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Building retrofitting evaluation: Energy savings and cost effectiveness of building retrofits on Graduate Art Studios at the University of California, Los Angeles

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Building retrofitting evaluation: Energy savings and cost effectiveness of building retrofits on Graduate Art Studios at the University of California, Los Angeles

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Content 1

BUILDING RETROFITTING EVALUATION

Energy savings and cost effectiveness of building retrofits on Graduate
Art Studios at the University of California, Los Angeles

By

Tian Chen

Thesis Chair: Kyle Konis
Committee Members: Marc Schiler, Henry Koffman

A Thesis Presented to the
FACULTY OF THE SCHOOL OF ARCHITECTURE
UNIVERSITY OF SOUTHERN CALIFORNIA

In Partial Fulfillment of the
Requirements for the Degree
MASTER OF BUILDING SCIENCE

August 2018

Copyright 2018 Tian Chen
2

ABSTRACT

Buildings consume 39% of 𝐶𝑂
2
emissions and 70% of the electricity in the United States
(USGBC,2017). To improve the energy efficiency of buildings, the government has established
building energy codes and guidelines, such as Title 24 in the California Building Code. However,
more than 75% of the existing residential and commercial buildings in California were constructed
before the California Building Codes were established (California Air Resources Board, 2013). In
addition, the degradation of the building equipment and systems could have significant impact on
the building energy efficiency and the total energy usage. Thus, building retrofits will play an
important role in improving the energy efficiency of building and energy savings. In terms of
existing buildings, building retrofits can be categorized as case-by-case based upon the types of
the buildings and requirements of the building owner. During the decision-making process of
selecting the optimum building retrofits, it is difficult for building consultants, architects and
engineers to efficiently evaluate the cost-effectiveness and energy savings due to retrofitting. In
this thesis, energy modelling techniques (IES VE) and life-cycle cost analysis are implemented to
provide evaluations and recommendations for the UCLA Graduate Art Studio retrofits in
California. Different building retrofit options are proposed and evaluated to indicate the trade-off
between energy savings and economic benefits. The results show that the building retrofitting
could produce a 23% reduction in energy use intensity (EUI). However, retrofit options with the
higher energy savings also have the higher life-cycle cost due to high maintenance, equipment cost
and labor fees. The result of the thesis is expected to support the institutional building owners to
apply efficient building retrofit strategies.

Keywords: building retrofit, energy savings, IES VE, lifecycle cost, cost effectiveness
3

ACKNOWLEDGEMENTS

It would not be possible to complete this thesis without the help of the people around me. I would
like to express my gratitude to all of them.

My deepest gratitude goes to my family – my dad, mom, brother and uncle who always support
me for my studies and development. Their love and trust empower my growth during my journey
in the states.

I would like to express my sincere gratitude to my thesis chair, Professor Kyle Konis, who has
been consistently giving me suggestions on the thesis ideas and research directions. I would also
like to express my appreciation to my committee members, Professor Marc Schiler and Professor
Henry Koffman. They gave me a lot of insightful suggestions and comments throughout the
research. I would like to extend my thanks to Prof Karen Kensek for her advice and guidance on
thesis writing as well as efficient communication with my thesis committee team.

I would like to thank my MBS classmates, who offered a lot help and encouragement over the past
two years.

In addition, I would like to acknowledge the following individuals who have inspired my study,
research and practice in the architectural and engineering industry, Douglas Noble, Yiyu
Chen(Syska Hennessey Group), Dongwoo Yeom (Lawrence Technological University), Lynn
Shen, George Lui (ME Engineers) and Chuck Whitaker (John Labib + Associates).

