM
in series on the roof.
If higher voltage is desired, a code compliant combiner box may be used to connect fields, up to a maximum of 60
Sunslates6
TM
in series. All connections under the roof are to be performed by a trained and licensed electrical contractor.
When calculating the operating voltage please refer to the inverter/charge controller input voltage specifications.
Aesthetic Green Power is not responsible for design inconsistencies.

Maximum Series String Electrical Characteristics
(36 Sunslates6
TM
in Series)

Note: All characteristics are at Standard Test Conditions (STC)

Power 828 Watts
I
SC
8.55 ADC
V
oc
135.4 VDC
I
MPP
8.07 ADC
V
MPP
102.6 VDC
Series fuse rating: 15 Amps

For battery charging applications we recommend the following configuration:

12 Volt Systems 24 Volt Systems 48 Volt Systems
6 Sunslates6
TM
in series 12 Sunslates6
TM
in series 24 Sunslates6
TM
in series

Aesthetic Green Power recommends that all system components, including batteries and electronic devices, are listed by
a nationally recognized laboratory.

7.2 Sunslates6™ Cable Types

All cables for the installation (Interconnect cable, Twister Cable, Bridge Cable, and Field Cable) supplied by Aesthetic
Green Power are 13 AWG, type UF (UL), sunlight resistant, 90°C, 600 Volts.

7.2.1 Sunslates6™ Interconnect Cable (Slate-to-Slate Cable)

The Interconnect Cable connects Sunslates6™ in the same
row in series.

Figure 9 – Interconnect Cable

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Sunslates6
TM
Installation Manual
7.2.2 Sunslates6™ Twister Cable (Row-to-Row Cable)

The Twister Cable is used to connect Sunslates6™ in
different rows in series. The Twister Cable is used when the
field spans more than one row.

Figure 10 – Twister Cable

7.2.3 Sunslates6™ Bridge Cable

The purpose of the bridge cable is to route one terminal of the
field to the opposite end of the field. In this manner, both the
positive (+) and negative (-) terminals of the field are located
at the same end of the field.

Figure 11 – Bridge Cable

7.2.4 Sunslates6™ Field Cable

The Field Cable is placed at the beginning of the field. The
field cable has two wires: a positive (+) terminal and a
negative (-) terminal for the field.

Custom length field cables may be purchased if required.

Figure 12 – Field Cable

Aesthetic Green Power, Inc. Page 10 of 15 – REV. 3.1 06/25/13

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Sunslates6
TM
Installation Manual
7.3 Sunslates6
TM
Connections

In order to connect the Sunslates6™ cables to the connection box, follow these instructions:

Open connection box:

Place the tool in the connection box (1).

Turn the tool 90 degrees (2).

Insert cable:

Place the cable in the connection box (3).

Be sure to fully seat connector. Gasket at base of pins
must snap in.

Close connection box:

Turn the tool 90 degrees (4).

Remove the tool (5).

Apply adhesive
*
:

Clean the box surface (acetone or alcohol may be used).

Apply silicone sealant on the locations shown.

Use safety and installation instructions of the silicone
sealant.

Attach protection shield
*
:

Place the protection shield over the connection box and
apply pressure (7).

The two side clips of the shield must snap under the
connection plugs.

*
Performed AFTER row-checking (Section 7.6)

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Sunslates6
TM
Installation Manual
7.4 Making Field Connections

Each field begins with a Field Cable and ends with a Bridge Cable (Figure 13). When installing the field,
ALWAYS start at the end with the Field Cable (which goes through the roof into the building) and work your way to the
end of the string. The Bridge Cable should be the last cable in the field to be installed. Use Interconnect Cables to
connect modules in the same row. If the field spans more than 1 row, use a Twister Cable to connect one row to the next
(Figure 14).

Figure 13 – Sunslates6
TM
Field

Figure 14 - Sunslates6
TM
Field Using Twister Cable

Aesthetic Green Power, Inc. Page 12 of 15 – REV. 3.1 06/25/13

12
Sunslates6
TM
Installation Manual
7.5 Installing the Sunslates6
TM
Modules

To install the first row of Sunslates6™, simply slide the notch at the bottom edge of the Sunslates6™ onto the
hook. Ensure that each hook is straight and that the marked location for the hook in the next row is visible between the
slates. As each Sunslates6™ is installed, make the connections as outlined in Sections 7.3 and 7.4.
Once the first row has been installed and row-checking has been performed (Section 7.6), the next row can be
installed. As subsequent rows of Sunslates6™ are installed, nail the hooks into the pre-marked locations (Section 6.5)
and follow the same procedure used for the first row of Sunslates6™.

Figure 15 – First Row Profile

1.Starter batten (1x8)
2. Plywood (5/8” or 1/2” CDX)
3. Horizontal Batten (1x4)
4. Vertical Batten (2x2)
5. Cant Strip (1/2x1)
6. Drip Edges

F = 14-1/2” (36.8cm)

Aesthetic Green Power, Inc. Page 13 of 15 – REV. 3.1 06/25/13

13
Sunslates6
TM
Installation Manual
7.6 Row-Checking

7.6.1 Row-Checking Overview

When installing Sunslates6™, the most common error made is that the Sunslates6™ connection box is not in a
closed position. The installer must perform row-checking for each row to insure that the Sunslates6™ connection boxes
are closed and making electrical contact.
Row-checking is performed by measuring the open circuit voltage of each field. Make sure that row-checking is
performed BEFORE the row is covered by the next row of Sunslates6™. This will prevent any difficulties with having to
un-install portions of the roof to fix a connection box that was not properly closed.
If a field spans more than one row, it will be necessary to temporarily install a Bridge Cable at the end of the
uncompleted field to perform the voltage measurement. Once these connections have been verified, the protection
shields can be attached and the next row of Sunslates6™ may be installed.

7.6.2 Row-Checking Instructions

1. First, the expected open circuit voltage (V
oc
) of one Sunslates6™ module at current ambient conditions must be
determined. Use a simple DC voltmeter to measure the V
oc
of a single Sunslates6™ module. To make the
measurement, open the connection box terminals (Section 7.3), insert the voltmeter probes, and then close the
connection box terminals (Figure 16). Measure the V
oc
of a few additional Sunslates6™ modules and average
the results. The average V
oc
should be approximately 3.8 V, but may vary depending on ambient conditions.

Figure 16 – Measuring Open Circuit Voltage

2. Determine the expected V
oc
of the field by multiplying the expected V
oc
of one Sunslates6™ module by the
number of Sunslates6™ in the field.
3. Measure the V
oc
of the field using the DC voltmeter. Ensure that the field measures a V
oc
that varies from the
expected V
oc
by no greater than 3 VDC.

Shadows from instruments or cables over the Sunslates6
TM
will cause the voltage to drop; be sure that there are no
shadows when testing the field.

7.6.3 Row-Checking Example

If the field is composed of 20 Sunslates6™ in series and the expected V
oc
of one Sunslates6™ module is 3.8 VDC:

V
oc
(field) = (3.8 VDC) x (20 Sunslates6™) = 76 VDC

If the field measures lower than 73 VDC or does not measure any V
oc
, it is likely one or more Sunslates6™ modules are
poorly connected and the installer must go back and check the field for:
1) A connection box which is not fully closed or
2) A faulty Sunslates6™ module.

Aesthetic Green Power, Inc. Page 14 of 15 – REV. 3.1 06/25/13

14
Sunslates6
TM
Installation Manual
7.6.4 Finding the Location of a Fault

To find the location of the fault, the easiest way is to divide the faulty field into sections. For a field of 20 Sunslates6™,
divide the field into 2 sections of 10 Sunslates6™. Check each section separately using a Bridge Cable to temporarily
close the circuit. Once it has been determined which of the two sections is faulty, that section can again be divided into 2
more sections (i.e. into 2 sections of 5 Sunslates6™). Continuing in this way, keep dividing the section until it is
determined which individual Sunslates6™ is at fault. The expected V
oc
must be recalculated each time the number of
Sunslates6™ changes. For example, if the expected V
oc
of one Sunslates6™ module is 3.8 VDC:

20 Sunslates6™ V
oc
= 76 VDC 10 Sunslates6™ V
oc
= 38 VDC

5 Sunslates6™ V
oc
= 19 VDC 3 Sunslates6™ V
oc
= 11.4 VDC

2 Sunslates6™ V
oc
= 7.6 VDC 1 Sunslates6™ V
oc
= 3.8 VDC

7.7 Making Connections Under the Roof

*The information below is provided as a guideline. Please refer to NEC 690 for the most up-to-date electrical wiring
requirements*

After row-checking has been completed, the field cable is then inserted through a hole (min ∅ 0.5”) in the roof.
The field cable must be secured with a cable clamp, for strain relief, onto the nearest 2x2 vertical batten. From here, the
electrician will make the connections under the roof (in the building). The field cable must be connected to a junction box
(via terminal strips, 10A) through standard MC (metal-clad) cable or EMT (electrical metallic tubing).
The junction box is connected to the inverter using home run cables through standard MC (metal-clad) cable or
EMT (electrical metallic tubing) (refer to NEC 690 for cable requirements). Make sure that the DC positive goes to the
positive terminal of the inverter and the DC negative goes to the negative terminal of the inverter. Test the field polarity
prior to making any connection.

Figure 17 – Routing the Field Cable

Seal the hole in the roof from the inside with fire stop expanding foam or silicon seal. The fire stop sealant shall be
a one-part, neutral curing silicone sealant. The sealant shall be completely water resistant and shall contain no solvents
or inorganic fibers of any kind. The through-penetration fire stop sealant shall allow movement of ±25% and shall be UL
Classified and/or FM Systems Approved and tested to the requirements of ASTM E814 (UL1479). The recommended
silicon sealant is Pensil® 300 (PEN300).

Aesthetic Green Power, Inc. Page 15 of 15 – REV. 3.1 06/25/13

15
Sunslates6
TM
Installation Manual
7.8 Uninstalling and Replacing Sunslates6
TM

*Before disconnecting the Sunslates6™, the DC disconnect switch at the inverter must be in OFF position*

Bend the hook that holds the slate at the bottom with a roofer’s hammer, and then slide the slate down until you
see the Sunslates6™ connection box. Open the connectors and pull out the Interconnect Cables; the Sunslates6™ will
then slide down and can be removed. Replace with a new Sunslates6™ by sliding it up between the slates and then
connecting the Interconnect Cables. The hook must then be bent back into place to secure the slate.

WESTERN U.S. AND
INTERNATIONAL SALES
EASTERN U.S. SALES MANUFACTURING
Joe Morrissey
P: 218-365-6283
jomo13@agreenpower.com

Rob Gardner
P: 804-937-3358
rgardner@agreenpower.com
7 Industry Street
Poughkeepsie, NY 12603
P: 845-486-4052
F: 845-486-4054

86
Appendix D: An Example of the Solar Roof Report

Local Property Map with Solar Potential
Property Information
Property Address
Parcel Number
Utility Name
Total Roof Area (squre feet)
Area Suitable for Solar (square feet)
Solar PV Potential Information
Typical panel efficiency:
Solar PV System size (kW DC)
1kw system = 1,490 kWh/year Figures represent the use of all suitable area. 1 kWh = 3 hours of TV, 10 hours of 100w lightbulb
Electricity output (kWh/year)
18.1% 13.1%
Electricity savings ($/year)
(See back for details)
Carbon Savings (lbs/year)
Solar PV Costs and Incentives
These figures are best estimates which vary by roof type, system size, and installer.
Federal Tax Credit
(30% tax credit)
Final cost ($/watt)
http://www.gosolarcalifornia.ca.gov/consumers/taxcredits.php
(LA County Assessor)
(LA County Assessor)
(2008 LA County Building outline data)
(2006 LA County Solar Model - see back for details)
2388 21ST ST, LOS ANGELES CA
5073-026-013
Los Angeles Department of Water & Power
1,943 Sq. Ft.
200 Sq. Ft.
Up to 3 kW DC
5,010 kWh/year
Up to $651 /year
3,627 lbs/year
Up to 2 kW DC
3,626 kWh/year
Up to $471 /year
2,625 lbs/year
$4.50 /watt
-$1.35 /watt
$3.15 /watt
LA COUNTY SOLAR MAP (http://egisgcx.isd.lacounty.gov/cos/m/?viewer=solarmap)
SOLAR ROOFTOP POTENTIAL REPORT
2388 21ST ST, LOS ANGELES CA
PROPERTY ADDRESS:
https://www.ladwp.com/ladwp/faces/ladwp/commercial/c-gogreen/c-gg-installsolar
Click for Solar Map
(Assessor map)
Initial system cost ($/watt) More Info:
Printed: 3/10/2019 3:11:42 AM
Solar Water Heating
Figures represent the use of all suitable area.
Solar water heating potential (therms)
Gas savings ($/year)
Carbon savings (lbs/year)
Other Information
How Los Angeles County estimated this property's solar potential:
The LA County Solar Rooftop Planning Tool is based on solar radiation calculated every 5 feet for over 3,000 square
miles. This model includes the effects of roof pitch, orientation, and shading from surrounding structures and trees. It
was created through a Geographic Information Systems (GIS) analysis of Light Detection and Ranging (LiDAR)
elevation information
Total Roof Area From the 2008 LA County building dataset.
Roof area in square feet where average daily raw insolation > 4.04 kWh.
Solar PV Potential (kW DC) Area in square feet is converted to area in square meters (divide area 10.76391), and multiplied by 0.181
(for 18.1% efficiency) to determine system size in kW (DC) or by .131 (for 13.1% efficiency). Note that
these panels are representative, not recommendations.
Potential Annual Output (kwH/year) 1,490 kWh per year per solar PV Potential kW (DC). This is calculated by multiplying solar PV
potential in kW by 5.3 hours of generation per day and a 77% de-rate factor which take into
consideration electrical losses and other environmental factors like soiling. (Solar PV Potential x
365 days x 5.3 hours/day x 0.77 efficiency).
Potential Cost Savings ($/kWh)
Potential Annual CO2 Savings The carbon dioxide emission reductions for Southern California are 724 lbs of carbon dioxide
reduced for every MWh of solar electricity (CA Climate Action Registry General Reporting
Protocol, Version 3.1, Table C.2 - CO2 Emission) and CO2 emissions for natural gas (11.7
lbs/CO2/therm).
Gas Savings Therms per year multiplied by the SoCal Gas baseline gas rate per therm. A typical LA County
household uses 200 therms/year to heat water.
More Details http://solarmap.lacounty.gov/content/map/estimate.htm
600 Therms/Year
$474 /Year
8 lbs CO2/Year
A typical LA County household uses 200 therms/year to heat water
Area Suitable for Solar
$0.130 Los Angeles Department of Water & Power
Disclaimer: The tools in the Solar Map application are for estimating purposes only and subject to changes due to latest technologies, efficiencies,
and current data tool was developed or updated.
Printed: 3/10/2019 3:11:42 AM

89
Appendix E: Western Heights HPOZ Preservation Plan

City of Los Angeles
Adopted December 9, 2010
Western Heights HPOZ
Preservation
Plan