4

CONTENTS
ABSTRACT ....................................................................................................................................2
ACKNOWLEDGEMENTS .............................................................................................................3
LIST OF TABLES ...........................................................................................................................9
LIST OF FIGURES ......................................................................................................................12
1. Introduction ..............................................................................................................................15
1.1 Why the Graduate School of Art at UCLA? .........................................................................15
1.2 The 2030 Challenge ................................................................................................................16
1.3 UC Carbon Neutrality Initiative .............................................................................................17
1.4 California building energy code .............................................................................................17
1.5 Building retrofit background ..................................................................................................18
1.5.1 Building retrofit process .................................................................................................18
1.5.2 Energy auditing ...............................................................................................................19
1.5.3 Building performance assessment ..................................................................................19
1.5.4 Energy prediction and qualification software .................................................................20
1.5.5 Economic analysis ..........................................................................................................20
1.5.6 Risk assessment and key factors affecting building retrofit ...........................................20
1.5.7 Conclusions .....................................................................................................................22
1.5.8 Research problem............................................................................................................23
1.5.9 Purpose of this research ................................................................................................. 23
1.5.10 Hypothesis.......................................................................................................................23
1.5.11 Research objectives .........................................................................................................23
2. Literature review ......................................................................................................................24
2.1 Energy Analysis .....................................................................................................................24
2.1.1 Existing building energy performance assessment .........................................................24
2.1.2 Energy quantification methods .......................................................................................24
2.1.2.1 Calculation-based method .............................................................................................24
2.1.2.2 Measurement-based method ..........................................................................................25
2.1.2.3 Hybrid method ...............................................................................................................26
5

2.1.2.4 Conclusions ...................................................................................................................26
2.1.3 Energy quantification tools .............................................................................................27
2.2 Case studies on ECMs selection of institutional buildings in California ...............................28
2.2.1 HVAC retrofit .................................................................................................................28
2.2.2 Lighting retrofit ...............................................................................................................29
2.2.3 A summary of retrofit examples .....................................................................................29
2.2.4 Conclusions .....................................................................................................................31
2.3 Economic analysis ..................................................................................................................32
2.3.1 Introduction .....................................................................................................................32
2.3.2 Discounted cashflow method ..........................................................................................32
2.3.3 Lifecycle cost analysis (LCCA) .....................................................................................32
2.3.3.1 Lifecycle cost (LCC) pattern .........................................................................................32
2.3.3.2 LCCA decision matrix ...................................................................................................33
2.3.3.3 Steps for LCCA process ................................................................................................34
2.3.3.4 Components of LCC ......................................................................................................34
2.3.3.5 Fundamental concepts related to life cycle cost ............................................................35
2.3.3.6 Energy cost ....................................................................................................................36
2.3.4 Relevant research ............................................................................................................38
2.3.4.1 Relevant research 1 .......................................................................................................38
2.3.4.2 Relevant research 2 .......................................................................................................39
2.3.5 Conclusions .....................................................................................................................40
3. Method of energy savings and economic analysis ...................................................................41
3.1 Introduction ............................................................................................................................41
3.1.1 Problem of current methodologies and proposed methodology .....................................41
3.1.2 Overall workflow development .....................................................................................41
3.2 Existing building information collection and analysis ...........................................................42
3.2.1 Introduction .....................................................................................................................42
3.2.2 Existing building information collection ........................................................................42
3.2.2.1 Location and weather information ................................................................................42
3.2.2.2 Existing architectural buildings .....................................................................................44
6

3.2.2.3 Existing building materials ............................................................................................46
3.2.2.4 Existing MEP drawings .................................................................................................47
3.2.2.5 Building energy consumption and utility data ..............................................................48
3.2.2.6 Indoor thermal comfort .................................................................................................52
3.2.2.7 Existing building condition summary ...........................................................................53
3.3 Propose specific ECMs ..........................................................................................................53
3.3.1 Baseline model descriptions ...........................................................................................53
3.3.2 Detail of retrofit case 1 ...................................................................................................60
3.4 IES VE model set up and process ..........................................................................................62
3.4.1 Introduction .....................................................................................................................62
3.4.2 ModelIT ..........................................................................................................................63
3.4.3 Apachsim ........................................................................................................................65
3.4.4 ApacheHVAC .................................................................................................................67
3.4.5 Energy ranking model .....................................................................................................71
3.5 Lifecycle cost analysis, energy savings cost and LCC savings ..............................................72
3.5.1 LCCA boundary ..............................................................................................................72
3.5.2 LCCA economic factors .................................................................................................72
3.5.3 ECM investment cost ......................................................................................................72
3.5.4 Repair and maintenance cost ..........................................................................................72
3.5.5 Operational cost ..............................................................................................................75
3.5.6 Cost effectiveness model ................................................................................................78
4. Data collection and results .......................................................................................................79
4.1 Research problem ...................................................................................................................79
4.2 Single retrofit case energy savings and lifecycle cost analysis ..............................................79
4.2.1 Introduction .....................................................................................................................79
4.2.2 Building envelope - glazing options ...............................................................................80
4.2.3 Building envelope - roof options ....................................................................................82
4.2.4 Building envelope - exterior wall options .......................................................................86
4.2.5 Building HVAC system options .....................................................................................91
4.2.6 Lighting system retrofit options ....................................................................................102
7

4.3 Energy savings of each individual retrofit option ................................................................102
4.3.1 Skylight retrofit - different glazing types .....................................................................105
4.3.2 Roof retrofit -improved insulation ................................................................................106
4.3.3 Existing exterior wall retrofit - improved insulation ....................................................107
4.3.4 New construction exterior wall retrofit - improved insulation .....................................107
4.3.5 HVAC system retrofit - different HVAC system .........................................................108
4.3.6 Lighting retrofit option ................................................................................................109
4.4 Lifecycle cost .......................................................................................................................109
4.4.1 Lifecycle cost comparison of different retrofit options in 15 years lifetime ................109
4.4.2 Lifecycle cost comparisons of different retrofit options in 30 years lifetime ...............113
4.4.3 Energy usage comparisons: baseline model VS retrofit case 1 ....................................116
4.4.4 Lifecycle cost comparisons of baseline model and retrofit case 1 ................................117
4.4.5 Investment cost comparisons of baseline model and retrofit case 1 .............................119
4.5 Conclusions ..........................................................................................................................121
5. Discussion ..............................................................................................................................122
5.1 Introduction ..........................................................................................................................122
5.2 Investment cost and energy cost savings ..............................................................................122
5.3 Cost effectiveness analysis ...................................................................................................123
5.4 EUI improvement (%) vs annual energy cost reduction ......................................................126
5.5 EUI improvement (%) vs investment cost increment (%) ...................................................126
5.6 EUI improvement (%) vs lifecycle cost increment (%) .......................................................127
5.7 Rebates and incentives .........................................................................................................129
5.8 HVAC outdoor unit downsizing/upsizing ............................................................................130
5.9 Discussion of the results .......................................................................................................131
5.9.1 Why the hypothesis is disproved? ................................................................................132
5.9.1.1 High investment cost ...................................................................................................132
5.9.1.2 Evaluation of the baseline model ................................................................................132
5.9.1.3 Limitations of existing retrofit options and recommendations ...................................133
5.10 Research findings .............................................................................................................133
5.10.1 Consider HVAC equipment downsizing/upsizing for building envelope retrofit ........133
8

5.10.2 The impact of rebates and incentives on lighting retrofits ............................................133
6. Future work ............................................................................................................................134
6.1 Future work and conclusions ................................................................................................134
6.2 Explore more factors related to building energy ..................................................................134
6.3 Test and evaluate the assumptions of cost information and economic factors ....................135
6.4 Rebates and incentives .........................................................................................................135
Bibliography ................................................................................................................................136

9

LIST OF TABLES
Table 1.1: Building envelope U factor requirements in Title 24, 2016 .........................................18
Table 1.2: Common energy conservation measures ......................................................................21
Table 2.1: Summary of school building retrofit in California .......................................................30
Table 2.2: Trends in average rates of electric utility costs ............................................................37
Table 2.3: System average rates of costs of electric utilities from 2012 to 2016 ..........................37
Table 2.4: Average prices for gasoline, electricity and utility (piped) gas, Los Angeles ..............37
Table 2.5: Cost summary for three retrofit approaches .................................................................39
Table 3.1: Existing building materials ...........................................................................................46
Table 3.2: Existing HVAC system.................................................................................................47
Table 3.3: Baseline building information ......................................................................................55
Table 3.4: Internal heat gains and occupancy level .......................................................................57
Table 3.5: Rooms under the same thermal zones ..........................................................................59
Table 3.6: Retrofit options for baseline model ..............................................................................59
Table 3.7: Retrofit cases comparisons ...........................................................................................60
Table 3.8: Details of retrofit case 1 ................................................................................................60
Table 3.9: LCCA economic factors ...............................................................................................72
Table 3.10: SPV factors for future single costs .............................................................................73
Table 3.11: Life expectancy of HVAC components ......................................................................74
Table 3.12: UPV factors for annually recurring uniform costs .....................................................75
Table 3.13: UPV factors for fuel price escalation..........................................................................76
Table 4.1: Descriptions and details of glazing options ..................................................................81
Table 4.2: Thermal properties of glazing retrofit options ..............................................................82
Table 4.3: Cost information of glazing retrofit options .................................................................82
Table 4.4: The Baseline roof and its roofing thermal properties ...................................................83
Table 4.5: Thermal properties of roof options ...............................................................................83
Table 4.6: Cost Information of roofing system ..............................................................................84
Table 4.7: Cost information of existing roof structure ..................................................................85
10