3
Preservation Plan
Table of Contents
Chapter 1: 5
Mission Statement
Chapter 2: 7
Goals & Objectives
Chapter 3: 9
Function of the Plan
Chapter 4: 17
Context Statment
Chapter 5: 25
Historic Resources Survey
Chapter 6: 27
Architectural Styles
Chapter 7 45
Residential Rehabilitation
Chapter 8: 65
Residential Additions
Chapter 9: 69
Residential In-fi ll
Chapter 10: 79
Public Realm
Chapter 11: 83
Defi nitions
4
5
Preservation Plan
F
acilitate the vitality of the district as a livable and sustainable
neighborhood through the restoration, preservation and
enhancement of structures, landscaping and natural features.
Chapter 1 Mission Statement
6
7
Preservation Plan
Chapter 2 Goals & Objectives
Goal 1 Preserve The Historic Character Of The Community
Objective 1.1 Safeguard the character of historic buildings and sites
Objective 1.2 Recognize and protect the historic streetscape
and development patterns
Objective 1.3 Ensure rehabilitation and new construction within the district complements the his-
toric fabric
Objective 1.4 Recognize that the preservation of the character of the district as a whole takes prece-
dence over the treatment of individual structures or sites.
Goal 2 Preserve The Historic Streetscape
Objective 2.1 Encourage and maintain traditional front yards.
Objective 2.2 Promote retention of historic landscape features
Goal 3 Preserve The Historic Appearance Of Residential Structures
Objective 3.1 Encourage retention of signifi cant architectural features
Goal 4 Achieve Widespread Public Awareness And Involvement In Historic Preservation
Throughout The HPOZ
Objective 4.1 Keep local residents, the preservation community, the general public and decision
makers informed about historic preservation issues and initiatives, and facilitate public access to this
information
Objective 4.2 Promote public participation in the HPOZ review process
Objective 4.3 Inform the public and preservation community about effective preservation techniques
and resources
Goal 5 Assist In The Effective Implementation Of The HPOZ Ordinance
Objective 5.1 Facilitate fair and impartial decisions regarding proposed projects with this Plan
Objective 5.2 Educate and inform the HPOZ community about the community benefi ts of historic
preservation
Objective 5.3 Create a resource of information on architectural styles found within the neighborhood
Objective 5.4 Encourage citizen involvement and participation in
the review process
8
9
Preservation Plan
Chapter 3 Function of the Plan
3.1 Role of the Preservation Plan
This Preservation Plan is a City Planning Commission approved
document which governs the Western Heights Historic Preservation
Overlay Zone (HPOZ). The plan, through its design guidelines, as well
as its goals and objectives, aims to create a clear and predictable set of
expectations as to the design and review of proposed projects within
the district. This plan has been prepared specifi cally for this HPOZ
to clarify and elaborate upon the review criteria established under the
HPOZ Ordinance.
The Western Heights HPOZ Preservation Plan serves as an
implementation tool of the South Los Angeles and West Adams-
Baldwin Hills-Leimert Park Community Plans (both parts of the land
use element of the City’s General Plan). HPOZs are one of many types
of overlay districts, policies, and programs that serve to advance the
goals and objectives of the Community Plan.
The Western Heights Preservation Plan outlines design guidelines
for the rehabilitation and restoration of structures, natural features,
landscape and the public realm including streets, parks, street trees,
and other types of development within the HPOZ. The Preservation
Plan also serves as an educational tool for both existing and potential
property owners, residents, and investors and will be used by the general
public to learn more about the HPOZ. The Preservation Plan is to be
made available to property owners and residents within the HPOZ, and
should be reviewed by the Board every two years.
The Western Heights HPOZ Board will make recommendations and
decisions based on this document. Similarly, the Department of City
Planning will use this document as the basis for its determinations.
The Preservation Plan articulates the community’s vision and goals
regarding the HPOZ by setting clear guidelines for the development
of properties within the district. The Preservation Plan will serve
as a resource for property owners planning repairs or alterations as
an educational tool for both existing and potential property owners,
residents, and investors, and will also be used by the general public to
learn more about the City of Los Angeles and its unique neighborhoods.
3.2 Role of the HPOZ Board
All HPOZs in the City are administered by a local board comprised
of fi ve members appointed by the Mayor, the Councilmember, the
Cultural Heritage Commission and the Board at-large. These members
are appointed because they have expertise in historic preservation,
architecture, real estate and construction. The HPOZ Ordinance
requires that the HPOZ Board make all decisions related to maintenance,
repair, restoration and minor alterations to a property (work defi ned as
“Conforming Work”) and that the HPOZ Board serve as an advisory
body to the Department of City Planning related to new construction,
large additions and major alterations or rehabilitation projects. In
10
addition to their role as a decision making body, the HPOZ Board is
an educational resource with unique experience and expertise both in
historic preservation practices and in the rich history of this culturally
and architecturally signifi cant neighborhood.
In an effort to encourage property owners to comply with the
Preservation Plan guidelines and facilitate a streamlined review of
simple maintenance, repair and restoration projects, review of many
types of Conforming Work projects have been delegated by the HPOZ
Board to the Director of Planning. For many types of work applicants
can contact Planning staff and have their projects reviewed once the
appropriate application materials have been received instead of being
agendized for an HPOZ Board meeting. However, most types of work
on a property that involve a discernable change to the structure or site
will require HPOZ Board review. The list of projects that are delegated
to the Director of Planning for decision is provided in Section 3.5 below.
3.3 Organization of the Preservation Plan
Each Preservation Plan is required to contain seven elements: The
Mission Statement, Goals and Objectives, Function of the Plan, the
Context Statement, the Historic Resources Survey, Design Guidelines,
and the Preservation Incentives/Adaptive reuse policies located in the
Appendix.
Chapter 1 - Mission Statement: Establishes the community’s vision
for the Preservation Plan.
Chapter 2 - Goals and Objectives: States the goals for this plan and
offers specifi c programs or actions as the means to accomplish these
goals.
Chapter 3 - Function of the Plan: Reviews the role, organization,
and process of the Preservation Plan.
Chapter 4 - Context Statement: Outlines the history and signifi cance
of the community’s development.
Chapter 5 - Historic Resources Survey: Identifi es all Contributing
and Non-Contributing structures and includes Contributing
landscaping, natural features and sites, and vacant lots.
Chapter 6 - Architectural Styles: Provides an explanation of
architectural styles and building types that are relevant to the
neighborhood.
Chapter 7 - Residential Rehabilitation: Provides guidelines related
to the maintenance, repair and minor rehabilitation of existing sites
and structures.
Chapter 8: Residential Additions: Provides guidelines related to
additions and secondary structures.
11
Preservation Plan
Chapter 9: Residential In-fi ll: Provides guidelines for building new
residential structures in an HPOZ.
Chapter 10: Public Realm: Provides guidelines related to public
spaces, parks and streets.
Chapter 11: Defi nitions: Provides defi nitions for the various technical
and architectural terms used throughout this document.
An appendix of other useful information is found at the back of this
Plan. This appendix includes a compilation of preservation incentives
and adaptive reuse policies, process charts, and the HPOZ Ordinance.
3.4 HPOZ Process Overview
The Historic Preservation Overlay Zone has different review processes
for different types of project review within the HPOZ. For more
information on which review type is appropriate for a certain project,
contact staff at the Department of City Planning.
Certifi cate of Appropriateness: A Certifi cate of Appropriateness
(COA) is required when signifi cant work is proposed for a Contributing
element in the HPOZ. A COA requires that a formal application be
fi led with the Department of City Planning. The HPOZ Board will
conduct a public hearing and submit a recommendation to the Director
of Planning, who will also consider input from the Cultural Heritage
Commission regarding the project.
Certifi cate of Compatibility: A Certifi cate of Compatibility (CCMP)
is required for the review of new construction on vacant lots or on lots
where a Non-contributor is proposed for demolition. A CCMP also
requires that a formal application be fi led with the Department of City
Planning. The HPOZ Board will conduct a public hearing and submit a
recommendation to the Director of Planning.
Conforming Work on Contributing Elements: Conforming Work
on a Contributing Element (CWC) is a more expedient review process
limited to restoration, demolition in response to a natural disaster,
maintenance and repair, and minor alterations that do not result in a
discernable change to the character-defi ning features on a structure.
Some CWC projects may be simply reviewed by Planning staff while
others will require review by the HPOZ Board; see Section 3.5 for more
information.
Conforming Work on Non-Contributing Elements: Conforming
Work on a Non-contributing Element (CWNC) is a review process for
work on Non-contributing properties that does not involve demolition of
a structure or construction of a new building on a vacant lot.
12
3.5 Exemptions
As instructed by the City Planning Commission, and City Council
(notwithstanding LAMC 12.20.3 to the contrary), the following types
of work are exempt from HPOZ review in the Western Heights HPOZ
(unless the work is located in the public right-of-way).
1. Interior alterations that do not result in a change to an exterior
feature;
2. The correction of Emergency or Hazardous conditions where a City
enforcement agency has determined that such conditions currently
exist and they must be corrected in the interest of public health,
safety and welfare. When feasible, the City agencies should consult
with the Planning Department on how to correct the hazardous
conditions consistent with the Preservation Plan;
3. Department of Public Works improvements where the Director fi nds
that a) The certifi ed Historic Resources Survey for the Preservation
Zone does not identify any Contributing Elements located within
the Right-of-Way and/or where the Right-of-Way is not specifi cally
addressed in the Preservation Plan; and b) Where the Department
of Public Works has completed a CEQA review of the proposed
improvement and the review has determined that the work is exempt
from CEQA, or will have no potentially signifi cant environmental
impacts (the HPOZ Board shall be notifi ed of such Projects, given a
Project description and an opportunity to comment);
4. Alterations to City Historic-Cultural Monuments and properties
under an approved Historical Property (Mills Act) Contract;
5. Work specifi cally authorized by a Historical Property Contract
approved by the City Council;
6. Rear yard (non-corner lots only) landscape/hardscape work that is
not visible from the street and that does not involve the removal of a
mature tree or a feature identifi ed in the historic resources survey;
7. Landscape work in front and side yards, not including: hardscape
work; installation of artifi cial turf; installation of fences or hedges;
planting of new trees; removal/pruning of any mature tree or work on
any feature identifi ed in the historic resources survey. Additionally,
landscapes where more than 40% of the front yard area is bereft of
planting are not exempt;
8. Installation or repair of in-ground swimming pools located in the
rear yard on non-corner lots;
9. Rear yard grading and earth work on Non-Hillside lots as determined
by the LAMC;
13
Preservation Plan
10. Installation and expansion of rear patios or decks that are no higher
than 5 feet above fi nish grade (including railings), not including
balconies, roof structures, trellises, gazebos or other similar
structures;
11. Installation, replacement or repair of mechanical equipment that is
located within the rear yard area;
12. Installation of lighting devices on facades that are not visible from
the street;
13. Exterior painting with no change from existing paint colors;
14. Maintenance and repair of existing foundations with no physical
change to the exterior;
15. Removal of security grilles and/or gates that were installed outside
of the Period of Signifi cance;
16. Removal of fences that were installed outside of the Period of
Signifi cance.
3.6 Delegated to the Director of Planning
In the Western Heights HPOZ, the review of the following types of
work is delegated to the Director of Planning and therefore shall not
require review by the HPOZ Board, but the HPOZ Board shall receive
a notice of the Director of Planning’s action or decision. The Director
of Planning shall utilize the Design Guidelines contained within this
Preservation Plan to determine whether the proposed project may be
found to be Conforming Work. Projects that do not comply with the
Design Guidelines, or that involve an existing enforcement case with
the Department of Building and Safety or the Housing Department, or
otherwise involve a request for approval of work that was performed
without appropriate approval, shall be brought before the HPOZ Board
for review and consideration, either as Conforming Work or as requiring
a Certifi cate of Appropriateness or Certifi cate of Compatibility.
1. Pruning of mature trees and the installation of new trees.
2. In-kind hardscape replacement within the front yard (driveway,
walkways, etc) that does not expand the hardscape footprint;
3. Exterior painting involving new paint colors and not including paint
applied to previously unpainted surfaces such as stone, masonry or
stained wood;
4. Ordinary maintenance and repair (including in-kind replacement)
to correct deterioration or decay, that does not involve a change in
the existing design, materials or exterior paint color;
5. In-kind replacement of asphalt roof shingles, or repairs to tile, slate
or other similar roofs where existing roof materials are re-used
14
and repairs are made to underlying roof structure, and where roof
details such as fascia, eaves and brackets will not be affected.
6. Removal of non-historic stucco, asbestos shingles, vinyl siding or
other similar materials, when underlying historic materials can be
repaired or replaced in-kind. Where evidence of original materials
is unclear, work shall be deferred to the HPOZ Board for review;
7. Installation of screen doors or windows that do not obscure the
actual door or window;
8. Replacement of non-original windows with windows that match
the originals, when examples of original windows still exist on the
structure;
9. Construction or installation of ramps, railings, lifts, etc., on any
non-visible elevation of a building intended to allow for accessibility;
10. Any alterations to a structure that is identifi ed as Non-Contributing
in the Historic Resources Survey, not including additions, new
construction, relocation or demolition;
11. Additions of less than 250 square feet to any Contributing building
or structure, where the addition does not break the side-planes or
roofl ine of the existing structure, is contained completely within the
rear yard and is not visible from the street;
12. Additions to Non-Contributing structures that increase the square
footage by less than 30% of the existing square footage (as determined
by LADBS) when the addition does not affect the front façade of the
structure or break the side and top planes of the structure;
13. Alterations to façade openings, such as new doors or windows, to
portions of a structure that are not visible from the street;
14. Installation or repair of fences, walls, and hedges in the rear and
side yards that are not visible from the street (non corner-lots only)
and that do not require a Zoning Administrator’s approval for height
or location;
15. Installation or repair of solar collectors, skylights, antennas, satellite
dishes and broadband internet systems on rear-facing facades/roof
surfaces or garage roofs that are not visible from the street;
16. Installation of window security bars or grills, located on secondary
facades;
17. Repair or replacement of gutters and downspouts.
All questions of visibility are to be determined by Department of
City Planning staff. For the purposes of this Plan, visibility includes
all portions of the front and side elevations that are visible from the
adjacent street or sidewalk or that would be visible but are currently
15
Preservation Plan
obscured by landscaping. It also includes undeveloped portions of a lot
where new construction or additions would be visible from the adjacent
street or sidewalk, such as the street-side side yard on a corner lot and
the front yard. Finally, construction or additions to areas that are not
currently visible but that will become visible following the construction
or addition will be considered visible and reviewed accordingly.
A street visible façade excludes those portions of the side elevations
that are not visible from the adjacent street or sidewalk and all rear
elevations. A street visible façade may also include side and rear
facades that are generally visible from a non-adjacent street due to
steep topography, or second stories that are visible over adjacent one
story structures, etc.
Projects requiring a Certifi cate of Appropriateness or Compatibility
shall not have any part of their applications be exempt or delegated.
The Department of City Planning retains the authority to refer any
delegated project to the Historic Preservation Overlay Zone (HPOZ)
Board for a recommendation when compliance with the adopted design
guidelines is unclear.
3.7 Accessory Structures
Any alteration of, addition of less than 250 square feet to, or demolition
of an existing detached accessory structure, on a parcel that has been
designated as a Contributor in the HPOZ, shall be reviewed as a
Conforming Work by the HPOZ Board if it can be demonstrated that
the accessory structure was built outside of the Period of Signifi cance
for the HPOZ. If it cannot be demonstrated that the accessory structure
was built outside of the Period of Signifi cance, the proposed work shall
be addressed through a request for a Certifi cate of Appropriateness
pursuant to 12.20.3 K.4, provided that the Director of Planning, having
weighed recommendations from the HPOZ Board and the Cultural
Heritage Commission, can fi nd the following:
1. That the alteration, addition to, or demolition of the accessory
structure will not degrade the primary structure’s status as a
Contributor in the HPOZ because the accessory structure is not
visible to the general public; or is minimally visible to the general
public; and
2. That the alteration, addition to, or demolition of the accessory
structure will not degrade the primary structure’s status as a
Contributor in the HPOZ because the accessory structure does not
possess physical or architectural qualities that are otherwise found
on the primary structure or that constitute cultural or architectural
signifi cance in their own right; and
16
3. That the accessory structure’s primary historical use has been for
the storage of automobiles (i.e. a garage), or household items (i.e. a
tool shed, garden shed, etc.).
All properties must comply with parking standards set forth in the Los
Angeles Municipal Code.
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Preservation Plan
4.1 History of Western Heights
The historic neighborhood of Western Heights contains 175 parcels, 127
identifi ed as Contributing, and 48 as Non-Contributing resources, with
structures that date back to the late 1800s. Used for agriculture starting
with the Spanish land grant that established the City of Los Angeles,
streetcar extensions facilitated the neighborhood’s development
into a suburban enclave for families who worked downtown. Later
it was home to migrating minorities who were redlined out of other
neighborhoods in Los Angeles. Despite the change that has come to
the commercial storefronts of Washington Blvd which border the area,
the neighborhood has remained mostly unaltered in the last 80 years,
with over 70% of the buildings still retaining the character that makes
them historic.
The Western Heights area is immediately west of the original land
grant given to Spanish settlers in 1781. Lands outside of the land
grant were supplemental to the pueblo lands and were controlled fi rst
by the Spanish and then by the Mexican Governors of Alta California,
and then by the United States after 1847. Until the later part of the
nineteenth century, the area including Western Heights was used
exclusively for grazing and agriculture. Later it was developed as a
series of suburban neighborhoods, except for the independent city of
Watts and small pre-1890 farm communities such as Rosedale (located
near the Rosedale Cemetery). Portions of the area were subdivided for
residential and commercial use beginning in the late 1880’s.
Suburban neighborhoods were developed in response to the extension
of local horse-drawn streetcar routes coming out of downtown Los
Angeles. Signifi cant suburban communities were created in the late
1800s including the eastern section of the West Adams District and
the University District. The horse-drawn streetcar lines were quickly
subsumed by the Los Angeles Transit Lines and Pacifi c Electric Railway
system and upgraded to electric routes, further spurring development
southward in the fi rst decade of the twentieth century. By 1910 only
small sections of the area west of the original pueblo were still used
agriculturally; most of the land had been subdivided into residential
tracts.
Agricultural Development
Agriculture was the primary industry of South Los Angeles from the
fi rst days of the pueblo until residential development consumed the
last large areas of farmland shortly after 1910. The area was fi rst
used for grazing cattle and sheep and later for farming. The farms
grew alfalfa, sugar beets, and vegetables, raised hogs and poultry, and
produced dairy products.
The transfer of one hundred and sixty acres to the Southern District
Agricultural Society in 1872 and the subsequent development of
Agricultural Park on that land was an indication of the signifi cance of
Chapter 4 Context Statement
Pico Boulevard looking east from Western
Avenue in the 1890s. Bicyclists are
riding on the unimproved road.
A man with an ostrich drawn cart receives a
traffi c ticket from a motorycle policeman at 2922
W. Pico Blvd., near Harvard. The cart shows
a sign reading: Los Angeles Ostrich Farm.
18
the agricultural industry to early Los Angeles. Agricultural Park was
initially intended and later re- dedicated to displaying the agricultural
products of the state’s Southern Agricultural District. By 1908,
Exposition Park, as it became known, had become an inner-city park
surrounded by residential neighborhoods.
Wood barns and stables were the predominant built forms associated
with the agricultural industry in South Los Angeles. Utilitarian in
design, they displayed simple gable roof forms and clapboard or
board-and-batten sheathing. Warehouses for packing and shipping
agricultural products were another type of structure associated with
the industry, and were often very large one story buildings. It is
unlikely that any examples of these resource types survive. If identifi ed,
however, even in deteriorated condition, they would be signifi cant
reminders of the region’s agricultural past.
As the dominance of the agricultural industry waned in South Los
Angeles, other industries developed including lumber yards, sash and
door manufacturing companies, a carpet factory, candy company and
a bottled water plant. It is logical that the industries associated with
construction and residential development would be located in the area
as the neighborhoods were being built. Many were located on alleys
or near railroad spurs near Western Heights in order to facilitate
loading activities. Buildings associated with these industries include
warehouses, workshops, and administrative structures.
Streetcar Development & Annexation
The fi rst local streetcars reached the area around Rosedale Cemetery
and the University District in the early 1890’s, prompting the migration
of wealthy businessmen from downtown Los Angeles. The fi rst east-
west streets to become major thoroughfares included Pico, Washington
and Jefferson Boulevards. .
While the railroads and Pacifi c Electric system spurred the growth
of outlying communities, local streetcars, begun as independent
franchises using horse-drawn cars, also spurred development within
the residential subdivisions close to downtown Los Angeles. All of the
local streetcars were later electrifi ed and eventually absorbed into the
Los Angeles Transit Lines (the “Yellow Cars”). Usually there was a
direct relationship between the streetcar routes and the development
of residential tracts. Another signifi cant streetcar routes included the
Washington Street line to Rosedale Cemetery (1895). Development of
each line was motivated by the desire to sell real estate in the area.
The resources associated with rail transportation include depots,
platforms, substations, and track right-of-ways.
As residential communities developed, citizens increasingly perceived
a need for services beyond those provided by the initial subdividers and
real estate entrepreneurs. Primary among these services were water
distribution and law enforcement, which often implied a regulation
General view of Exposition Park looking north toward
Mudd Hall at the University of Southern California
Passengers aboard the Pacifi c Electric
Venice Line circa 1920.
19
Preservation Plan
and curtailment of liquor consumption. As a result of these needs,
areas west of the Pueblo were annexed to the City of Los Angeles.
The Southern and Western Addition of 1896 was the third annexation
from when the city was fi rst founded, and included over ten square
miles in two roughly rectangular sections adjacent to the original city
boundaries; Western Heights was included in this annexation.
The availability and distribution of water for agricultural and residential
use was of primary importance in every area of Los Angeles. Concern
about water was one of the most common motivations for annexation
to the City of Los Angeles and, as a result, water was an important
catalyst in the political development of the region as well as in the
determination of agricultural and residential land use. In other parts
of South Los Angeles, artesian wells were the primary source of water.
Although none of these structures exist in Western Heights, nearby the
resources associated with water distribution include artesian wells as
well as the larger distributing stations erected by the Department of
Water and Power in residential areas during the 1930’s
Residential Development
The residential development of South Los Angeles from its fi rst
settlement until 1950 was a powerful and persistent factor in the
organization of the community’s built environment. The routes of
streetcars and electric railways in most cases determined the fi rst
areas of concentrated residential development and hastened the
“suburbanization” of outlying farm communities. Many residential
neighborhoods were developed in very short periods of time by single
developers. As a result they demonstrate a consistency of architectural