Table 4.8: Summary of roof cost ...................................................................................................86
Table 4.9: Existing wall retrofit options ........................................................................................87
Table 4.10: Thermal properties of existing wall assemblies (retrofit case 1) ...............................88
Table 4.11: Existing wall retrofit options ......................................................................................88
Table 4.12: Cost Information of existing wall retrofit options ......................................................88
Table 4.13: Cost information of insulation layers .........................................................................89
Table 4.14: Thermal properties of wall assemblies in retrofit case 1 ............................................90
Table 4.15: Thermal properties and cost information of new wall assemblies in retrofit case 1 ..90
Table 4.16: HVAC system comparisons ........................................................................................91
Table 4.17: Packaged air conditioner price ....................................................................................92
Table 4.18: VRF condensing unit cost 1 ........................................................................................93
Table 4.19: VRF condensing unit cost 2 ........................................................................................94
Table 4.20: VRF indoor unit cost (fan coil unit) ...........................................................................94
Table 4.21: CAV system and VAV system cost comparisons (summarized from cost reports) ..96
Table 4.22: VRF system cost information (collected from cost reports) ......................................97
Table 4.23: Area for different HVAC retrofit options ...................................................................98
Table 4.24: Investment cost comparison of HVAC retrofit options ..............................................98
Table 4.25: Life expectancy of HVAC equipment ......................................................................100
Table 4.26: Annual maintenance cost comparison of HVAC retrofit options .............................100
Table 4.27: 15 Years maintenance and replacement cost comparisons of HVAC options .........101
Table 4.28: 30 Years maintenance and replacement cost comparisons of HVAC options .........101
Table 4.29: Lighting retrofit options ............................................................................................102
Table 4.30: Annual maintenance cost comparisons of lighting retrofit options ..........................102
Table 4.31: Summary of EUI improvement on single retrofit options ........................................103
Table 4.32: Energy savings rankings ...........................................................................................105
Table 4.33: Lifecycle cost of single retrofit options in 15 years lifetime ...................................110
Table 4.34: 15 years lifecycle cost rankings ................................................................................112
Table 4.35: 30 years lifecycle cost comparisons of different retrofit options .............................113
11

Table 4.36: 30 years lifecycle cost rankings ................................................................................115
Table 4.37: Baseline model and retrofit options energy consumption comparisons ...................116
Table 4.38: Lifecycle cost comparisons between the baseline model and retrofit case 1 ...........117
Table 4.39: Investment cost comparisons between the baseline model and retrofit case 1 .........119
Table 5.1:15 years and 30 years cost effectiveness comparisons ................................................123
Table 5.2: 15 years lifecycle cost increment (%) vs 30 years lifecycle cost increment (%) .......127
Table 5.3: The impact of lighting rebates on 15 years & 30 years lifecycle cost increment (%) 130

12

LIST OF FIGURES
Figure 1.1: UCLA graduate art studios .........................................................................................15
Figure 1.2: The 2030 Challenge ....................................................................................................16
Figure 1.3: Key steps for sustainable building retrofit .................................................................19
Figure 2.1: Energy quantification method .....................................................................................24
Figure 2.2: Lifecycle cost pattern ..................................................................................................33
Figure 2.3: LCCA decision matrix.................................................................................................33
Figure 2.4: Methodology diagram .................................................................................................40
Figure 3.1: Current methodology ...................................................................................................41
Figure 3.2: Proposed methodology ................................................................................................41
Figure 3.3: Overall workflow development ...................................................................................42
Figure 3.4: Weather information of climate zone 8 .......................................................................43
Figure 3.5: Psychrometric chart for climate zone 8 .......................................................................43
Figure 3.6: Existing floor plan .......................................................................................................44
Figure 3.7: Existing floor plan .......................................................................................................45
Figure 3.8: New floor plan .............................................................................................................46
Figure 3.9: Photos of existing building envelope ..........................................................................47
Figure 3.10: Existing lighting fixture layout..................................................................................48
Figure 3.11: Monthly electricity consumption in 2015 and 2016 ..................................................49
Figure 3.12: Monthly electricity bills in 2015 and 2016 ...............................................................49
Figure 3.13: Monthly natural gas consumption (therms) in 2015 and 2016 .................................50
Figure 3.14: Monthly natural gas bills in 2015 and 2016 ..............................................................50
Figure 3.15: Monthly water consumption in 2015 and 2016 .........................................................51
Figure 3.16: Monthly water bills in 2015 and 2016.......................................................................51
Figure 3.17: Air temperature in five locations ...............................................................................52
Figure 3.18: Air humidity in five locations ...................................................................................52
Figure 3.19: Thermal zones at the first floor .................................................................................58
Figure 3.20: Thermal zones at the second floor .............................................................................58
13

Figure 3.21: IES VE procedures ....................................................................................................62
Figure 3.22: 2D and 3D model in IES VE .....................................................................................63
Figure 3.23: Project construction interface 1 in IES VE ...............................................................64
Figure 3.24: Project construction interface 2 in IES VE ...............................................................64
Figure 3.25: Internal heat gain for each room in IES VE ..............................................................65
Figure 3.26: Building template manager in IES VE ......................................................................65
Figure 3.27: Occupancy weekly profile in IES VE .......................................................................66
Figure 3.28: Details of the occupancy occurrence on weekday .....................................................66
Figure 3.29: Method diagram of HVAC system set up in IES VE ................................................67
Figure 3.30: ApacheHVAC interface in IES VE ...........................................................................67
Figure 3.31: Rooms under the same type of HVAC system in IES VE ........................................68
Figure 3.32: Details of packaged air conditioner (PAC) in IES VE ..............................................68
Figure 3.33: Setpoints of HVAC system in IES VE ......................................................................69
Figure 3.34: Outdoor air ventilation of HVAC system in IES VE ................................................69
Figure 3.35: System parameters output in IES VE 1 .....................................................................69
Figure 3.36: System parameters output in IES VE 2 .....................................................................70
Figure 3.37: Monthly energy usage from each end use in IES VE ................................................70
Figure 3.38: Yearly end use pie chart in IES VE ...........................................................................70
Figure 3.39: Natural gas prediction by EIA (2015) ......................................................................77
Figure 3.40: Electricity prediction by EIA (2015) ........................................................................77
Figure 4.1: Roof section view of retrofit case 1 .............................................................................83
Figure 4.2: Existing wall 1a (baseline) and existing wall 1b (retrofit case 1) ..............................87
Figure 4.3: Baseline wall assemblies (New construction) ............................................................90
Figure 4.4: Retrofit Case 1 Wall assemblies (New construction) .................................................90
Figure 4.5: HVAC system cost estimation diagram ......................................................................92
Figure 4.6: Packaged air conditioner investment cost model .......................................................93
Figure 4.7: VRF outdoor condensing unit cost model ...................................................................94
Figure 4.8: VRF indoor fan coil unit cost model ...........................................................................95
14