style, size, and scale. In other areas, residential development occurred
over two or three decades and continued to change as older structures
were replaced by newer ones. These neighborhoods evolved a variety
of characteristics that today document changes in population, income
level, and in the architectural conventions preferred by successive
generations.
The original subdivisions that composed the survey area were:
• Orange Crest Tract between Washington Boulevard on the north
and 20th Street on the south, and the line of the Cribb & Sinclair’s
West Garfi eld Heights Tract on the east and Arlington Avenue on
the west;
• Cribb & Sinclair’s Garfi eld Heights Tract between Washington on
the north and 21st Street on the south, and Gramercy Place on the
east and Cimarron on the west;
• Cribb & Sinclair’s West Garfi eld Heights Tract between Washington
Boulevard on the north and 21st Street on the south, and Cimarron
on the east and on the west the boundary lines of the Orange Crest
Washington Boulevard, near Arlington
Avenue, festively decorated with fl ags in the
mid-1920s. A sign on a brick building says
“United.” Cars are seen on the street.
Washington Boulevard near Western Avenue
20
Tract north of 20th Street and the Robert Marsh & Co.’s Florence
Heights Track south of 20th Street;
• Robert Marsh & Co.’s Florence Heights Tract between 20th Street
on the north and 21st on the south, and the boundary line of the
Cribb & Sinclair’s West Garfi eld Heights Tract on the west and
Arlington on the west;
• Kinney Heights Tract between 21st Street on the north and 23rd
Street on the south (the lower portion of this tract is now south of
the I-10 Freeway, and Gramercy Place on the east and Arlington
on the west;
• Belvedere Heights Tract between Washington on the north and
21st Street on the south, and the boundary line of the Robert Marsh
& Co.’s Western Heights Tract on the east and Gramercy Place on
the west;
• Robert Marsh & Co.’s Western Heights Tract between Washington
on the north and 21st Street on the south, and Western on the east
and the boundary line of the Belevdere Heights Tract on the west.
Patterns of residential development contributed not only to the
physical characteristics of the built environment, but also to the social
environment of South Los Angeles; it became associated with various
ethnic and immigrant populations. Restrictive covenants instituted in
other sections of Los Angeles led to settlements of several neighborhoods
in this area by Blacks. By 1920, most of Los Angeles’s Black population
lived in a few district scattered throughout South Los Angeles. At the
same time there were additional pockets of residential neighborhoods
associated with other ethnic groups throughout the area.
Single Family Homes
Home ownership was a cultural value embraced by almost every
generation and ethnic group of settlers that came to California when
residential subdivision began in the 1880’s. Many local real estate
entrepreneurs capitalized on the universal desire to own property. Prior
to that time, few dwellings were built in South Los Angeles. Structures
from the early Spanish and Mexican periods were constructed of adobe.
Associated with agricultural land uses, the adobe ranch house was later
joined by the fi rst wood frame farm houses constructed by American
immigrants from the East and Midwest. The farmers from Maine
built two story frame houses much like the ones they remembered in
New England. As residential subdivision gained momentum, the adobe
homestead and the Maine farmhouse were joined by a proliferation of
one story Craftsman and period revival style bungalows.
Subdivisions in the north part of the South Los Angeles were directed
at wealthy middle class families rather than the working class that
populated other sections of the area. As a result, the homes were large
Stone marker placed by West Adams Heights
tract realtors at Washington Boulevard. The top
portion of the marker has an intricate street
lamp with its base made up of steel scrolls.
Intersection at Washington Boulevard,
west from Western Avenue. Numerous
shops line both sides of the street.
21
Preservation Plan
and lavish. The fi rst wave of concentrated residential development in
eastern West Adams and the University District consisted largely of
Los Angeles businessmen and their families who wished to move out of
the central city but needed to remain within easy commuting distance
of downtown. The streetcar systems that traversed Pico, Washington,
and Jefferson initially made this kind of suburban settlement possible.
Men of means who had achieved a certain wealth and stature in Los
Angeles constructed large residences in the area from 1890 into the
1920’s.
As a result of the overwhelming desire for home ownership and the
subdivision patterns, the single family home was the predominant
resource type of residential development in Western Heights. House
type, size, site characteristics, and architectural style varied greatly
from community to community, but the subdivision of tracts into lots
for single family homes proceeded at a relentless pace throughout the
region in the early decades of the 20th century.
Single family homes in Western Heights include a broad range of styles
and scale. Craftsman bungalows included the stone foundations, porch
supports, and chimneys that typifi ed the style. Wood sheathing or
shingles, protruding rafters, the low, horizontal emphasis, and other
hallmarks combined to create a regional aesthetic loosely derived from
the Arts and Crafts Movement in England and America. Colonial
Revival examples typically included a symmetrical facade with columns
fl anking the doorway. Clapboard sheathing and clipped gable roof
forms were also typical. The Spanish Revival and Mission styles had
stucco walls, red tile roofs or overhangs, and frequently incorporated
arched windows and details as well as other elements derived from the
California missions. Tudor style homes included steeply pitched roofs
and stucco and half-timber wall designs.
The works of many distinguished local architects are found in South Los
Angeles including Sumner Hunt, Theodore A. Eisen, Carroll H. Brown,
John Parkinson, Hudson and Munsell, Frank M. Tyler, and many.
Designed for specifi c clients or speculative builders, the works of these
architects graced subdivisions owned and promoted by entrepreneurs
such as Frederick Rindge and George Ira Cochran of West Adams
Heights, Abbot Kinney, who later founded the resort community of
Venice, and. A concentration of these structures in neighborhoods and
districts collectively tell the story of residential development in Los
Angeles.
Multi Family Residential Structures
Residential development in Western Heights was not limited to
single family homes, but included multi-family resource types such
as duplexes, “railroad courts” and bungalow courts, and apartment
buildings. Executed in the same styles and materials as single
family homes, these structures in most cases served the working class
Mission Revival residence at Arlington Ave & 21st
Street, displaced by Santa Monica Freeway.
22
population of each community for whom home ownership was not
economically feasible or whose work was of a more transient nature.
Builders developed strategies both to effi ciently house workers and
to bolster the attractiveness of apartment living, often incorporating
features of single family residences into multi-family dwellings.
“Railroad courts” or “tenements,” which were developed in Watts and
initially housed Black and Mexican-American laborers, were whole
complexes of independent or adjoining one room structures of wood
clapboard with gable roofs. Small and inexpensive to build, these
linear courts often lacked the central exterior courtyard of bungalow
courts but both arrangements provided the security of an individual
structure within a community of similar residences. The number of
minorities immigrating to Los Angeles increased in the 1920s and the
number of neighborhoods open to Blacks decreased as a result of new
subdivisions, which included restricted covenants on ownership and
occupancy. These opposing trends of growth and containment caused
the population of South Central Avenue and Watts neighborhoods to
increase dramatically. When this occurred, single family homes gave
way to larger structures including these fi rst “tenements” and apartment
buildings. Other apartment arrangements included courtyard or
garden apartments each with access to an outdoor open space which,
together with bungalow courts, defi ned a regional relationship between
housing and the landscape.
Later multi-family residential structures included masonry apartment
buildings. These apartment buildings were larger than their
“tenement” precursors, and often ornamented in a variety of styles.
A direct result of Los Angeles’s exponential population growth in the
1920’s, many of these apartment buildings still stand and are essential
to understanding Los Angeles’ housing patterns.
Resources Associated with Minority Heritage
Many different ethnic groups made substantial contributions to the
historic and cultural heritage of South Los Angeles. Some examples of
resource types associated with these residents of these neighborhoods
have been mentioned in preceding paragraphs.
Housing stock used by Blacks and by other minority groups such as
the Mexican-Americans who labored on the railroad lines, may survive
and can be traced through early maps and directories. Examples that
survive may not only be of signifi cance to each individual ethnic group,
but may demonstrate a sequential residential pattern signifi cant to all
those who shared the neighborhoods and communities of South Los
Angeles.
23
Preservation Plan
4.2 Western Heights Period of Signifi cance
19
TH
CENTURY STYLES (1860s – 1900s)
American Foursquare
Classical Revival (Also, Neo-classical Revival,
Beaux Arts, Greek Revival)
Folk Victorian
Queen Anne
Shingle
ARTS & CRAFTS TURN OF THE CENTURY STYLES (1890s – 1920s)
Colonial Revival
Craftsman (Also, Transitional Arts & Crafts, Tudor
Craftsman, Japanese Craftsman, etc.)
Mission Revival
Prairie
ECLECTIC REVIVAL STYLES (1915 – 1940)
Dutch Colonial Revival
English Tudor Revival (Also, English Revival, English Cottage, etc.)
French Eclectic Revival (Also French Normandie, French Revival, etc.)
Italian Renaissance Revival
Mediterranean Revival
Spanish Colonial Revival
EARLY MODERN STYLES (1900 – 1950s)
Minimal Traditional
Moderne (Also Streamline Moderne)
24
25
Preservation Plan
Chapter 5 The Historic Resources Survey
5.1 Introduction
The historic resources survey is a document which identifi es all
Contributing and Non-contributing structures and all Contributing
landscaping, natural features and sites, individually or collectively,
including street features, furniture or fi xtures, and which is certifi ed as
to its accuracy and completeness by the cultural heritage commission.
5.2 Contributing or Non-contributing?
To fi nd out if a particular structure, landscape feature, natural
features, or site is Contributing, consult the Historic Resource Survey.
Depending on the Contributing/Non-contributing status of a structure,
feature, or site, different elements of the design guidelines will be used
in the planning and review of projects.
Contributing Structures
Contributing structures are those structures, landscape features,
natural features, or sites identifi ed as Contributing in the Historic
Resources survey for the HPOZ. Generally, “Contributing” structures
will have been built within the historic Period of Signifi cance of the
HPOZ, and will retain elements that identify it as belonging to that
period. The historic period of signifi cance of the HPOZ is usually the
time period in which the majority of construction in the area occurred. In
some instances, structures that are compatible with the architecture of
that period or that are historic in their own right, but were built outside
of the Period of Signifi cance of the district, will also be “Contributing”.
Contributing Altered
Contributing Altered structures are structures that date from the
period of signifi cance, built in the same time period as Contributing
structures that have retained their historic character in spite of
subsequent alterations or additions and are deemed reversible.
Non-contributing Structures
Non-contributing structures are those structures, landscapes, natural
features, or sites identifi ed as not retaining their historic character as
a result of un-reversable alterations, or as having been built outside of
the HPOZ Period of Signifi cance or because they are vacant lots.
The Western Heights Historic Resources Survey can be reviewed at:
City Hall
City Planning Department, Offi ce of Historic Resources
200 N Spring Street, Room 620
Los Angeles, CA 90021
26
27
Preservation Plan
A Japanese-American family sits for a photograph
in front of their Queen Anne cottage in Garvanza.
The E.C. Hurd residence, which stood
at 6954 Hollywood Blvd is shown with
ornate Queen Anne detailing.
Chapter 6 Architectural Styles
6.1 Overview of Architectural
Styles in Los Angeles
The following is a history of architectural styles found throughout the
City of Los Angeles. The narrative of architectural styles is helpful in
understanding how the architecture of the HPOZ relates to the larger
region-wide context. The summary of styles and periods is intentionally
broad and is intended to give the reader an understanding of major
architectural themes in the City. However, it should be understood
that individual structures may adhere rigorously to the themes and
descriptions described below, or may defy them altogether based upon
the preferences and tastes of individual architects, home-builders and
developers.
Nineteenth Century Styles (1880s–1900s)
The 19th Century architectural styles popular in Los Angeles included
the Italianate, Queen Anne, Folk Victorian, and Eastlake/Stick styles;
styles that many lay-people might refer to simply as “Victorian.” Most of
these styles were transmitted to Los Angeles by means of pattern books
or the experience of builders from the eastern United States. Later
in the period builders began to embrace more simplifi ed home plans
and the Foursquare, Shingle and Victorian Vernacular styles began
to emerge (Victorian Vernacular styles generally include the Hipped-
roof Cottage and the Gabled-roof Cottage). Neo-classical styles were
also popular during this period. While there are residential examples
of Neo-classical architecture, the styles is most often attributed to
commercial and institutional structures.
These 19th Century styles were built most prolifi cally in the boom
years of the 1880s, with consistent building continuing through the
turn of the last century. These styles were concentrated in areas
near today’s downtown Los Angeles. Many examples of 19th century
architectural styles have been lost through redevelopment or urban
renewal projects. Surviving examples of 19th Century architectural
styles within the City of Los Angeles are most commonly found in
neighborhoods surrounding the Downtown area such as Angelino
Heights, University Park, Boyle Heights, Lincoln Heights, and South
Los Angeles. Surviving examples of the pure Italianate styles are rare
in Los Angeles, although Italianate detail is often found mixed with the
Eastlake or Queen Anne styles.
The prominent architects in Los Angeles in this period included Ezra
Kysar, Morgan & Walls, Bradbeer & Ferris, Frederick Roehrig and
Carroll Brown.
28
This Mission Revival home once stood
where the present-day Hollywood/Highland
development is currently located.
Spanish Colonial Revival emerged as a popular style
for many neighborhoods in the Mid-Wilshire area.
A collection of early Craftsman and Foursquare
homes is shown in the Harvard Heights
neighborhood (Western Ave. north of Venice Blvd.)
Arts & Crafts/Turn of the Century Styles (1890s–1910s)
The late 1800s and early 1900s saw a substantial change in design
philosophy nation-wide. The Arts and Crafts Movement, born in
Western Europe rejected the rigidity and formality of Victorian era
design motifs and embraced styles that were more organic and that
emphasized craftsmanship and function. During this time in Los
Angeles, architectural styles that emerged in popularity include the
Craftsman Style in its various iterations (Japanese, Swiss, Tudor, etc.);
the Mission Revival Style, unique to the southwestern portion of the
United States; and the Prairie Style, initially popularized in the Mid-
west and Prairie states. Colonial Revival styles, including American
Colonial Revival (inspired by architecture of the early American
Colonies) and Spanish Colonial Revival (inspired by architecture of the
early Spanish colonies) also emerged in popularity during this period,
though there is a stronger preponderance of these styles later during
the Eclectic Revival period of early to mid-century.
These styles were concentrated in areas spreading from downtown
Los Angeles into some of the area’s fi rst streetcar suburbs. Although
many examples of these styles have been lost through redevelopment,
fi re, and deterioration, many fi ne examples of these styles still exist in
Los Angeles. These styles can be commonly found in the greater West
Adams area, portions of South Los Angeles, Hollywood and throughout
the Northeast Los Angeles environments.
In this period, Los Angeles was beginning to develop a broad base of
prominent architects. Prominent architects in Los Angeles during this
period included Henry and Charles Greene, the Heineman Brothers,
Frank Tyler, Sumner Hunt, Frederick Roehrig, Milwaukee Building
Co., Morgan & Walls, J. Martyn Haenke, Hunt & Burns, Charles
Plummer, Theodore Eisen, Elmer Grey, Hudson & Munsell, Dennis
& Farwell, Charles Whittlesby, and Thornton Fitzhugh. Only one
surviving example of the work of architects Charles and Henry Greene
survives in Los Angeles, in the Harvard Heights HPOZ.
The Eclectic Revival Styles (1915–1940s)
The period between the World Wars was one of intense building
activity in Los Angeles, and a wide range of revival styles emerged in
popularity. The Eclectic Revival styles, which draw upon romanticized
notions of European, Mediterranean and other ethnic architectural
styles, include Colonial Revival; Dutch Colonial Revival; English
and English Tudor Revival styles; French Eclectic styles; Italian
Renaissance Revival; Mediterranean Revival; Monterey Revival;
Spanish Colonial Revival; and to a lesser extent, highly stylized ethnic
revival styles such as Egyptian Revival, and Hispano-Moorish styles.
Use of the Craftsman Style continued through this period as well.
Many of these styles were widely adapted to residential, commercial
and institutional use. Styles such as Egyptian Revival, Chateauesque
29
Preservation Plan
The Eclectic Revival (or Period Revival)
movement presents a number of romantic
building styles to this single streetscape.
Los Angeles’ love of the auto is often refl ected
in Art Deco and Streamline styles.
Richard J. Neutra’s Strathmore Apartments in
Westwood, built in 1937, are an example of
the cutting-edge early International Style.
(a French Eclectic style) Mediterranean Revival and Spanish Colonial
Revival being particularly popular for use in small and large scale
apartment buildings.
All of these styles were based on an exuberantly free adaptation of
previous historic or “foreign” architectural styles. The Los Angeles
area is home to the largest and most fully developed collection of these
styles in the country, probably due to the combination of the building
boom that occurred in this region in the 1920s and the infl uence of the
creative spirit of the fi lm industry.
Prominent architects working in these styles included Paul Revere
Williams, Walker & Eisen, Curlett & Beelman, Reginald Johnson,
Gordon Kauffman, Roland Coates, Arthur R. Kelley, Carleton M.
Winslow, and Wallace Neff. Many surviving examples of these styles
exist in Los Angeles, particularly in the Mid-Wilshire, Mid City and
Hollywood environments.
The Early Modern Styles (1900s–1950s)
The period between the World Wars was also a fertile one for the
development of architectural styles that were based on an aggressively
modern aesthetic, with clean lines and new styles of geometric
decoration, or none at all. The Modern styles: Art Deco, Art Moderne,
and Streamline Moderne and the International Style, all took root and
fl ourished in the Los Angeles area during this period. The infl uence
of the clean lines of these styles also gave birth to another style, the
Minimal Traditional style, that combined the sparseness and clean
lines of the Moderne styles with a thin veneer of the historic revival
styles. Early Modern styles were most readily adapted to commercial,
institutional and in some cases, multi-family residential structures
citywide, though there is certainly a preponderance of early modern
single family residential structures in the Silver Lake and Echo Park
areas, Hollywood, the Santa Monica Mountains, Mid-Wilshire and
West Los Angeles areas.
Prominent architects in the Los Angeles region working in these styles
included Richard Neutra, Paul Revere Williams, R.M. Schindler, Stiles
O. Clements, Robert Derrah, Milton Black, Lloyd Wright, and Irving
Gill.
Post-World War II/Response to Early Modern (1945–1965)
The period dating from 1945-1965 saw an enormous explosion in the
development of single-family housing in the Los Angeles area. Much of
this development took the architectural vocabulary of the pre-war years
and combined it into simplifi ed styles suitable for mass developments
and small-scale apartments. Residential architectural styles popular in
Los Angeles in this period included the Minimal Traditional, the various
Ranch styles, Mid-Century Modern styles such as Post and Beam and
30
The Dingbat, a product of 1950s Los
Angeles, combines a basic utilitarian
form with fanciful design motifs.
The Post-War building boom brought inexpensive
and plentiful housing to the San Fernando Valley.
Contemporary, and the Stucco Box (most popularly expressed in the
Dingbat type). Though these styles may be found as in-fi ll development
throughout the City, areas where complete districts of these styles may
be found in Los Angeles include Westchester, West Los Angeles, the
Santa Monica Mountains and the San Fernando Valley.
Prominent architects working in these styles in Los Angeles included
Gregory Ain, A. Quincy Jones, J. R. Davidson, Cliff May, John Lautner,
William Pereira, Rapahael Soriano, and H. Hamilton Harris, although
many of these styles were builder-developed.
31
Preservation Plan
6.2 Building Types
The diversity of building periods and architectural styles in Los Angeles
is matched only by the diversity of building types. The cityscape is
marked by single family homes, big and small; multi-family structures
of varying sizes and densities and a breadth of commercial and
institutional buildings varying in scale and function. An understanding
of building types can be especially helpful in planning and evaluating
an in-fi ll project in a historical context. Some architectural styles in
Los Angeles, such as the Spanish Colonial Revival style have been
gracefully adapted to a wide range of residential, commercial and
institutional building types. Other styles tend to only have been applied
to particular building types; for example, the Art Deco style tends to
be found most often on commercial and institutional building types,
and the Craftsman style, a predominant residential style was rarely
applied to commercial building types. While it is important to address
issues of architectural style, it is equally important to ensure that new
projects fi t in their context with respect to function, layout and type.
Single Family Homes
Though most single family homes may be similar by virtue of their use,
there is a signifi cant range of single family building types within Los
Angeles. Some neighborhoods may be characterized by standard two-
to-three story single family homes, and others may be characterized
by cottages or bungalows—simple one-story to one-and-a-half-story
homes. Idiosyncratic building types may also exist in particular
neighborhoods. For example, the Villa, a two-story home oriented
lengthwise along the street may be popularly found in affl uent pre-war
suburbs throughout the Mid-City and Mid-Wilshire areas. While there
are always exceptions, attention should be paid to which architectural
styles are applied to which single family home types. For example, the
English Tudor Revival style has usually been applied to large single
family homes, while the simpler English Revival style has usually been
applied to bungalows and cottages. The various design guidelines in
this document are intended to ensure that additions to single family
homes, as well as in-fi ll projects do not defy established building types
as well as architectural styles.
Multi-Family Homes
A wide range of multi-family building types were adapted in historic
Los Angeles. Some, such as simple duplexes or garden style apartments
were designed to blend with the surrounding single family context,
and others, such as traditional four-plexes, one-over-one duplexes or
large scale apartment buildings defi ne neighborhoods in their own
right. When planning a multi-family project, special attention should
be paid to predominant building types, and to what styles are most
often applied to those types, to ensure that the project is compatible
32
with the surrounding neighborhood. For example, there tend not to be
Craftsman style large-scale apartment buildings, though the style is
readily applied to duplexes and fourplexes. The Multi-Family In-Fill
design guidelines in Chapter 9 provide a clear understanding of the
specifi c multi-family building types.
Commercial and Institutional Uses
While the majority of parcels within Los Angeles HPOZs tend to be
residential, there is a signifi cant number of commercial buildings and
commercial uses within HPOZ purview. Most commercial buildings
in HPOZs tend to be simple one-story and two-story buildings built
along the street frontage with traditional store-fronts and offi ces or
apartments above. Institutional building types tend to be defi ned by
their use: churches, schools, libraries, etc. Successful in-fi ll projects
will adhere both to prevailing architectural styles and building types.
The Commercial Rehabilitation and In-Fill chapters (Chapters 10 and
11) provide assistance in this area.
33
Preservation Plan
6.3 Introduction to
Western Heights Architectural Styles
The Architectural Styles Chapter of this Plan is intended to give an
overview of the predominant styles that may exist in the Western
Heights HPOZ. Each architectural style explanation has been divided
into two sections, a textual overview of the style and its development,
and a listing of some typical signifi cant architectural features of that
style. These descriptions are intended to assist property owners and
the HPOZ board in determining the predominant architectural style
of a structure, and in understanding the elements of that style. These
descriptions are not intended as comprehensive lists of signifi cant
features of any style, and are not to be taken as an exhaustive list
of what features should be preserved. Rather, they are intended as a
starting point for discussion about what rehabilitation or restoration
projects might be appropriate to a particular property.
The reader may note that each architectural style description contains
a note on what architectural styles can commonly be found mixed
together. This note is included because architectural styles are not
always found in a pure state. Individual owners and builders quite
often customized or mixed the elements of different architectural styles
together in designing a structure. This may be because cultural tastes
were transitioning between two styles, with some styles falling out of
favor and new styles being introduced, or simply due to the personal
taste of the designer. It is important to realize that these mixed style
structures are no less architecturally signifi cant than the “purer”
forms of a particular style, and that mixed style structures are not