Figure 4.9: Investment cost comparisons of HVAC retrofit options .............................................99
Figure 4.10: EUI (kBtu/ft2) of different retrofit options .............................................................104
Figure 4.11: Energy saving rankings ...........................................................................................104
Figure 4.12: EUI and energy savings (%) of different skylight options ......................................106
Figure 4.13: EUI and energy savings (%) of different roof options ............................................106
Figure 4.14: EUI and energy savings (%) of different existing exterior wall options .................107
Figure 4.15: EUI and energy savings (%) of different exterior wall options (N) .......................108
Figure 4.16: EUI and energy savings (%) of different HVAC systems ......................................108
Figure 4.17: EUI and energy savings (%) of different lighting options ......................................109
Figure 4.18: 15 years Lifecycle cost comparisons of all single retrofit options ..........................111
Figure 4.19: 15 years lifecycle cost and lifecycle cost increment (%) ........................................112
Figure 4.20: 30 years lifecycle cost comparisons of all single retrofit options ...........................114
Figure 4.21: 30 years lifecycle cost and lifecycle cost increment (%) .......................................116
Figure 4.22: 15 years lifecycle cost comparisons (Baseline model & retrofit case 1) .................118
Figure 4.23: 20 years lifecycle cost comparisons (Baseline model & retrofit case 1) .................118
Figure 4.24: Investment cost distribution of the baseline model .................................................119
Figure 4.25: Investment cost distribution of retrofit case 1 .........................................................120
Figure 4.26: Investment cost comparisons between the baseline model and retrofit case 1 .......120
Figure 5.1: Investment cost increment ($/ft2) VS energy cost savings .......................................122
Figure 5.2: 15 years cost effectiveness rankings of retrofit options ............................................124
Figure 5.3: 30 years cost effectiveness rankings of retrofit options ............................................125
Figure 5.4: 15 years and 30 years cost effectiveness rankings comparisons of retrofit options ..125
Figure 5.5: Correlations between EUI improvement (%) and annual energy cost reduction (%)
......................................................................................................................................................126
Figure 5.6: Correlations between EUI improvement (%) and investment cost increment (%) ...127
Figure 5.7: 15 years lifecycle cost change (%) vs 30 years lifecycle cost (%) ............................128
Figure 5.8 The impact of lighting rebates on 15 & 30 years lifecycle cost increment (%) .........139
Figure 5.9: 15 years energy cost savings and HVAC equipment cost change due to equipment
upsizing or downsizing ................................................................................................................131
15

1. Introduction
1.1 Why the graduate art studios at UCLA?
The University of California at Los Angeles (UCLA) Graduate School of Art is a two-story
concrete building. It is located in a former industrial zone of Culver city, west of Los Angeles and
near the Los Angeles International Airport. It consists of 40 studios, one office, and additional
miscellaneous rooms such as a central bay, a sculpture lab, a woodshop, a ceramics room, etc.
Most of the rooms are located on the first floor, while a few other offices and labs are located on
the second floor. The new campus will include the renovation of a 20,774 square-foot former
wallpaper warehouse and an 18,500-square foot expansion.

Figure 1.1: UCLA graduate art studios
This university building was selected to be the case study for this research based upon three criteria.
The first criterion is that the University of California has been a pioneer in the sector of energy
and building sustainability. Conducting a building retrofit study on this building could assist
university building owners and investors in choosing better investment for energy retrofits. The
second criterion is the necessity of a building retrofit as selecting an ongoing building retrofit
project is the intent of this research. The UCLA Graduate Art Studios, also named as “Warner
Studios”, was first built as a warehouse in 1948. After several makeshift additions, it was used as
an art studio by UCLA graduate art students starting in 1985. The studio is located in an area of
the buildings which is fully dark and without electrical lighting. Moreover, its indoor environment
is poorly ventilated due to the malfunction of its existing building systems and the inefficiency of
its building envelope design. The renovation plan of this building was first proposed five years
ago but was halted due to a lack of funding. The retrofit plan was resumed this year with the
support of donations and its completion is targeted for 2019. The third criterion is the accessibility
of the building information. Compared with privately owned buildings, the building data of public
university building are easily accessible and obtained.
16

Applicable codes:
• 2016 California Building Code (CBC), Title 24 Part 6.
• 2016 California Energy Code (CEC), Title 24 Part 6.
• 2016 California Green Building Standards Code (CAL Green), Title 24, Part 11.
1.2 The 2030 Challenge

Figure 1.2: The 2030 Challenge (Architecture 2030, 2010)
The six types of economic activities that contribute to the production of global greenhouse gas
emissions are electricity and heat production, agriculture, forestry and other land use,
transportation, industry, buildings, and other energy. Buildings account for 39% of 𝐶𝑂
2
emissions
in United States while globally buildings account for 6% of the greenhouse gas emissions
(Environmental Protection Agency, 2010). The 2030 Challenge was proposed by Architecture
2030 with several targets that were identified to complete the objective to slow down the carbon
emissions’ impact on climate change in the building sector.
• The fossil fuel, greenhouse gases emissions, energy performance of all the new buildings,
and the development and renovations of existing building must be designed to be 70%
below the average of buildings of the same types
• At a minimum, existing buildings with areas equal to the existing building should follow
the above rule.
• By 2020, the fossil fuel energy consumption needs to be reduced by 80% and by 2025, it
should be reduced by 90%.
• In 2030, carbon neutrality should be achieved and there should be no fossil fuel consumed.
17