“improved” through remodeling with the goal of achieving a “pure”
style. Los Angeles is particularly rich in inventive, “fantasy” structures
that show a great deal of creativity on the part of the architect, owner,
and builder, and this richness should be preserved.
The architectural style descriptions may contain some unfamiliar
terms. Many of these terms are defi ned in the Defi nitions chapter
located at the end of this Preservation Plan, or are illustrated within
the Design Guidelines chapters.
34
35
Preservation Plan
19th Century Styles: American Foursquare
Background
The American Foursquare style is a residential style frequently used in
Los Angeles from the turn of the last century through the 1910s. Popular
in American suburban development, the style lent itself to low-cost
design that maximized square footage on small lots while presenting a
dignifi ed appearance. A precursor to the Craftsman and Prairie styles,
Foursquare houses tended to avoid the ornate detail associated with
styles such as Queen Anne and Eastlake.
Common Components of the Foursquare Style
A Foursquare house is generally two stories, with a simple square or
rectangular footprint, a low-pitched, usually hipped, roof, a front hipped-
dormer, and a substantial, though often asymmetrical front porch.
Columns suggestive of the classical orders, dentils, and traditional
moldings are also commonly found on Foursquare houses, though the
popularity of the Craftsman style in the West Adams area brings Arts
and Crafts details to many Foursquare houses and the Foursquare
house in many ways has served as a canvas by which other architectural
styles have emerged. Windows are always rectangular and may be
arranged singularly or in groups—often the fi rst fl oor will have grouped
windows and the upper-fl oor will have singular windows. Doorways are
also rectangular and tend to be wide, often with large panes of glass in
the door or as side lights. Cladding may be masonry, clapboard or to a
lesser extent stucco.
General Characteristics:
• Simple fl oor plan
• Boxy, cubic shape
• Full width or off-set front porch with columnar supports and wide
stairs
• Offset front entry in an otherwise symmetrical facade
• Two to two-and-a-half stories
• Pyramidal, hipped roof, often with wide eaves
• Large central dormer
• Large single light windows in front, otherwise double hung
• Incorporated design elements from other contemporaneous styles,
but usually in simple applications
• Simple and restrained two-color and three-color paint schemes
highlighting body, trim and accents
36
19th Century Styles: Classical Revival
(Includes Neo-Classical Revival, Beaux Arts, Greek Revival)
Background
The various Classical Revival styles, including Neo-classical Revival,
were popularly used in Los Angeles from the mid 1800s through the
1930s, though the style remained en vogue with institutional and
commercial structures through the Second World War. Many attribute
the popularity of the Classical Revival styles to the City Beautiful
Movement, born out of the World Columbian Exposition held in Chicago
in 1893, though the style was in use prior to that event.
Common Components of the Neo-classical Revival Styles
The Neoclassical Revival style is closely related to both the Greek
Revival and Colonial Revival styles. The style’s earlier iterations
are generally adapted to large houses. A double height front portico
with Ionic or Corinthian columns tends to be a hallmark of the style.
Windows are generally arranged singularly and may be adorned with
lentils. Roofs are often hipped or with side-facing gables. Neo-classical
design features such as columns, pediments may be found on smaller
homes and are often mixed with Greek Revival, Colonial Revival and
Italian Renaissance Revival homes as each of these styles draws from
antient classical building forms.
General Characteristics
• Massive symmetrical and rectilinear form
• Low pitched roof
• Decorative dentils along eaves
• Triangular pediments supported by classic columns
• Large rectangular windows, usually arranged singularly
• Decorative plaster elements
• Masonry walls
• Color schemes indicative of stone and masonry construction
37
Preservation Plan
19th Century Styles: Queen Anne
Background
The Queen Anne, popularized in England in the mid 1800s and later
in the US, was modeled loosely on Medieval Elizabethan and Jacobean
architecture and in many ways is a statement of the excesses of the
Victorian era. Many of the largest and most impressive homes of this
period where built in the Queen Anne style. Innovations in balloon
frame construction allowed builders of Queen Anne homes to create
complex fl oor plans, which resulted in equally complex elevations
and the style was thus a reaction to the classical symmetry of earlier
styles. Industrial innovations such as mass production facilitated the
use of complex house components like doors, windows, roofi ng, and
decorative details. In the United States, craftsman added their own
touches with intricate spindles and other stylized wooden details.
Common Characteristics of the Queen Anne Style
The Queen Anne Revival style is exemplifi ed by an asymmetrical fl oor
plan, gabled roofs with exposed decorative trusses, towers, patterned
wooden wall cladding, wrap-around porches, bay windows and
patterned masonry. Queen Anne Revival buildings are typically one to
two stories, with wide eaves and decorative brackets, and rectangular
windows. Fish scale shingle siding and decorative clapboard is often
employed in various patterns and cuts, as well as spindle work, bay
windows and bump outs. Towers are often used with imaginatively
shaped roofs ranging from cones and bell shapes to octagons and domes
with decorative fi nials. Interestingly, towers placed at the corner of
the front facade are most often a characteristic of the Queen Anne
style, whereas placement is often elsewhere on other styles like the
Victorian Stick style. Wrap around porches are very common.
General Characteristics
• Complex and steeply pitched roof forms with cross gables and
front-facing gables. Towers and turrets are common.
• Long, narrow double hung windows, ornate stained glass
• Highly ornamented with spindle work, fi nials, roof cresting, corner
brackets on porches and cutouts.
• Fanciful shingle and clapboard
• Parapets and brickwork are often variably colored and patterned
and highly decorative.
• Covered porches often wrap from the front and around a side and
are decorated with spindle work and friezes.
• Chimneys may be patterned masonry and are sometimes seen
with chimney pots.
• Complex and contrasting color schemes highlight ornate wood-work
38
19th Century Styles: Shingle
Background
The Shingle style was popular in Los Angeles during the 1880s through
the 1900s and appealed to homebuilders who desired homes less
decorative and opulent than the Queen Anne and Eastlake styles. The
Shingle style is often thought of as an eclectic American adaptation
of the Queen Anne, Colonial Revival and Richardsonian Romanesque
styles and the style has been successfully adapted to homes large and
small. By covering most or all of a building with shingles stained a
single color, architects created a uniform, unembellished surface and a
clean, pure aesthetic.
Common Components of the Shingle Style
The Shingle style features walls and roofs clad in shingles, with
asymmetrical facades. Structures are typically two stories, with steeply
pitched roofs, gables, narrow eaves, and large wrapping porches. The
extensive use of shingles de-emphasizes other elements of the façade,
such as cornices and windows. The Shingle style features are found
mixed in with Queen Anne, Classical Revival, Stick, and Arts and
Crafts styles. Given the popularity of the Craftsman style in the West
Adams area, most Shingle style homes incorporate Craftsman design
themes such as exposed rafters and complex cross-gables.
General Characteristics
• Asymmetrical facades and roof forms
• Complex cross-gables and front-facing gables
• Occasional use of gambrel roof
• Clad with naturally stained shingle
• Simple eaves
• Rough-hewn stone foundations and porch supports
• Rectangular, grouped, double-hung windows
• Stained shingles in natural tones with one or two trim/accent colors
39
Preservation Plan
Arts & Crafts/Turn of the Century Styles: Colonial Revival
Background
Early use of the Colonial Revival style dates from 1890 and it remained
popular through the 1950s (consequently, it may also be considered
part of 19th Century Styles Period or the Eclectic Revival Period).
Popularity of the style resulted from a rejection of the ornate European
inspired styles such as Queen Anne, and a desire to return to a more
“traditional” American building type. This popularity was reinforced
by the City Beautiful movement which gave attention to Neo-classical
building forms. Colonial Revival took on added popularity with the
restoration of Colonial Williamsburg in the 1920s. This style draws from
the simple building forms typical of early American colonial structures,
and elements of classical or Georgian architecture. It is closely related
to the Neoclassical Revival and Georgian Revival styles.
Common Characteristics of the Colonial Revival Style
Colonial Revival residential structures are typically one or two stories,
with hipped or gabled roofs (gables nearly always oriented to the sides of
the structure) and symmetrical facades. Porches tend to be diminutive if
present at all, and entryways are often adorned with decorative crowns
or pediments and square or round columns. Doorways are generally
single and are rectangular. Windows on older Arts and Crafts period
structures, may be arranged in pairs or threes, though later Eclectic
Revival Colonial houses often have windows arranged singularly with
shutters. More decorative versions of Colonial Revival, such as Adam
Revival, Federal Revival or Georgian Revival may integrate Neo-
classical design motifs such as quoins and dental brackets. The entryway
or porch is the primary focus, often highlighted with a decorative crown
or pediment. Commercial structures are usually low in scale.Elements
of the Colonial Revival style are often found mixed with the Queen Anne
and Craftsman architectural styles.
General Characteristics
• Symmetrical Facades, and occasional use of side-porch
• Basic rectangular shape
• Hipped or side-facing gable roof
• Multi-pane double-hung windows, often adorned with shutters
• Central entrance usually adorned with pediments and decorative
crown
• Diminutive or no front porch
• High-style variants may use dormers, quoins, dentils and full-
height classical columns
• Two or three-color paint schemes with house body often in
light or white tones
40
Arts & Crafts/Turn of theCentury Styles: Craftsman
(Also Japanese Craftsman, Swiss Craftsman, Tudor Craftsman)
Background
Quintessential to the Arts and Crafts design movement, Craftsman
architecture stressed the importance of craftsmanship, simplicity,
adapting form to function, and relating the building to the surrounding
landscape through its ground-hugging massing and orientation. Many
early Craftsman homes utilized design elements also found on English
Tudor Revival homes such as exposed half-timbers, a steeply pitched
roof and plaster façade surfaces. (These structures may be identify
as “Transitional Arts and Crafts.”) Later, the Craftsman style was
simplifi ed and often reduced to signature design elements such as
an offset front gable roof, tapered porch piers, and extended lintels
over door and window openings. In many cases, the Craftsman style
incorporated distinctive elements from other architectural styles
resulting in numerous variations (namely Asian and Swiss infl uences).
The Craftsman style is found in single family homes, duplexes, four-
plexes and apartment houses are not uncommon. Though larger
Craftsman homes are common in West Adams, the style is perhaps best
known in the Bungalow type: single-story smaller homes built from kits
or pre-drawn catalogue plans. The Airplane Bungalow is a building type
that is wholly unique to the Craftsman style and generally consists of a
Bungalow with a small pop-up second story (resembling, to some extent,
an airplane cockpit
Common Characteristics of the Craftsman Style
Craftsman architecture is usually characterized by a rustic aesthetic
of shallowly pitched overhanging gable roofs; earth-colored wood siding;
spacious, often L-shaped porches; windows, both casement and double-
hung sash, grouped in threes and fours; natural wood for the front doors
and through-out the interior; and exposed structural elements such as
beams, rafters, braces and joints. Cobblestone or brick was favored for
chimneys, porch supports and foundations. Craftsman structures may
also exhibit characteristics of Prairie and Mission Revival styles.
General Characteristics
• Broad gabled roofs with deeply overhanging eaves
• Pronounced front porch, symmetrical or offset with massive
battered or elephantine columns
• Exposed and decorative beams, rafters, vents
• Decorative brackets and braces
• Grouped rectangular multi-pane windows
• Massive stone or masonry chimneys
• Use of earth tone color palette and natural fi nishes
• Three-color schemes for body, trim and accents
41
Preservation Plan
Arts & Crafts/Turn of the Century Styles: Mission Revival
Background
The Mission Revival style was born in California in the 1890s. It has
been an enduring architectural style, and examples continue to be
constructed into the present day, although in much smaller numbers
than in its heyday in the 1910s and 1920s and with less of an emphasis
on Arts and Crafts detail. The Mission Revival style owes its popularity
in large part to the publication of “Ramona” in the late 19th Century,
the release of the Mary Pickford fi lm of the same title in 1910, and
the consequent romanticization of the Mission era in California and
resurgence of interest in the Spanish heritage of the southwestern
United States.
Common Characteristics of the Mission Revival Style
Mission Revival structures are generally clad with stucco and employ
sculpted parapets (espandanas), and arched openings refl ected the
simplicity of Southern California’s Mexican and Spanish heritage.
Mission Revival style residential structures are typically two or three
stories (commercial structures typically are no more than four), have
low pitched roofs with gables and wide eaves, arched arcades enclosing
large, front porches, a mixture of small square windows, and long,
rectangular windows, quatrefoils, Moorish detailing and often towers.
The features of the Mission Revival style are often mixed with the
Spanish Colonial Revival, Craftsman, Prairie and Hispano-Moorish
styles. While the Mission Revival style may easily be confused with
other Mediterranean and Spanish styles a true Mission Revival
structure will exhibit the intricacy of detail associated with the Arts
and Crafts movement and will embody the rustic nature of the early
California Missions over the ornate formality of other Spanish Colonial
settlements.
General Characteristics
• Simple, smooth stucco or plaster siding
• Broad, overhanging eaves with exposed rafters
• Either hipped or gabled tile roof
• Roof parapets
• Large square pillars or twisted columns
• Arched entry and windows with deep openings
• Covered walkways or arcades
• Round or quatrefoil window
• Restrained decorative elements usually consisting of tile, iron, and
wood
42
Eclectic Revival Styles: Dutch Colonial Revival
Background
Dutch Colonial Revival emerged as an architectural style in the United
States in the early 1900s and structures in this style in Los Angeles
generally date from the 1910s to the 1930s. The Dutch Colonial Revival
style is imitative of early Dutch Colonial buildings in the Northeastern
United States during the American Colonial period. One of the tenants
of the style is a gambrel roof that houses a full second story (this
originally emerged as a building type where second-story restrictions
prevented a full second fl oor). The Dutch Colonial Revival style is part
of the Revival or Romantic architectural movements that were popular
in the United States during the early 20th Century.
Common Characteristics of the Dutch Colonial Style
Dutch Colonial Revival structures are typically two-story, with a
gambrel roof, shallow eaves, and sometimes sport Dutch doors or half-
timbering. Windows are quite often arranged singularly, as are doors.
Porches tend to be diminutive in size and use simple square or round
columns. Some variants will incorporate Georgian entry features such
as pilasters and crowns surrounding the front door. Roofs are nearly
always gambrel, and side gables tend to be most widely used. Dutch
Colonial Revival features are often mixed with Colonial Revival or
Shingle styles.
General Characteristics
• 1½ to 2 stories
• Clapboard, shingle, stone or stucco siding
• Typically symmetrical façades, but also found with side entries
• Gable-end chimneys
• Round windows in gable end
• Porch under overhanging eaves with simple classical columns
• Multi-pane, double-hung windows
• Shed, hipped, or gable dormers
43
Preservation Plan
Eclectic Revival Styles: English Tudor Revival
(Also English Cottage, English Revival, Storybook Revival, etc.)
Background
A romanticized recreation of medieval English architecture, the English
Tudor Revival style found popularity in the United States in the 1890s
through the 1930s. In Los Angeles, the fi rst Tudor style buildings were
built in the early 1900s during the Arts and Crafts Period, though
the style continued on in popularity through the 1930s. A higher
concentration of English Tudor Revival structures were built during
the Eclectic Revival Period, though the style could also be considered an
Arts and Crafts Period style. Variations of this style include the English
Cottage, which typically includes an asymmetrical fl oor plan but without
the half timbering and heavy ornamentation and the playful Storybook
Style, which usually over-emphasizes features such as faux-thatched
roofs, roof pitch and whimsical ornamentation.
Common Characteristics of the English Tudor Revival Styles
English Tudor Revival structures are typically two or three stories, with
steeply pitched roofs, cross gables, and often have shingle or slate roofs
that attempt to replicate the look of medieval thatching. English cottage
structures will replicate this pattern, though they are often found in
single-story versions. English Tudor Revival structures nearly always
use half-timbering, stucco and masonry (often arranged in a herring
bone pattern, or using clinker bricks) while English Cottage structures
may simply be stucco. Windows tend to be arranged singularly, may
be casement or use hung sashes, and often utilize artful leaded glass
patterns. Chimneys are massive and integral to the overall look of the
house. Porches are minimal, and include simple archways and recesses.
Doors are usually singular and may be rectangular or arched.
The Tudor and English Revival styles features can be found mixed
Victorian era styles such as Queen Anne, Arts and Crafts Period
structures such as Craftsman, and with other Eclectic Revival period
styles such as French Eclectic.
General Characteristics
• One-and-one-half to two stories with asymmetrical and irregular
plan
• Cross-gabled, medium to steeply pitched roof, sometimes with clipped
gables
• Use of half-timbering, patterned masonry, stone and stucco
• Arrangements of tall, narrow windows in bands; small window
panes either double-hung or casement
• Over scaled chimneys with decorative brickwork and chimney pots
• Rectangular or arched doorways, often recessed or found within
tower features
44
Eclectic Revival Styles: Italian Renaissance Revival
Background
Italian Renaissance Revival buildings were popular in the United States
from the early 1900’s and surged in popularity in Los Angeles in the 1910’s.
Along with the rest of the Period Revival movement, Italian Renaissance
Revival draws upon romanticized notions of historic architectural motifs.
The Italian Renaissance Revival style is loosely based on Italian palazzos
of the sixteenth century. The style was usually used in particularly grand
homes and public buildings where an imposing presence was desired.
The style gained particular popularity in Los Angeles because it could
easily be integrated with other popular styles both within the Arts and
Crafts movement and the Eclectic Revival Movement. There are Italian
Renaissance Revival homes in LA that exhibit characteristics of the
Mission Revival and Craftsman styles as well as Mediterranean Revival
and Spanish Colonial Revival styles.
Common Characteristics of the Italian
Renaissance Revival Style
Italian Renaissance Revival homes usually have a low-pitched hipped
roof adorned with clay pantile and decorative edge features, elaborate
windows on the fi rst fl oor with a more simplifi ed window pattern on the
second, wide roof overhangs with decorative brackets, an emphasis on
arches, especially on the fi rst fl oor and are most often symmetrical.
Italian Renaissance Revival structures bear a close resemblance to their
Mediterranean Revival counterparts but can usually be distinguished
by a higher level of decorative detail, a stronger adherence to order
and symmetry and a full second fl oor. One must understand that while
Italian Renaissance Revival homes are inspired by Italian palazzos,
Mediterranean Revival homes are inspired by more rustic seaside villas
found throughout Mediterranean region.
General Characteristics
• Low pitched, hipped tile roof
• Pantiles in reds, greens and blues
• Moderate to wide eaves with decorative bracket supports
• Recessed porches with arched openings
• Classical detailing in use of columns, quoins, pediments, arches, and
pilasters
• Most often symmetrical
• Balanced wings
• Use of three-color palette with subdued and formal tones
45
Preservation Plan
Eclectic Revival Styles: Mediterranean Revival
Background
The Mediterranean Revival style is loosely based on Italian seaside
villas from the sixteenth century. The style was particularly prevalent
in Southern California, because of a popular association of the
California coast with Mediterranean resorts and because the original
Mediterranean structures were adapted to a climate not unlike
California’s. Though often used in massive and imposing structures,
style is somewhat free-fl owing, bereft of many of the classical elements
that adorn Italian Renaissance Revival counterparts. The fi rst
Mediterranean/Italian Renaissance Revival buildings were built in the
United States starting in the early 1900s. These styles became popular
in Los Angeles in the nineteen-teens.
Common Characteristics of the
Mediterranean Revival Style
Structures may be either symmetrical or asymmetrical, often
incorporate courtyards and garden walls, archways, arcades and
mosaic tile work. Roofs may be gabled or hipped, but are nearly always
adorned with clay tile or pantile. Windows are often deeply recessed
and may be grouped or singular and often use casements. Elements of
the Mediterranean Revival style can often be found mixed with Italian
Renaissance Revival, Beaux Arts and Spanish Colonial Revival styles.
General Characteristics
• Rectangular or irregular plans
• Varied, irregular roofs with simple eaves
• Arched and rectangular windows and doors
• Windows may be grouped or singular
• Balconies, patios and courtyards integrated into plan
• Entry often accentuated with decorative columns
• Clay tile roofs
• Vibrant two and three-color schemes with walls in shades
reminiscent of adobe
46
Eclectic Revival Styles: Monterey Revival
Background
The Monterey Revival style re-creation of the rustic American-
infl uenced Spanish Colonial houses of the Central Coast region of
California during the California colonial period of the 1840s. Monterey
buildings are a blend of Spanish Adobe construction fused with
American Colonial massing. The style emerged in popularity along
with various other Spanish and Mediterranean inspired styles in the
1920s.
Common Characteristics of the Monterey Revival Style
Monterey Revival style structures are two stories with different
cladding material for each fl oor, an ‘L’-shaped plan, a low-pitched
gabled roof and a cantilevered second fl oor balcony. Earlier versions
exhibit more Spanish Colonial detailing, while later versions contain
more colonial references such as shuttered windows and wood siding on
the upper or both fl oors. The Monterey Revival style is often combined
with Spanish Colonial Revival, Mediterranean Revival and Minimal
Traditional styles.
General Characteristics
• Cantilevered second-fl oor balcony at front elevation with simple
posts and railings
• Always two-stories with disparate building materials between fi rst
and second fl oor
• Low pitched side-gabled roof with clay tile or wood shingle
• Entrance adorned with pediments or crown, no porch
• Windows often adorned with shutters
• Rustic natural colors used on body with vibrant accent colors
47
Preservation Plan
Eclectic Revival Styles: Spanish Colonial Revival
Background
The Spanish Colonial Revival style grew out of a renewed interest in the
architecture the early Spanish colonies of North and South America.
The architectural features of this style are intended to refl ect the rustic
traditional Spanish architecture with local building materials such as
stucco, adobe, clay and tile. While the style can be closely tied to the
Mission Revival style, Spanish Colonial Revival is generally inspired
by the more formal buildings that were constructed during the colonial
area, whereas Mission Revival tends to be more rustic and holds more
closely to the design principles of the Arts and Crafts Movement. While
the differences may be minor when the subject is a small single family
house, larger Spanish Colonial Revival structures, such as churches,
institutional buildings or grandiose mansions tend to refl ect a higher
level of ornamentation and order. Structures that hold less closely
to the aesthetic of Spanish Colonial architecture may also be called
Spanish Eclectic.
Common Characteristics of the Spanish
Colonial Revival Style
Spanish Colonial structures are typically one or two stories and
rectangular in fl oor plan. The buildings have low-pitched tile roofs,
parapet roofs with tile coping, or some combination of the two; recessed
openings, decorative ironwork and decorative plaster reliefs. In its
simplest form, Spanish Colonial Revival structures are characterized
by white stucco or plaster exteriors, red tile roofs and arched window
or doorway openings. More elaborate examples incorporate jehas
and grilles of wood, wrought iron or plaster. It is not uncommon to
fi nd extensive use of terra cotta and glazed tile; balconies and patios.
Spanish Colonial buildings are often mixed with Mission Revival,
Mediterranean Revival, Moorish Revival, Monterey Revival and
Moderne styles.
General Characteristics
• Asymmetrical
• Low-pitched fl at, gable, or hip roof, typically with no overhang
• Clay tile roof
• Half round arches, doors, and windows
• Stucco over adobe brick, or adobe brick exterior walls
• Ornate tile, wrought iron, and wood work
• Formal plan with decorative plaster work
• Later variants using more whimsical plans with diminished
ornamentation
48
49
Preservation Plan
7.1 Introduction
Rehabilitation is the process of working on a historic structure or site
in a way that adapts it to modern life while respecting and preserving
the historic, character-defi ning elements that make the structure, site
or district important.
These Residential Rehabilitation Guidelines are intended for the
use of residential property owners and care-takers planning work
on Contributing structures or sites within the HPOZ. Contributing
structures are those structures, landscapes, natural features, or sites
identifi ed as contributing to the overall integrity of the HPOZ by the
Historic Resources Survey for the Western Heights HPOZ. Generally,
“Contributing” structures would have been built within the historic
period of signifi cance of the HPOZ, and will retain elements that identify
it as belonging to that period. The historic period of signifi cance of the
HPOZ is usually the time period in which the majority of construction
in the area occurred. In some instances, structures that are compatible
with the architecture of that period or that are historic in their own
right, but were built outside of the period of signifi cance of the district,
will also be “Contributing”.
The Residential Rehabilitation of the guidelines should be used in
planning, reviewing and executing projects for single-family structures
and most multi-family structures in residential areas. They are also
intended for use in the planning and review of projects or structures
that were originally built as residential structures but have since
been converted to commercial use. For instance, the Residential
Rehabilitation Guidelines would be used to plan work on a historic
structure built as a residence that is now used as a day-care facility.
The Residential Rehabilitation Guidelines are divided into ten (10)
sections, each of which discusses an element of the design of historic
structures and sites. If you are thinking about planning a project that
involves the area around your house, such as repaving your driveway
or building a fence, the “Setting” would be a good place to start. If you
are planning work on your roof, you might want to look back at Chapter
6, Architectural Styles to determine the style of the building and what
type of roof and roof materials are appropriate, and then at the “Roofs”
section here in Chapter 7 of these guidelines. The Table of Contents
details other sections that might pertain to your project.
While the Design Guidelines throughout this Preservation Plan are a
helpful tool for most projects, some types of work may not specifi cally
be discussed here. With this in mind, it is always appropriate to
remember that the Design Guidelines of this Preservation Plan have
been developed in concert with the Secretary of Interior’s Standards
for Rehabilitation, a set of standards used nationally for the review
of projects at historic sites and districts. All projects should comply
with the Secretary of Interior’s Standards, and where more specifi c
Chapter 7 Residential Rehabilitation
50
guidelines have been set for by this Preservation Plan, the guidelines
herein. The following principles are from the portions of the Secretary
of the Interior’s Standards that are applicable to HPOZ review, and are
the basic principles on which these guidelines are based:
Rehabilitation, maintenance, and modifi cation of design elements not
visible from the public right-of-way will generally not be required to be
held to strict guideline standards. However they will be evaluated to
ensure that materials are compatible, and that rhythm, scale, and style
are harmonious and appropriate to the original structure.
Principle 1:
The historic appearance of the HPOZ should be preserved. This
appearance includes both the structures and their setting.
Principle 2:
The historic appearance of contributing structures within the HPOZ
should be preserved. (The historic appearance of publicly visible facades
of contributing structures within the HPOZ should be preserved.)
Principle 3:
The historic fabric of contributing structures should be preserved.
Repair should be attempted before replacement.
Principle 4:
Replacement elements should match the original in materials, design,
and fi nish as closely as possible.
Principle 5:
If historic design elements have been lost, conjectural elements should
not be used. Every effort should be made to ascertain the original
appearance of the structure, and to replicate that appearance.
Principle 6:
New additions should be designed to be compatible with the massing,
size, scale, and architectural features of a historic structure or site,
while clearly refl ecting the modern origin of the addition. Additions
should be designed to preserve the signifi cant historic fabric of
contributing structures or sites.
51
Preservation Plan
Historic and mature trees provide
shade and establish an indelible part
of the neighborhood’s character.
Poured concrete steps and walkways are a
common feature in the neighborhood.
Historic retaining walls, often comprised of stone,
are an important part of the neighborhood setting.
7.2 Setting - Landscaping, Fences, Walls, Walks,
and Open Space
The site design of an historic structure is an essential part of its
character. This design includes the streetscape in which the site is set,
the planting strip along the street, setbacks, drives, walks, retaining
walls, the way a structure sits on its lot in relation to other structures and
the street, and other landscaping elements. While many of the historic
structures in the HPOZ may have lost some of these characteristics
over time, certain common characteristics remain which help to defi ne
the character of these historic areas and the structures within them.
Traditionally, residential structures were sited on their lots in a way
that emphasized a progression of public to private spaces. Streetscapes
led to planting strips, planting strips to sidewalks, sidewalks to yards
and front walkways, which led to porches and the private spaces
within a house. Residential structures were confi gured in such a way
that living space was oriented toward the front of the house and utility
spaces such as kitchens, service porches garages were most often
oriented toward the rear yard. Rear yards were most commonly used as
a utility space, keeping car parking, gardening, and household chores
to the privacy of an enclosed and private space. Common setbacks in
the front and side yards helped ensure these orderly progressions.
Preservation of these progressions is essential to the preservation of
the historic residential character of structures and neighborhoods.
Preservation of these progressions is often essential to the maintenance
of historic neighborhood streets as a functioning resource around which
a neighborhood interacts.
Guidelines
1. Mature trees and hedges, particularly street trees in the public
planting strip, should be retained whenever possible, or alternately
replaced with in-kind materials. Special attention should be paid
to historic tree planting patterns and species and efforts should be
made to re-introduce similar landscape elements on new plantings.
2. If historic plantings do exist, they should be preserved in their
original locations. If these features cannot be preserved, they
should be replaced in kind.
3. Historic topographic features should be preserved whenever
possible. Leveling or terracing a lot that was traditionally
characterized by a steep hillside or a terrace is not appropriate.
4. Historic sidewalks, walkways and other hardscape features should
be preserved. If these elements are replaced, they should be
replaced with materials similar to those historically present in the
area. Special attention should be paid to replicating score patterns,
pavement texture, swirl patterns and coloration.
52
5. If historic retaining walls, pathways, stairs or fences exist, they
should be rehabilitated or preserved in place. If they must be
removed, they should be replaced in kind. If reinforcement is
necessary, fi nish materials should match the original in materials
and design.
6. Painting unfi nished concrete, stone or masonry historic retaining
walls or garden walls is inappropriate.
7. When original site features have been lost and must be replaced,
designs should be based on historic photographic evidence. If no
such evidence exists, the design of replacement details should be
based on a combination of physical evidence and evidence of similar
elements found at similar properties in the HPOZ.
8. The traditional character of residential front and side yards should
be preserved. These areas should be reserved for planting materials
and lawn, and non-porous ground coverings should be minimized.
Excessive pavement within the front yard area is inappropriate.
9. The traditional character of multi-family residential front yards,
courtyards and other open areas should be preserved. These areas
should be reserved for planting materials and lawn, and non-porous
ground coverings should be minimized. Excessive pavement within
the front yard or courtyard areas is inappropriate.
10. The use of front yard areas or courtyards for car parking, storage
or other utility uses is generally inappropriate. Designated parking
areas and driveways should be located within the rear yard area and
should be screened from view of the general public by appropriate
fencing or planting strips.
11. Fencing and walls, where appropriate, should be comprised of
simple materials that are consistent with the Period of Signifi cance.
In most cases, front yard fencing is inappropriate, but low garden
walls that do not obstruct views of the home or the streetscape
may be appropriate in some locations. Rear yard fencing should
be visually unobtrusive to the general public. Materials such
as unfi nished concrete block or overly ornate wrought iron are
inappropriate.
12. Landscaping should not be so lush or massive that public views of
the house or streetscape are signifi cantly obstructed.
13. Gates and fences that enclose a rear yard should not completely
block views of building architectural details nor should they
completely enclose a porte-cochere or similar driveway feature.
14. Swimming pools should be confi ned to an enclosed rear yard.
Above-ground pools are generally inappropriate, as are excessively
massive pool accoutrements that would be visible to the general
public such as fountains, slides and waterfalls.
The fence arrangements in the middle two properties
fortify the entire yard, obscure views of the building’s
features and are considered inappropriate.
Parking pads should always be located to the rear.
Excessive front yard pavement is inappropriate.
53
Preservation Plan
Window types typical to historic homes are shown.
15. New physical features within a front yard, such as ponds, fountains,
gazebos, recreational equipment, sculptural elements, etc. are
generally discouraged. When appropriate, such features should be
diminutive in scale and style and visually deferential both to the
residential structure onsite and to similar physical features that
were constructed during the Period of Signifi cance.
16. Drought tolerant alternatives to traditional front yard lawns may
be found appropriate at some locations so long as such alternatives
are consistent with the prevailing character and appearance
of front yards in the neighborhood. In most cases front yards
in historic neighborhoods are green and open. A thoughtfully
prepared landscape plan using alternative low-water plant species
may replicate the desired greenness and openness. High-quality
artifi cial turf that allows for surface permeability and closely
resembles the look and texture of grass might also be found
appropriate for some locations.
17. In addition to compliance with the City’s sign regulations (LAMC
12.21 A 7), any signs used for a home-based business or church
structure in a residential area should be designed with sensitivity
for the historic context. Such signs should be minimal in size, should
not conceal any signifi cant architectural or landscape features, and
should be constructed of materials and colors that are appropriate
to the style of the house and the Period of Signifi cance. Illuminated
signs and digital signs are not permitted by the City in residential
areas and would be inappropriate in an HPOZ
7.3 Windows
Windows are an integral part of a historic structure’s design. The
placement of window openings on a façade, also known as fenestration,
the size of openings, and how openings are grouped, are all of great
importance. Of equal importance are the construction, material and
profi le of individual windows. Important defi ning features of a window
include the sill profi le, the height of the rails, the pattern of the panes
and muntins, the arrangement of the sashes, the depth of the jamb,
and the width and design of casing and the head. In some cases, the
color and texture of the glazing are also important.
Most windows found in Los Angeles’ Pre-WWII Historic Districts are
wood-frame true divided light windows. True divided light windows
have multiple panes of glass. These windows are usually double-hung,
fi xed, or casement style windows. Double-hung windows have operable
sashes that slide vertically. Casement windows open either outwards
or inwards away from the wall. In some areas, metal frame casement
or fi xed divided light windows are common. These windows range from
simple one-over-one windows to windows with panes in specialty shapes
or leaded and stained glass. In many Post-WWII Historic Districts
Low-water and native landscapes can be
lush and attractive and are well suited
to the Arts and Crafts period.
54
windows may use simpler materials such as metal frames, however the
placement of unique window features, such as fl oor-to-ceiling windows,
or unique glazing surfaces can require substantial consideration.
Inappropriate replacement of windows can compromise the integrity
of a building and have a serious negative effect on the character of a
structure. Generally, historic windows should not be replaced unless
they cannot be repaired or rebuilt. If windows must be replaced,
the replacement windows should match the originals in dimension,
material, confi guration and detail. Because it is often diffi cult to
fi nd off-the-shelf windows that will match historic windows in these
details, replacing historic windows appropriately often requires having
windows custom built.
Maintaining historic windows makes good economic sense, as they
will typically last much longer than modern replacement windows.
Problems with peeling paint, draftiness, sticking sashes, and loose
putty are all problems that are easy to repair. Changing a sash cord,
re-puttying a window, or waxing a window track are repairs that most
homeowners can accomplish on their own to extend the life of their
windows.
Guidelines
1. Repair windows and window hardware whenever possible instead
of replacing them. Special attention should be paid to materials,
hardware, method of construction and profi le.
2. When the replacement of windows is necessary, replacement
windows should match the historic windows in size, shape,
arrangement of panes, materials, hardware, method of construction
and profi le.
3. The historic pattern of windows on a façade, and the placement of
individual windows should be maintained. Fenestration patterns
on historic houses are generally most evident on front-facing
facades, secondary and non-visible facades may have less defi ned
fenestration patterns.
4. Adding new windows, fi lling-in historic windows, or altering the
size of historic windows on a street-visible facade is inappropriate.
5. Conjectural elements such as new decorative windows or window
ornamentation should be avoided if such features were not
originally part of the structure.
6. When altering window sizes or placement on non-street-visible
facades is of a minimal scope and can be found appropriate, care
should be taken so that new windows on historic facades should
match the rhythm and scale of the existing windows on the facade.
The basic anatomy of a double-
hung window is shown.
The modern windows that have been added to
this home are poorly scaled and dramatically
alter the home’s original appearance.
55
Preservation Plan
7. If a window is missing entirely, replace it with a new window in
the same design as the original if the original design is known.
If the design is not known, the design of the new window should
be compatible with the size of the opening, and the style of the
building.
8. Replacement windows on a non-street-visible facade may vary in
materials and method of construction from the historic windows,
although the arrangement of panes, size, and shape should be
similar.
9. The installation of ‘greenhouse’ type kitchen windows extending
beyond the plane of the facade is generally inappropriate.
10. Window screens should match the existing window trim in fi nish
color.
11. Awnings and shutters should be similar in materials, design, and
operation to those used historically, and should not be used on
architectural styles that do not normally use such features. When
they can be appropriately used, awnings should always conform to
the shape of the window on which they are installed.
12. Burglar or safety bars that are not original to the structure are
discouraged. In cases where bars may be found appropriate, such as
installation on a non-street-visible façade, bars should use minimal
ornamentation.
13. Bars or grillwork that is original to the structure should be retained.
14. In the interest of energy savings, alternative methods of weather-
proofi ng should be considered prior to consideration of the removal
of original windows. Methods such as wall, attic and roof insulation
or weather-stripping existing windows or the restoration of existing
windows may provide desired energy savings without the removal
of important historic features.
7.4 Doors
The pattern and design of doors are major defi ning features of a
structure. Changing these elements in an inappropriate manner has
a strong negative impact on the historic character of the structure and
the neighborhood. Doors defi ne character through their shape, size,
construction, glazing, embellishments, arrangement on the façade,
hardware, detail and materials, and profi le. In many cases doors were
further distinguished by the placement of surrounding sidelights,
fanlights, or other architectural detailing. Preservation of these
features is also important to the preservation of a house’s architectural
character.
Replacing or obscuring doors can have a serious negative effect on the
character of a structure. Generally, historic doors and their surrounds
A curved bay of double-hung windows is shown.
An inappropriately sized aluminum window
diminishes the historic value of a house.
Despite their utility, garden-box windows
such as this did not exist during this
home’s Period of Signifi cance.
56
should not be replaced unless they cannot be repaired or rebuilt. If
doors must be replaced, the replacement doors and their surrounds
should match the originals in dimension, material, confi guration and
detail. Because it is often diffi cult to fi nd standard doors that will match
historic doors in these details, replacing historic doors appropriately
often requires having doors custom built or requires searching for
appropriate doors at architectural salvage specialty stores.
Maintaining historic doors makes good economic sense, as they will
typically last much longer than modern replacement doors. Problems
with peeling paint, draftiness, sticking, and loose glazing, are all
problems that are often quite easy to repair. Applying weather
stripping, re-puttying a window, or sanding down the bottom of a door
are repairs that most homeowners can accomplish on their own.
Screened doors were often historically present on many houses, and
appropriately designed screened doors can still be obtained. However,
installing a metal security door which blocks your door from view is
inappropriate, and should be avoided.
Guidelines
1. Existing doors should be repaired when possible, rather than
replaced. Special attention should be paid to the materials and
design of historic doors and their surrounds.
2. The size, scale, and proportions of historic doors on a façade should
be maintained.
3. Filling in or altering the size of historic doors, especially on street-
visible facades, is inappropriate.
4. Adding doors to street-visible historic facades is inappropriate.
5. When replacement of doors is necessary, replacement doors should
match the historic doors in size, shape, scale, glazing, materials,
method of construction, and profi le.
6. When original doors have been lost and must be replaced, designs
should be based on historic photographic evidence. If no such
evidence exists, the design of replacement doors should be based on
a combination of physical evidence (indications in the structure of
the house itself) and evidence of similar doors on houses of the same
architectural style in the neighborhood.
7. Painting historic doors that were originally varnished or stained
and are not currently painted is not appropriate.
8. Original hardware, including visible hinges, doorknockers, and
latches or locks should not be removed. Repairing original hardware
is preferable; if replacing hardware is necessary, hardware that is
similar in design, materials, and scale should be used.
The anatomy of a Colonial Revival
style door is shown.
This doorway has been altered with a
metal gate and plate glass sidelights.
This Craftsman style door shows off a rustic wood
fi nish, original hardware and a rectilinear design.
57
Preservation Plan
Non-perminant devices such as this bamboo
screen may effectively screen a porch without
altering the home and disrupting the streetscape.
The components of a Craftsman
style porch are shown
9. Screen doors that are consistent with the architectural style and
compatible with the door size may be appropriate. Metal security
doors, especially on front doors are inappropriate.
10. In the interest of energy savings, alternative methods of weather-
proofi ng should be considered prior to consideration of the removal
of an original door. Methods such as wall, attic and roof insulation
or weather-stripping existing doors or lights within doors may
provide desired energy savings without the removal of important
historic features
7.5 Porches
Historically, residential porches in their many forms—stoops, porticos,
terraces, entrance courtyards, porte-cocheres, patios, or verandas—
served a variety of functions. They provided a sheltered outdoor living
space in the days before reliable climate controls, they defi ned a semi-
public area to help mediate between the public street areas and the
private area within the home, and they provided an architectural focus
to help defi ne entryways and allow for the development of architectural
detail.
Porch design, scale, and detail vary widely between architectural
styles. To help determine what elements are particularly important
on your porch, consult the architectural styles of these guidelines, or
contact your HPOZ board for a consultation
In addition to preservation benefi ts, retaining porches makes
economic sense, because the shade provided by a porch may greatly
reduce energy bills. Porch elements which have deteriorated due to
moisture or insect damage should be carefully examined to determine
if the entire element is unsalvageable. If only a part of the element is
damaged, then piecing in or patching may be a better solution than
removal and replacement. If replacement is necessary, the element to
be removed should be carefully documented through photos and careful
measurements before the element is discarded. Having these photos
and measurements will assist you in fi nding or making a replica of the
element you are replacing. When porch foundations fail, the underlying
cause is often ground subsidence or a build-up of moisture around the
foundation. In these cases, a careful analysis should be made to locate
the causes of the failure, and eliminate them as a part of the project.
Guidelines
1. Preserve historic porches in place and maintain their use as an
outdoor living space.
2. Preserve decorative details that help to defi ne an historic porch.
These may include balusters, balustrades, columns, and brackets.
58
Enclosing a front porch disrupts the porch’s
intended purpose as an outdoor room.
The porch, porte-cochere and balcony are a
prominant feature on this Tudor-Craftsman house.
Back porches and services porches may
beenclosed in sensitive and appropriate ways.
3. If porch elements are damaged, they should be repaired in place
wherever possible, instead of being removed and replaced.
4. If elements of the porch, such as decorative brackets or columns,
must be replaced, replacement materials should exactly match the
originals in design and materials.
5. When original details have been lost and must be replaced, designs
should be based on historic photographic evidence. If no such
evidence exists, the design of replacement details should be based
on a combination of physical evidence (indications in the structure
of the house itself) and evidence of similar elements on houses of
the same architectural style in the neighborhood.
6. Additional porch elements should not be added if they did not exist
historically. For instance, the addition of decorative “gingerbread”
brackets to a Craftsman-style porch is inappropriate.
7. In many instances, historic porches did not include balustrades,
and these should not be added unless there is evidence that a
balustrade existed on a porch historically.
8. The addition of a porch that would not have existed on a house
historically, such as an elaborate, highly detailed porch to the rear
of an historic structure, is strongly discouraged.
9. Enclosure of part or all of an historic porch is inappropriate.
10. Enclosure of a porch at the side or rear of the house, for instance a
sleeping porch, may be appropriate if the porch form is preserved
and the porch openings are fi tted with windows using reversible
construction techniques.
11. Alterations for handicapped access should be done at a side or rear
entrance whenever feasible, and should be designed and built in
the least intrusive manner possible using reversible construction
techniques.
12. Addition of a handrail on the front steps of a house for safety or
handicapped access reasons may be appropriate, if the handrail is
very simple in design.
59
Preservation Plan
Basic roof forms are shown.
Roof details may vary greatly depending
upon the architectural style.
Altering the basic form of a visible
roof is inappropriate.
7.6 Roofs
The roof is a major character-defi ning feature for most historic
structures. Similar roof forms repeated on a street help create a sense
of visual continuity for the neighborhood. Roof pitch, materials, size,
orientation, eave depth and confi guration, and roof decoration are all
distinct features that contribute to the overall integrity of an historic
roof. The location and design of chimneys as well as decorative features
such as dormers, vents and fi nials are also often character defi ning roof
features.
Certain roof forms and materials are strongly associated with particular
architectural styles; for instance, built-up faux thatch roofs are often
found on English Tudor Revival cottages. Consult the architectural
styles guide of these guidelines for more specifi c information about the
roof of your house.
Guidelines
1. Preserve the historic roof form. For instance, a complex roof plan
with many gables should not be simplifi ed.
2. Preserve the historic eave depth and confi guration.
3. Roof and eave details, such as rafter tails, vents, corbels, built in
gutters and other architectural features should be preserved. If
these elements have deteriorated, they should be repaired in place
if possible. If these elements cannot be repaired in place, match the
originals in design, materials, and details.
4. When original details have been lost and must be replaced, designs
should be based on historic photographic evidence. If no such
evidence exists, the design of replacement details should be based
on a combination of physical evidence (indications in the structure
of the house itself) and evidence of similar elements on houses of
the same architectural style in the neighborhood.
5. Historic specialty roofi ng materials, such as tile, slate, gravel or
built-up shingles, should be preserved in place or replaced in kind.
Wood roof shingles are no longer permissible in Los Angeles, and
where possible, special care should be taken to make minimal
repairs to wood shingle roofs rather than replace the roof outright.
6. Replacement roof materials, where in-kind replacement is not
possible, should convey a scale, texture, and color similar to those
used originally.
7. Light colored asphalt shingle is generally inappropriate. Earth
tones, such as rusty reds, greens, and browns, are generally