Due to the scope of this project, the case study used for this thesis will not reach net zero
individually. However, it is involved in the UC Carbon Neutrality Initiative as illustrated below.
1.3 UC Carbon Neutrality Initiative.
The University of California (UC) carbon neutrality Initiative (CNI) was proposed by Janet
Napolitano, the President of the University of California to mitigate the University of California’s
contributions to the greenhouse emissions, in November 13, 2013. CNI commits UC to emit net
zero greenhouse gases from its buildings and the use of its vehicle fleet by 2025. The initiative
requires climate research, improved renewable energy, and building energy efficiency in order to
reduce carbon emissions. Several steps will be taken by UC to achieve carbon neutrality. For
example, an agreement of 80-megawatts solar power at the start of 2017 has been made by UC to
replace the major source of fossil fuels with renewable energy. UC will seek for the state’s
investment and other funding to create more energy efficiency projects. Furthermore, UC will seek
to replace the large-scale use of conventional natural gas by renewable natural gas (mostly bio-gas
generated from waste), which will produce 73% of the power for the entire UC campus (UC
Carbon and Climate Neutrality Summit, 2015).
1.4 California Building Energy Code:
In 1974, California was the first state in United States to include minimum energy standards in the
building regulations. The California Energy Commission (CEC) was then established to set the
energy efficiency standards. There are two types of energy codes, non-residential code and
residential code. Realizing that buildings account for 39% of the energy consumption and 72% of
the electricity load in the United States. the CEC put forth great efforts on accelerating significant
energy savings through the implementation of the California Building Energy Code, which helped
California use less energy per capita than any other state in the US. Then in 2008, the California
Governor challenged the CEC on achieving the Zero Net Energy for residential and non-residential
building by 2020 and 2030, respectively. The goals were then set forth in section 11 of Title
24/Section 6 in California’s 2016 Energy Code. The 2016 standards include three major areas,
which are mandatory requirements that need be applied in all buildings, as well as performance
standards that could vary based upon different climate zones, and an alternative to the performance
standards (a recipe or a checklist compliance approach). (CEC, 2013) The latest California
Building Energy Efficiency Standards are available at:
http://www.energy.ca.gov/2015publications/CEC-400-2015-037/CEC-400-2015-037-CMF.pdf
The main chapters of the Title 24 document address requirements for building envelope, HVAC
systems and water heating systems, indoor lighting, outdoor lighting, sign lighting, electrical
power distribution, solar ready requirements, etc. For example, under the prescriptive requirements,
the U factor of the exterior wall assemblies much be equal or lower than the requirement.

18

Table 1.1: Building envelope U factor requirements in Title 24, 2016 (CEC, 2016)

The Title 24 energy standards also provide prescriptive and performance approaches for additions
and alterations, but not for repair. For example, a minimum of R-13 insulation between framing
system or U factor no greater than 0.113 is required for wall insulation of metal framed walls under
alterations. Addition means increased conditioned floor area and volume based on existing
footprint while alteration is a change for the existing building, including change to HVAC system,
lighting and window systems. Repair is reconstructing or renewing the existing building parts for
maintenance. The performance method of compliance was used for this case study since it
compared performance of the designed building changes with prescriptive compliance.
The performance compliance needs to be assessed with a computer to conduct calculations to meet
the Title 24 code. CEBECC-com, IES Virtual Environment and EnergyPro are approved to be used
for Title 24 compliance.
1.5 Building retrofit background
1.5.1 Building retrofit process
The goal of building retrofits is to choose and implement the most cost-effective energy
conservation measures to enhance the energy performance as well as provide required building
services and acceptable indoor thermal comfort. The process of building retrofit at different phases
are summarized below. (Zhenjun Ma, 2012)
The first phase is a pre-retrofit survey and project set up. The scope of work and project targets
need to be addressed at this stage. The pre-retrofit survey could help understand the building
operational problems as well as the occupant’s concerns. The second process consists of an energy
audit, performance assessment and diagnostics. The building energy data and energy usage is
19

analyzed to identify the energy wastes. Then the low-cost energy conservation measures can be
identified after the analysis. In term of building performance assessment, performance indicator or
green building rating systems could be used to benchmark the building energy usage. Inefficient
equipment and building controls, malfunctions inside the building could be inspected. The third
process is identifying of retrofit options. Quantitative performance assessment could be conducted
for different retrofit alternatives and the retrofit alternatives then can be categorized considering
energy-related and non-energy related factors. The selection of retrofit options might also be
determined in the process of the energy audit. (Zhenjun Ma, 2012)