appropriate for asphalt shingle roofs.
60
Clay tile is an inappropraite material
for this Craftsman style home.
Ionic column details are shown on
this Classical Revival building.
8. Skylights or solar panels should be designed and placed in such as
way as to minimize their impact. Locations on the side and rear
facades are preferred for skylights. Where skylights are found
appropriate, the should be fl at and relatively fl ush to the roof
surface.
9. Existing chimney massing, details, and fi nishes should be retained.
Modern spark-arrestors or other similar devices should be hidden
within the chimney to the best extent feasible.
10. Existing roof dormers should not be removed on visible facades.
New roof dormers should not be added to visible facades.
7.7 Architectural Details
Architectural details showcase superior craftsmanship and
architectural design, add visual interest, and distinguish certain
building styles and types. Features such as lintels, brackets, and
columns were constructed with materials and fi nishes that are
associated with particular styles, and are character-defi ning features
as well. Determining the architectural style of your house can help you
to understand the importance of the related architectural details of
your house. The architectural styles of these guidelines, or your HPOZ
board, can help you determine what architectural details existed
historically on your house.
Decorative details should be maintained and repaired in a manner that
enhances their inherent qualities and maintains as much as possible
of their original character. A regular inspection and maintenance
program involving cleaning, and painting will help to keep problems
to a minimum. Repair of deteriorated architectural detail may
involve selective replacement of portions in kind, or it may involve
the application of an epoxy consolidant to stabilize the deteriorated
portion in place. These options should be carefully considered before
architectural detail is replaced, since matching architectural details
often requires paying a fi nish carpenter or metalworker to replicate a
particular element, which can be a major expense.
Guidelines
1. Preserve original architectural features. Deteriorated materials
or features should be repaired in place, if possible. For instance,
deteriorated wood details can be repaired with wood fi ller or epoxy
in many cases.
2. When it is necessary to replace materials or features due to
deterioration, replacement should be in kind, matching materials,
texture and design.
61
Preservation Plan
Foam plant-ons and pre-cast concrete
are materials that would not have been
originally used on this historic house.
Stone and masonry should always be left to exhibit
their natural fi nish qualities. Painting over the Arroyo
stone on this house has muted the stone’s texture.
3. When original details have been lost and must be replaced, designs
should be based on historic photographic evidence. If no such
evidence exists, the design of replacement details should be based
on a combination of physical evidence (indications in the structure
of the house itself) and evidence of similar elements on houses of
the same architectural style in the neighborhood.
4. Materials, such as masonry, which were not originally painted or
sealed, should remain unpainted.
5. Original building materials and details should not be covered
with inappropriate materials such as stucco, vinyl siding, or other
materials.
6. Architectural detail that did not originally appear on a structure
should not be added to a structure. For example, decorative spindle
work should not be added to a Craftsman-style balcony.
7. Decorative detail that is expressed through the pattern of materials
used in the construction of the house, such as decorative shingles
or masonry patterns, should be preserved or replaced in kind.
Covering or painting these details in a manner that obscures these
patterns is inappropriate.
7.8 Building Materials and Finishes
The characteristics of primary building materials, including the
scale of units that the materials are used and the texture and fi nish
of the material, contribute to the historic character of a building. For
example, the scale of wood shingle siding is so distinctive from the
early Craftsman period, it plays an important role in establishing the
scale and character of these historic buildings. In a similar way, the
color and fi nish of historic stucco is an important feature of Mission
Revival homes.
Before you replace exterior building materials, make sure that
replacement is necessary. In many cases, patching in with repair
materials is all that is needed. For instance, warped wooden clapboards
or shingles can be removed, and new materials can be pieced in.
Sometimes, epoxy or similar fi ller can be used to repair small areas
of damage. Replacement of deteriorated building materials requires
careful attention to the scale, texture, pattern, and detail of the
original material. The three-dimensionality of wood moldings and trim,
the distinctive texture of weatherboards, and the bonding pattern of
masonry walls are all important to duplicate when replacement is
necessary. When repairing or refreshing stucco fi nishes, it is important
to understand the role the texture of the stucco fi nish plays in the design
of the structure. Different architectural styles were characterized by
different fi nishes, and care should be taken to replicate the original
fi nish when stucco work is needed. Replacing or concealing exterior wall
This house has recently been emancipated
from a layer of stucco exposing ornate
and beautiful materials.
62
Wood siding comes in a variety of textures
and types. One size does not fi t all.
The sandstone porch columns are left to
display their natural fi nish quality.
Smooth, hand-trowled stucco is an approprate
fi nish for this Italian Renaissance Revival home.
materials with substitute materials is not appropriate. For example,
placing synthetic siding or stucco over original materials results in a
loss of original fabric, texture, and detail. In addition, such surfaces
may conceal moisture or termite damage or other causes of structural
deterioration from view.
Guidelines
1. Original building materials should be preserved whenever
possible.
2. Repairs through consolidation or “patching in” are preferred to
replacement.
3. If replacement is necessary, replacement materials should match
the original in material, scale, fi nish, details, profi le, and texture.
4. Building materials not originally painted should not be painted.
5. Original building materials should not be covered with vinyl,
stucco, or other fi nishes.
6. If resurfacing of a stucco surface is necessary, the surface applied
should match the original in texture and fi nish.
7. In choosing paint or stain colors, one should reference the
Architectural Styles Chapter to learn more about appropriate
paint colors and application. Stain or paint color choices should be
selected appropriate to the architectural period or style and care
should be take to address how various elements of the structure,
for instance the body, trim and accents will be painted.
8. In most cases, exterior paint should have a matte fi nish, not glossy
or semi-gloss.
7.9 Mechanicals
The usefulness of historic structures in the modern world is often
increased by updating these structures with modern heating and
cooling systems, electrical systems, satellite television or broadband
internet systems, solar panels, and other mechanical appurtenances
that require the location of equipment outside of the historic structure
itself. While the location of one of these elements may not seem to
make a signifi cant negative impact on a structure or neighborhood,
the visible location of many of these elements along the streetscape
can have a signifi cant negative effect on the historic character of a
neighborhood.
With careful planning, many mechanical appurtenances can be located
where they cannot be seen from the public way. Air conditioning units
can be placed in the rear yard or through rear windows. Attic vents
can be placed on the rear elevations of a roof, or in a rear dormer.
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Preservation Plan
Solar panels are best located
outside of the line of sight.
Satellite television dishes can usually be placed in the rear yard or
on a rear elevation of the roof. Junction boxes can be placed on rear
facades. Wiring for cable or telephone equipment or electrical lines
can be run through the interior walls of a structure instead of along
visible facades.
Even when mechanical equipment must be placed in a visible location
in the side or front yards, landscaping or paint treatments can help to
conceal these incompatible elements.
Guidelines
1. Satellite television dishes and other mechanical appurtenances
should be located in the rear yard, in a location not visible
from the public way, whenever possible. Small dishes or other
appurtenances (under 2’ in diameter) may be located on lower rear
roof surfaces, on rear yard accessory structures, on rear facades,
or in the rear yard.
2. Mechanical appurtenances that are physically mounted on an
historic structure must be attached using the least invasive
method, without damaging signifi cant architectural features.
3. Mechanical apparatus not mounted on the structure should be
located in rear or side yard areas not visible from the public way
whenever possible. In addition, consider placing such apparatus
out of sight and sound of neighboring homes, if at all possible.
4. Mechanical apparatus not mounted on the structure may be
installed in areas visible from the public way if there is no other
technically and economically feasible location for installation and
if appropriate landscape screening is proposed and installed as a
part of the project.
5. Mechanical apparatus that must be placed in a location potentially
visible from the public way should be obscured from view where
possible, including the use of landscape screening and the use of
paint colors to match the surrounding environment.
6. Utilities should be placed underground where feasible.
7. Electrical masts, headers, and fuse boxes should be located at the
rear of a structure where possible.
8. Solar panels should not be placed upon rooftops that are visible
to the general public. Location upon detached garages in many
instances will be appropriate, or upon rear-facing roofs that are
minimally visible from a public street. Solar panels should be low
in profi le, and should not overhang or alter existing roofl ines.
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Preservation Plan
8.1 Introduction
Few things can alter the appearance of a historic structure more quickly
than an ill-planned addition. Additions can not only radically change
the appearance of a structure to passersby, but can also result in the
destruction of much of the signifi cant historic material in the original
structure. New additions within an HPOZ are appropriate, as long as
they do not destroy signifi cant historic features, or materials, and are
compatible with both the neighborhood and the building to which they
are attached.
Careful planning of additions will allow for the adaptation of historic
structures to the demands of the current owner, while preserving their
historic character and materials.
The purpose of this is to ensure that the scale, height, bulk and massing
of attached additions on main and secondary structures is compatible
with the existing context of the historic structure and compatible with
the other “contributing structures in the neighborhood”, as viewed
from the street.
8.2 Additions to Primary Structures
While additions to primary structures may be appropriate, special
care should be taken to ensure that the addition does not disrupt the
prevailing architectural character of the district or of the structure
itself. Additions that are small in size, located to the rear of existing
structures, and that replicate existing building patterns such as
roof forms and fenestration, tend to be more successful than those
that do not. Great care should be taken with additions so as not to
communicate a false sense of history within the district with respect
to the size and arrangement of structures. For example, a massive
second-story addition that maximizes buildable fl oor area on a single
story Craftsman bungalow in a district comprised of similarly sized
single-story Craftsman bungalows would be inappropriate regardless
of whether or not the addition is adorned with historic appearing
architectural features.
Guidelines
1. Additions should be located at the rear of the structure, away from
the street-facing architectural façade.
2. Additions that break the plane established by the existing roofl ine
or side facades of the house are discouraged.
3. Additions that comprise a new fl oor (for instance a new second
fl oor on a single-story house) are discouraged. Where additions
that comprise a new fl oor can be found appropriate, such additions
should be located to the rear of the structure.
Chapter 8 Residential Additions
This second-story addition is set-back and preserves
the look and scale of the original bungalow.
Appropriate locations for additions will generally
not disrupt the front visible facades, or the overall
mass and character of the original structure.
This second-story addition, with its
noticable dormers, calls attention to itself,
overwhelming the original cottage.
66
4. Additions should use similar fi nish materials and fenestration
patterns as the original structure. A stucco addition to a wood
clapboard house, for example, would be inappropriate.
5. Additions should utilize roof forms that are consistent with the
existing house to the greatest extent possible, but should be
differentiated by virtue of scale and volume. Attention should be
paid to eave depth and roof pitch replicating these to the greatest
extent possible.
6. The original roofl ines of the front facade of a structure should
remain readable and not be obscured by an addition.
7. Additions should distinguish themselves from the original
structure through the simplifi ed use of architectural detail, or
through building massing or subtle variations of exterior fi nishes
to communicate that the addition is new construction.
8. The enclosure of rear porches, when found to be appropriate, should
preserve the overall look of the porch to the greatest extent possible
with respect to railings, balusters, openings and roofs.
9. Additions should utilize fenestration patterns that are consistent
with the existing house to the greatest extent possible, though
simplifi ed window types may be an appropriate means to
differentiate the addition from the original structure. For instance,
if windows on the original structure are multi-pane 8-over-1 light
windows, simple 1-over-1 light windows may be appropriate.
10. Additions should be subordinate in scale and volume to the existing
house. Additions that involve more than a 50% increase in the
ground fl oor plate are generally inappropriate.
11. Additions that extend the existing side facades rearward are
discouraged. Additions should be stepped-in from the side facade.
12. Decorative architectural features established on the existing house
should be repeated with less detail on the addition. Exact replicas
of features such as corbels, pilasters, decorative windows etc. are
inappropriate.
13. Additions that would necessitate the elimination of signifi cant
architectural features such as chimneys, decorative windows,
architectural symmetry or other impacts to the existing house are
not appropriate
14. Additions that would involve the removal or diminishment of open
areas on Multi-family properties, such as the infi ll of a courtyard to
be used for fl oor area, are in appropriate.
15. Additions that would require the location of designated parking
areas within the front yard area are inappropriate.
This addition looms over its neighbors and disrupts
the charm of a single-story bungalow neighborhood.
This addition disrupts the roof patternand
unique features of the home.
Additions should avoid breaking the side-
plane and roof-plane of the existing house.
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Preservation Plan
8.3 New Accessory Structures and Additions
to Existing Secondary Structures
Garages and accessory structures can make an important contribution
to the character of an historic neighborhood. Although high style
“carriage houses” did exist historically, garages and other accessory
structures were typically relatively simple structures architecturally,
with little decorative detail. Quite often these structures refl ected a
simplifi ed version of the architectural style of the house itself, and
were fi nished in similar materials.
Unfortunately, many historic garages and accessory structures have
not survived to the present day, perhaps because the structures
were often built fl ush with the ground, without a raised foundation.
Therefore, many homeowners in historic areas may need to confront
the issue of designing a new secondary structure.
For the rehabilitation of existing garages and accessory structures,
follow the same guidelines throughout this as you would for the
rehabilitation of a residential structure. The guidelines in this section
are specifi cally targeted towards the addition or reconstruction of
accessory structures on historic properties. It will also be useful to
consult the Setting guidelines of this Plan to determine the placement,
dimensions, and massing of such structures on lots with existing
historic buildings.
Guidelines
1. New accessory structures and garages should be similar in
character to those which historically existed in the area.
2. Basic rectangular roof forms, such as hipped or gabled roofs, are
appropriate for most garages.
3. New garages or accessory structures should be designed not to
compete visually with the historic residence.
4. Detached garages are preferred. Attached garages, when found to
be appropriate should be located to the rear of the house unless the
HPOZ consists of homes that have a preponderance of street-facing
garages.
5. New garages should be located behind the line of the rear wall of
the house whenever possible.
6. New accessory structures, such as greenhouses, porches or gazebos
should not take up more than 50% of the available back yard area.
7. Single-bay garage doors are more appropriate than double-bay
garage doors on most historic properties.
Many historic neighborhoods were
built with accessory living quarters over
garages. Attention should be paid to the
historic precedent on your street.
This in-fi ll accessory structure is
diminutive to its primary structure.
In many cases second stories can more gracefully be
accommodated as attics than full second stories.
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8. Second fl oor additions to garages or carriage houses, when found to
be appropriate, should not be larger than the length and width of a
standard three-car garage.
9. Accessory structures should always be diminutive in height, width
and area in comparison to the existing primary structure.
10. Accessory structures should replicate the architectural style of
the existing house with respect to materials, fenestration, roof
patterns etc., though architectural details such as corbels, pilasters
or molding should be replicated with less detail on accessory
structures.
11. Modifi cations to existing garages, carriage houses or accessory
structures that would involve a loss of signifi cant architectural
details pursuant to the Rehabilitation Guidelines should be
avoided. Special attention should be paid to preserving existing
historic garage doors where they exist.
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Preservation Plan
9.1 Introduction
“Infi ll” is the process of building a new structure on a vacant site within
an existing neighborhood. These Infi ll guidelines are also applicable to
the review of alterations to structures or sites within the HPOZ that
are “Non-Contributing” as identifi ed in the Historic Resource Survey.
These Residential Infi ll Guidelines are intended for the use of
residential property owners planning new structures on vacant sites
or alterations to Non-Contributing structures or sites within the
HPOZ. These guidelines help ensure that such new construction and
alterations recognize and are sensitive to their historic context.
Non-Contributing structures are those structures, landscapes, natural
features, or sites identifi ed as Non-Contributing in the Historic
Resources Survey for this HPOZ. Generally, Non-Contributing
structures are those that have been built outside of the historic period
of signifi cance of the HPOZ, or are those that were built within that
period but no longer retain the features (due to subsequent alterations)
that identify them as belonging to that period. The historic period
of signifi cance of the HPOZ is usually the time period in which the
majority of construction in the area occurred.
The Residential Infi ll Guidelines are divided into six (6) sections, each
covering a building design element. Elements from all sections will be
important when planning or evaluating proposed new construction
or alterations to existing non-contributing structures or sites. The
Residential Infi ll of the guidelines should be used in the planning and
review of most projects involving new structures in residential areas.
They are also intended for use in the planning and review of projects
for structures in areas that were originally built as residential areas
which have since been converted to commercial use.
9.2 The Design Approach
In addition to following these guidelines, successful new construction
shall take cues from its context and surroundings. One of the fi rst
steps in designing a new building within an historic district is to look
at other buildings on the block, and other similar buildings in the
neighborhood. In general, new construction should not try to exactly
replicate the style of the surrounding historic structures. However, it
is important that the design of new construction in an historic district
be consistent with the design of surrounding historic structures and
sites. Design elements that are usually important in establishing this
consistency include orientation on a site; massing and scale; roof form;
materials and the patterns of doors and windows.
Most HPOZs have stood the test of time because they contain structures
that are designed and constructed with a high level of design integrity
and quality of workmanship. Consequently, new structures within
Chapter 9 Residential Infi ll
70
the HPOZ should strive to integrate the highest and best design and
construction practices while integrating such elements into a program
that is well suited for the historic context.
Single Family Housing
Different architectural styles or types generally exhibit common
architectural design elements. Therefore, if you are considering a
project that involves new construction on a vacant lot, the fi rst step
in designing a new building is to determine what style elements are
present in other building on the block. If the existing buildings are all
of the same or similar styles, common design themes should emerge.
Do the majority of structures on your street have large front porches?
Parapet roofs? Wood cladding? The Residential Infi ll Guidelines that
follow point out various design elements that need special attention to
insure that new construction is compatible with the historic streetscape.
Contemporary designs for new in-fi ll construction are not necessarily
discouraged within the HPOZ. Most importantly, each project should
respond to its surrounding context and help to create a seamless
transition from architectural style to architectural style and from
building type to building type.
Multi-family Housing
Many HPOZs contain multi-family structures that were constructed
during their Period of Signifi cance. These may include a variety of
building types, including large apartment buildings, garden-style
apartment buildings, bungalow courts, or secondary dwelling units in
a rear yard. In some instances, single family homes were divided into
boarding houses or apartments during the Period of Signifi cance, and
those modifi cations may have historical signifi cance. Other HPOZs
would have originally consisted of single family homes, but beyond
the Period of Signifi cance, land use patterns and zoning regulations
may have allowed for multi-family uses. Houses may have been
converted to multi-family residences, or newer apartment or condo
buildings may have been constructed. In any event, when a multi-
family residential project is proposed in an HPOZ the project should
follow the Residential Infi ll Guidelines contained in this section. The
In-Fill Guidelines contain examples of several multi-family building
types and architectural styles that may be compatible with the HPOZ.
When possible, applicants should pay close attention to what types
of multi-family structures existed in the HPOZ during the Period of
Signifi cance.
The Residential Duplex/Triplex/Fourplex
In the period when many of Los Angeles’ HPOZs developed, low
density multi-family structures in residential neighborhoods often
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Preservation Plan
were developed in the same architectural styles and with similar
massing as single-family residences in the same area. The Craftsman
and Renaissance Revival styles, in particular, lent themselves to the
development of 2-unit to 4-unit structures, often with simple rectangular
massing. Usually, the only external indication that these structures
were not single family dwellings was the multi-door entryway, often
designed with the same porch form as single family neighbors.
These multi-family structures were usually developed with the
same setbacks, height, and often the same roof-forms as their
neighbors. In some cases, individual entryways were concealed
in a foyer or lobby beyond a common entry door, rendering these
structures indistinguishable from single-family residences in the
same neighborhood. In historic residential neighborhoods composed
primarily of two-story single-family structures, this architectural style
may be a useful model for low-density multi-family development.
Guidelines for building in the Duplex/Triplex/Fourplex form:
1. The scale, roof form and architectural style of the structure should
be consistent with these residential infi ll guidelines and with
surrounding historic residential structures.
2. Entryways should be located on the street-facing facade of the
structure, and should be designed to read as a single entryway.
This may be achieved through the location of doorways around
a central recessed entry, or through the use of a single exterior
doorway leading to an interior entry hall.
3. Entryways should be defi ned by a single traditional-styled porch.
4. Parking areas should be located to the rear of the structure.
5. Front yard areas should be comprised of landscaping. paving front
yard areas is inappropriate.
6. Setbacks should be consistent with surrounding historic single-
family structures.
The Bungalow Court
A low-scale multi-family housing solution popular in the pre-World
War II era, bungalow courts were classically composed as a cluster of
small one story residential structures of a common architectural style
organized, usually in two parallel lines, around a central courtyard
arranged perpendicular to the street, and often anchored by a two story
complex at the back of the courtyard.
Important elements of this design style that ensure its compatibility
with historic residential development patterns include the small
scale of the bungalows, the quality of their architectural detailing,
72
the choice of an architectural style compatible with surrounding
residential development, and a treatment of the facades on the
bungalows facing the primary street that includes details like porches,
entryways, overhanging eaves and other details which emphasize
reliance on traditional single-family residential design elements. This
type of development may be appropriate in historic areas composed
predominantly of small single story cottages or duplexes where multi-
family development is permitted by the zoning code.
Guidelines for building in the Bungalow Court form:
1. All buildings within the court should be designed in a cohesive
architectural style that refl ects an architectural style common in
the surrounding neighborhood.
2. Entryways within the court should be marked by porches that face
onto a central courtyard.
3. The central courtyard should be arranged perpendicular to the
street, with a central axial path leading through the development.
The central courtyard should not be sectioned off into private open
space.
4. The scale of the bungalows should refl ect the scale of the surrounding
historic residential structures.
The Courtyard Apartment Building
Courtyard apartments were a popular multi-family housing style in
Los Angeles from the 1920s-1950s. Typically, these complexes were
designed as two-story L or U shaped structures or clusters of structures
that wrapped around a central entry courtyard. These complexes were
typically built in a romantic style, often Spanish Colonial Revival or
Mediterranean Revival. Later examples were often built in the Early
Modern styles such as Streamline Moderne or Minimal Traditional.
The defi ning feature of these complexes is the central courtyard,
which was typically the central entryway to individual apartments.
Complexes with an L-shaped plan were typically designed in a smaller
scale, with individual exterior entryways for each unit. Quite often,
in these structures second-story entryways were designed as romantic
balconies or loggias. Quite often, the street-facing end of the L was
marked with large, elaborate windows.
In the U shaped variant of this style, the central courtyard typically
led to a central entryway, and each unit was accessed from an interior
hallway. These U shaped structures sometimes rose to three stories or
higher.
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Preservation Plan
The setting is characterized by a transition
from public to private space.
Guidelines for building in the Courtyard Apartment form:
1. New Courtyard Apartment structures should refl ect the scale of
surrounding historic residential structures.
2. Structures should be arranged on their lots in an L or U shape
around a central courtyard which is open to the street.
3. Lower scale structures may have individual exterior entryways
for each unit. These entryways should each be marked by its own
porch. Common balconies or porches spanning more than two
entryways are discouraged.
4. The central courtyard area should be extensively landscaped.
Water features and fountains are encouraged.
5. The architectural style and materials of the new structure should
refl ect an architectural style appropriate to the surrounding
historic area.
6. Parking areas should be located to the rear or beneath the structure.
9.3 Setting, Location and Site Design
The site design of an historic structure is an essential part of its
character. Further, the spacing and location of historic structures within
an historic neighborhood usually establishes a rhythm that is essential
to the character of the neighborhood. While each individual house
within an HPOZ may not be architecturally signifi cant in its own right,
the grouping of houses, with uniform setbacks and street features, give
the neighborhood a strong sense of place that is indeed signifi cant. The
early designers and builders of the HPOZ considered the streetscape,
setbacks, drives, walks, retaining walls, and the way a structure itself
sits on its lot in relation so others on the street. The purpose of this is
to provide guidelines that ensure that new construction visible from
the street respects and complements the existing historic streetscape.
Traditionally, residential structures were sited on their lots in a way
that emphasized a progression of public to private spaces: public streets,
planting strips (or parkways), sidewalks, front yard and front walks,
porches and, fi nally, the private space of an individual home. Nearly
all historic residential structures were designed to present their face to
the street, and not to a side or rear yard. This paradigm dictated that
spaces such as living rooms, dining rooms and parlors were generally
found at the front of houses whereas spaces such as kitchens, service
areas and detached garages were found at the rear. Common setbacks
in the front and side yards and appropriate fl oor-planning helped
ensure these orderly progressions. Preservation of these progressions
is essential to the preservation of the historic residential character of
structures and neighborhoods.
74
New houses should replicate the basic orientation
and arrangement of uses on the lot. Garages
located in the front are inappropriate.
Houses of varying styles and periods may
co-exist harmoniously by virtue of their
similar massing and orientation.
Guidelines
1. New residential structures should be placed on their lots to
harmonize with the existing historic setbacks of the block on which
they are located. The depth of the front and side yards should be
preserved, consistent with other structures on the same block face.
2. A progression of public to private spaces from the street to the
residence should be maintained. One method of achieving this goal
is to maintain the use of a porch to create a transitional space from
public to private.
3. Historic topography and continuity of grade between properties
should be maintained.
4. Attached garages are generally inappropriate; detached garages
are preferred. Garages should be located to the rear of the property.
5. Parking areas should be located to rear of a structure. Designation of
parking spaces within a front yard area is generally inappropriate.
6. Front and side yard areas should be largely dedicated to
planting areas. Large expanses of concrete and parking areas are
inappropriate.
7. The lot coverage proposed for an in-fi ll project should be substantially
consistent with the lot coverage of nearby Contributor properties.
9.4 Massing and Orientation
The height and massing of historic structures in an intact historic
neighborhood is most often fairly uniform along a block face. Nearly
all historic residential structures were designed to present their face to
the street, and not to a side or rear yard. The purpose of this section is
to ensure that the scale, height, bulk, and massing of new construction
visible from the street is compatible with the existing context of historic
structures and the neighborhood as a whole.
Guidelines
1. New residential structures should harmonize in scale and massing
with the existing historic structures in surrounding blocks. For
instance, a 2.5 story structure should not be built in a block largely
occupied by single-story bungalows.
2. When found to be appropriate, new structures that will be larger
than their neighbors should be designed in modules, with the
greater part of the mass located away from the main facade to
minimize the perceived bulk of the structure.
75
Preservation Plan
The in-fi ll example shown ignores the setback
and entrance orientation of its neighbors.
This street presents a consistent roof pattern
that should be replicated on new construction.
The in-fi ll example shown here ignores the
complex gable patterns of its neighbors.
3. New residential structures should present their front door and
major architectural facades to the primary street and not to the
side or rear yard.
4. In some cases on corner lots, a corner entryway between two defi ning
architectural facades may be appropriate.
5. A progression of public to private spaces in the front yard is
encouraged. One method of achieving this goal is through the use of
a porch to defi ne the primary entryway.
9.5 Roof Forms
It is often true that the structures on one block of an historic neighborhood
share a common architectural style. This common style frequently is
articulated by a common roof form, which helps establish a common
character for the block. The purpose of this is to encourage traditional
roof forms on infi ll houses in order to help maintain a common character
for the area.
Guidelines
1. New residential structures should echo the roof forms of the
surrounding historic structures. For instance, if the majority of
structures along a particular street utilize front-facing gable-ends,
the in-fi ll structure should likewise utilize a gable-end. Where a
diversity of roof forms exist on a street, a predominant form should
be used. It would be inappropriate to introduce a new roof form that
is not present on the street.
2. Roofi ng materials should appear similar to those used traditionally
in surrounding historic residential structures. If modern materials
are to be used, such materials should be simple and innocuous.
3. Dormers, and other roof features on new construction should echo
the size and placement of such features on historic structures
within the HPOZ.
4. In HPOZs where roof edge details, such as corbels, rafter tails,
or decorative vergeboards are common, new construction should
incorporate roof edge details which echo these traditional details in
a simplifi ed form.
76
Though different in style, this house’s deep, and
vertical openings help it to blend with its neighbors.
Flush, frameless, and oddly arranged windows
may be inappropriate on a new house.
9.6 Openings
The pattern of windows, doors, and other openings on the facades of
an historic structure strongly defi ne the character of the structure’s
design. These openings defi ne character through their shape, size,
construction, façade arrangement, materials, and profi le. Repetition of
these patterns in the many historic structures of an historic district
helps to defi ne the distinctive historic character of the area. It is
important, therefore, that new construction in these areas refl ect these
basic historic design patterns.
Guidelines
1. New construction should have a similar façade solid-to-void ratio to
those found in surrounding historic structures.
2. New construction should use similar window groupings and
alignments to those on surrounding historic structures.
3. Windows should be similar in shape and scale to those found in
surrounding historic structures.
4. Windows should appear similar in materials and construction to
those found in surrounding historic structures.
5. Dormers should be similar in scale to those found on existing
historic structures in the area.
6. Main entryways should be confi gured and emphasized similarly to
those on surrounding structures. Attention should be paid to design
similarities such as symmetry, depth, and the use of architectural
features such as pediments, crowns, porches, etc.
7. Entrance enclosures, such as porches, porte-cocheres and overhangs
should be used when similar features are widely used within the
neighborhood.
9.7 Materials and Details
Traditionally, the materials used to form the major facades of a residential
structure were intended to work in harmony with the architectural
detail of the building to present a unifi ed architectural style. Often,
this style is repeated with subtle variations on many structures within
an historic district. It is essential that new construction within an
historic area refl ect the character of the area by refl ecting the palette of
materials and design details historically present in the neighborhood.
77
Preservation Plan
Gaudy and conjectural features can cause
a house to stand out rather than fi nd
compatibilty with a historic neighborhood.
This home is being relocated to
an HPOZ in Pico-Union.
Though innovative and interesting, the
materials on this home do not relate to
those used in its surroundings.
Guidelines
1. New construction should incorporate materials similar to those
used traditionally in historic structures in the area. If most houses
within a neighborhood are wood clapboard, an in-fi ll house that is
entirely stucco is generally inappropriate.
2. Materials used in new construction should be in units similar in
scale to those used historically. For instance, bricks or masonry
units should be of the same size as those used historically.
3. Architectural details such a newel posts, porch columns, rafter tails,
etc., should echo, but not exactly imitate, architectural details on
surrounding historic structures. Special attention should be paid
to scale and arrangement, and, to a lesser extent, detail.
4. Use of simplifi ed versions of traditional architectural details is
encouraged.
5. If the integration of modern building materials, not present
during the Period of Signifi cance, is found to be appropriate, such
materials should be subtly used and appear visually innocuous in
comparison to surrounding historic structures.
9.8 Relocating Historic Structures
In most cases, the proposed relocation of an historic structure to a
location within an historic district should be evaluated in much the
same way as a proposed new infi ll construction project. There are,
however, several additional considerations that should be taken into
account when evaluating this type of project to ensure that the historic
importance of both the structure to be moved and the district in which
it will be relocated are preserved.
Guidelines
1. If feasible, relocation of a structure within its original neighborhood
is strongly preferred.
2. Relocation of the structure to a lot similar in size and topography
to the original is strongly preferred.
3. Generally, the structure to be relocated should be similar in age,
style, massing, and size to existing historic structures on the block
front on which it will be placed.
4. The structure to be relocated should be placed on its new lot in the
same orientation and with the same setbacks to the street as its
placement on its original lot.
5. A relocation plan should be prepared prior to relocation that
ensures that the least destructive method of relocation will be used.
78
6. Alterations to the historic structure proposed to further the
relocation process should be evaluated in accordance with the
Rehabilitation Guidelines.
7. The appearance, including materials and height of the new
foundations for the relocated historic structure should match those
original to the structure as closely as possible, taking into account
applicable codes.
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Preservation Plan
Existing street markers are a signifi cant
piece of the neighborhood’s history.
Retaining walls are an important part
of the neighborhood streetscape.
Sidewalk widths, parkway landscaping and
sidewalk score patterns should all be preserved.
12.1 Introduction
Along with private residential and commercial buildings and spaces,
public spaces and buildings also contribute to the unique historic
character of a preservation zone. Public spaces include streetscapes,
alleyscapes, and parks. Public buildings cover a broad variety of
buildings such as police stations, libraries, post offi ces, and civic
buildings.
Streetscapes add to the character of each HPOZ neighborhood through
the maintenance and preservation of historic elements. Street trees
in particular contribute to the experience of those driving or walking
through an HPOZ area. Character defi ning elements of streetscapes
may include historic street lights, signs, street furniture, curbs,
sidewalks, walkways in the public right-of-way, public planting strips
and street trees.
Alleys, the lowest category of streets, may not exist in all HPOZ areas,
but if present they traditionally serve as the vehicular entry and exit to
garages providing an important element of the neighborhood character.
Like alleys, parks are sometimes present in an HPOZ area and, as
such, traditional elements should be preserved and maintained, and
the addition of new elements should be compatible with the historic
character of the neighborhood.
Additions to public buildings may require the installation of ramps,
handrails and other entry elements that make a building entrance
more accessible. These elements should be introduced carefully so that
character-defi ning features are not obscured or harmed. Guidelines
relating to public buildings covering Americans with Disabilities Act
(ADA) requirements and location of parking lots are covered in this
section. Guidelines for new and existing historic public buildings are
the same as those in the commercial rehabilitation and infi ll sections
excluding those on storefronts. Please refer to those sections when
making changes, constructing additions or construction of new public
buildings.
Guidelines
Consult with the Public Works Department regarding new and
replacement work in the public right-of-way.
1. Protect and preserve street, sidewalk, alley and landscape
elements, such as topography, patterns, features, and materials
that contribute to the historic character of the preservation zone.
a. Preserve and maintain mature street trees.
b. Trim mature trees so that the existing canopies are preserved.
c. Preserve and maintain historically signifi cant landscaping in
the public planting strips.
Chapter 10 Public Realm: Streetscapes,
Alleyscapes, Parks, & Public Buildings
80
d. Use landscaping to screen public parking lots from view of
public streets.
e. New plantings in the public planting strip should be
compatible with the historic character of the Preservation Zone.
Paving and Curbs
2. Maintain and preserve historic curb confi guration, material and
paving.
3. For repair or construction work in the Preservation Zone right-of-
way, replace in-kind historic features such as granite curbs, etc.
4. Avoid confl icts between pedestrian and vehicular traffi c by
minimizing curb cuts that cross sidewalks.
Signage
5. Preserve and maintain historic street signs.
6. New street signage shall be placed so that historic features are
least obstructed.
Street Furniture
7. New street furniture, such as benches, bike racks, drinking
fountains, and trash containers, should be compatible in design,
color and material with the historic character of the Preservation
Zone. Use of traditional designs constructed of wood or cast iron is
encouraged.
Utilities
8. New utility poles, etc. shall be placed in the least obtrusive location.
Consider introducing new utility lines underground to reduce
impacts to historic character of preservation zone
Street Lights
9. Preserve and maintain existing historic street lights.
10. New street lighting should be consistent with existing historic
street lights. If there are no existing historic street lights, new
lights should be compatible in design, materials, and scale with the
historic character of the Preservation Zone.
Sidewalks
11. Preserve historic sidewalks.
12. Replace only those portions of sidewalks that have deteriorated.
When portions of a sidewalk are replaced special attention should be
paid to replicating score lines, texture, coloration and swirl-patterns.
81
Preservation Plan
13. New sidewalks should be compatible with the historic character of
the streetscape.
14. Maintain public walkway connections between streets and between
buildings.
Alley scapes
15. Preserve existing alleys as public rights-of-way.
16. Preserve traditional relationships between alleys and garages.
17. Preserve traditional fencing along alley right-of-ways.
18. The introduction of new fencing should be compatible with existing
historic fencing.
Public Buildings
19. New public buildings should comply with the appropriate In-fi ll
Design Guidelines.
20. Introduce accessible ramps and entry features so that character
defi ning elements of the building’s entryways are impacted to the
least extent possible.
21. Construct new access ramps and entry features so that they are
reversible.
22. Locate new parking lots and parking structures to the rear of public
buildings to reduce impacts on neighborhood character.
23. Construction of parking areas for public buildings should be
screened from view of adjacent residential structures.
Parks
24. Preserve and maintain any existing historic elements such as
walkway materials, mature trees, plantings, park benches and
lighting.
25. Replace in-kind elements that cannot be repaired.
26. New elements such as public benches, walkways, drinking
fountains, and fencing should be compatible with the existing
historic character of the Preservation Zone.
82
83
Preservation Plan
Arch: A curved structure for spanning an opening.
Architectural façade: The façade distinguished by the primary architectural features or detail.
Asymmetrical: Having no balance or symmetry.
Awnings: A canopy made of canvas to shelter people or things from rain or sun.
Balcony: An elevated platform projecting from the wall of a building, usually enclosed by a parapet or railing.
Baluster: Any of a number of closely spaced supports for a railing.
Balustrade: A railing with supporting balusters.
Barge Boards (verge boards): A board, often carved, attached to the projecting end of a gable roof.
Battered: Sloping, as of the outer face of a wall, that recedes from bottom to top.
Bay: A part of a building marked off by vertical or transverse details.
Bay window: A window or series of windows projecting outward from the main wall of a building and forming
a bay or alcove in a room within.
Belfry: A bell tower.
Blockface: The architectural setting formed by the conjunction of all the buildings in a block.
Board and Batten: Siding application where the vertical joints are covered with narrow strips of wood.
Boxed Cornice: A slightly projecting, hollow cornice of boards and moldings, nailed to rafters.
Bracket: A support projecting horizontally diagonally from a wall to bear the weight of a cantilever or for
decorative purposes.
Box (built-in) gutter: A gutter built into the slope of the roof, above the cornice.
Cantilevered: Horizontal element of a structure supported by horizontal, not vertical, structural members.
Canopy: Projecting element, usually over a façade opening, as if to provide shelter.
Casement: A window sash opening on hinges generally attached to the upright side of the windows frame.
Clapboard: A long, thin board with one edge thicker than the other, laid horizontally as bevel siding.
Clerestory window: Ribbon windows on the portion of an interior rising above adjacent rooftops.
Clinker brick: A very hard burned brick whose shape is distorted, knobby or bloated.
Column: A rigid, relatively slender vertical structural member, freestanding or engaged.
Coping: The top layer or course of a masonry wall, usually having a slanting upper surface to shed water.
Corbels: A stepped projection from a wall, usually masonry.
Cornice: A continuous, molded projection that crowns a wall.
Chapter 11: Defi nitions
84
Crown: The highest portion of an arch, including the keystone.
Cupola: A domelike structure surmounting a roof or dome, often used as a lookout or to admit light and air.
Dentil: Simple, projecting, tooth-like molding.
Dormer: A projecting structure built out from a sloping roof, usually housing a vertical window or ventilating
louver.
Double-hung window: A window with two sashes, both of which are operable, usually arranged one above
the other.
Eave: The overhanging lower edge of a roof.
Entablature: The upper of a building, resting on the columns and constituting the architrave, frieze, and
cornice.
Façade: The front or any side of a building.
Fascia: Any broad, fl at horizontal surface, as the outer edge of a cornice or roof.
Fenestration: The design, proportioning, and location of windows and other exterior openings of a building.
Finial: A sculptured ornament, often in the shape of a leaf or fl ower, at the top of a gable, pinnacle, or similar
structure
Frieze: A decorative horizontal band, as along the upper part of a wall.
Glazed: Filled with a pane of glass.
Gothic Arch: A pointed arch reminiscent of those found on Gothic Cathedrals
Grilles: A decorative screen, usually of wood, tile, or iron, covering or protecting an opening.
Half-timbering: Detail creating the appearance of exposed structural timbers on plaster.
Keystone: The wedge shaped detail at the top of an arch.
Louver: Fixed or movable horizontal slats for admitting air and light.
Marquee: A tall projection above a theatre entrance, often containing a sign.
Massing: The unifi ed composition of a structure’s volume, affecting the perception of density and bulk.
Molding: A slender strip of ornamental material with a uniform cross and a decorative profi le.
Newel post: A post supporting one end of a handrail at the top or bottom of a fl ight of stairs.
Ogee arch: An arch formed by two S-shaped curves meeting at a point.
Oriel: A bay window supported from below by corbels or brackets.
Parapet: A low protective wall at the edge of a terrace, balcony, orabove the roof line.
Patterned Shingles: Shingles, usually used as a sheathing material, which are cut and arranged so as to
form decorative patterns such as fi shscales, diamonds, scallops, etc.
85
Preservation Plan
Pediment: A wide, low-pitched gable surmounting a colonnade, portico, or major bay on a façade.
Pergola: An arbor or a passageway of columns supporting a roof of trelliswork on which climbing plants are
trained to grow
Pier: Vertical structural members.
Pilaster: A shallow rectangular projecting feature, architecturally treated as a column.
Pinnacle: A small turret or spire on a roof or buttress.
Porch: An exterior covered approach or vestibule to a doorway.
Porte cochere: A roofed structure covering a driveway to provide shelter while entering or leaving a vehicle.
Portico: A vertically proportioned porch having a roof supported by columns.
Quoin: An exterior angle of a masonry wall marked by stones or bricks differentiated in size and/or material
from adjoining surfaces.
Rafter: Any of a series of small, parallel beams for supporting the sheathing and covering of a pitched roof.
Rafter tail: Portion of a rafter which projects under the eave.
Scale: Proportionate size judged in relation to an external point of reference.
Showcase windows: Large glazed openings designed to showcase merchandise.
Sidelights: Vertical windows along the outside of a door.
Sleeping porch:
Soffi t: The underside of an architectural element, such as a beam or cornice.
Spandrel: The roughly triangular space between the left or right exterior curve of an arch and the rectangular
framework surrounding it.
Spindles: Slender architectural ornaments made of wood turned on a lathe in simple or elaborate patterns.
Spire: Structure or formation, such as a steeple, that tapers to a point at the top.
Splay: An oblique angle or bevel given to the sides of an opening in a wall.
Stair tower: A tower articulating the location of the stairway, usually of a residence.
Stoop: A raised platform, approached by steps and sometimes having a roof, at the entrance to a house.
Streetscape: The pattern and impression created by the combination of visible elements from all lots on a
blockface.
String courses: A horizontal course of brick or stone fl ush with or projecting beyond the face of a building,
often molded to mark a division in the wall.
Surround: The trim, jamb, head, and other decorative elements surrounding an opening.
86
Symmetry: Correspondence of form on opposite sides of a dividing line or plane.
Terra-Cotta: Usually red fi red clay.
Terrace: An open level area or group of areas adjoining a house or lawn.
Terrazzo: A poured fl ooring material, usually comprised of small pieces of stone or glass in a binding medium.
Tower: A structure high in proportion to its lateral dimensions, usually forming part of a larger building.
Transom: A window, usually operable, above the head of a door.
Trusses: A rigid framework, as of wooden beams or metal bars, designed to support a structure, such as a roof.
Turret: A structure (frequently curved) high in proportion to its lateral dimensions, forming part of a larger
building.
Tuscan columns: Very simple columns with no fl uting or other embellishment.
Veranda: A large, open porch, usually roofed, extending across the front and sides of a house.
Window Sash: One unit of an operable window, including the frame and glazing.
Wood shingle siding: A sheathing material composed of overlapping wood shingles.

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Asset Metadata

Creator Cai, Rongzhen (author)

Core Title Greening historic districts with solar roofs: an exploration of Western Heights in Los Angeles

School School of Architecture

Degree Master of Heritage Conservation

Degree Program Heritage Conservation

Publication Date 08/05/2019

Defense Date 08/05/2019

Publisher University of Southern California (original), University of Southern California. Libraries (digital)

Tag Heritage Conservation,Historic Preservation,Los Angeles historic districts,OAI-PMH Harvest,solar roofs,solar tiles,sustainable conservation

Format application/pdf (imt)

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Sandmeier, Trudi G. (committee chair), Hall, Peyton (committee member), Lesak, John (committee member)

Creator Email raine.rongzhencai@gmail.com,rongzhec@usc.edu

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c89-207266

Unique identifier UC11662240

Identifier etd-CaiRongzhe-7743.pdf (filename),usctheses-c89-207266 (legacy record id)

Legacy Identifier etd-CaiRongzhe-7743.pdf

Dmrecord 207266

Document Type Thesis

Format application/pdf (imt)

Rights Cai, Rongzhen

Type texts

Source University of Southern California (contributing entity), University of Southern California Dissertations and Theses (collection)

Access Conditions The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the a...

Repository Name University of Southern California Digital Library

Repository Location USC Digital Library, University of Southern California, University Park Campus MC 2810, 3434 South Grand Avenue, 2nd Floor, Los Angeles, California 90089-2810, USA