Figure 1.3: Key steps for sustainable building retrofit (Zhenjun Ma, 2012)
The phase four includes site implementation, test and commissioning (T&C). This phase is to make
sure the building and its service systems conduct optimal operation. But it should be noted that the
implementation of certain retrofit measures might have significant interruptions to the building
and occupant. The last phase is validation and verification, including post occupancy survey, post
measurement and verification. This phase is designed to collect the satisfaction level of occupants
on the retrofit results. At the same time, M(Measurement) &V (Verification) is used for the
verification of energy savings. The purpose of the M&V process is comparing the difference of
energy usage before retrofits and after retrofits (Efficiency Valuation Organization,2012).
Considering the timeline of the thesis, phase four and phase five will not be involved since the
retrofitting for the studied building will start in 2019.
1.5.2 Energy auditing
Energy audits means investigation and surveys of energy usage and energy efficiency in the
building or buildings, which requires identification of energy usage from energy cost or control
measures. It helps to identify the energy saving potentials and provide essential building
information for building performance assessment. The energy audits are usually divided into three
levels: the first level is a walk-through assessment; the second level is an energy survey and
analysis and the third level is a detailed energy analysis. The level of energy audits for a specific
project could be determined by the amount of detail and level of accuracy needed. The available
budget, project goals and scope of work will also affect the selection of energy audits. (Jim Kelsey,
2011)
20

1.5.3 Building performance assessment
During a building retrofit project, the building performance assessment is used for identifying the
building energy usage, system operational problems and to figure out the energy savings solutions.
There are different types of energy performance assessment tools. For example, LEED (US),
BREEAM (UK), HK-BEAM (HK) are commonly used for new and existing building performance
assessment, mainly for commercial sectors. It compares the energy/cost or CO2 emissions of
“assessed building” with that of self-referenced “baseline” building and the score is given based
on the percentage of energy/ CO2 reduction. The building energy could either be collected by
measurement of existing building or energy simulation. Energy Star (US), Cal-Arch (US), Energy
Smart Office Label (Singapore) are tools mainly used for whole building benchmarking.
(ShengWei Wang, 2012)
1.5.4 Energy prediction and quantification software
There are many tools available in the market to assist building owners to predict and evaluate the
energy performance. This also provides comparisons of the energy efficiency benefits brought by
different energy conservation measures.
The reliable energy benefits predication and quantification is very crucial to assist selecting
optimum sustainable building retrofit plan. There are several building energy simulation packages
which could provide whole-building energy simulation and simulate the thermodynamic
conditions of the building such as EnergyPlus, DOE-2, IES VE, eQuest, TRANSYS, etc. The
energy prediction reliabilities are different among these energy simulation tools and each
simulation package is developed on certain assumptions. Also, the model selection and parameter
identifications plays an essential role on accurate energy estimation. Thus, it is important for users
to realize these potential uncertainties while using these energy simulation packages. (Zhenjun Ma,
2012)
1.5.5 Economic analysis
It is difficult to select the suitable techniques to evaluate the cost-effectiveness of the certain
conservations measures. The trade-off between the capital investment and economic benefits
brought by retrofit measures assists the comparisons between different retrofit measures and
indicates whether the retrofit alternatives are cost-efficient and energy-efficient. There are multiple
economic analysis methods for evaluation on feasibility of building retrofit measures, such as net
present value (NPV), internal rate of return (IRR), overall rate of return (ORR), benefit-cost ratio
(BCR) and payback period (DPP) and simple payback period (SPP). The lifecycle cost analysis
method and other advanced cost method could also be applied to evaluate the cost-effectiveness
of retrofit measures. (Frank Kreith, 2007)
1.5.6 Risk assessment and key factors affecting building retrofit
Risk assessment is the identification of quantitative and qualitative value of risk in certain
situations. It provides decision maker of building retrofits projects with the information of “risk
exposure” in certain situation, for example, it offers possibility of estimated result being different
from the “best-guess”. As mentioned earlier, the building retrofit project is influenced by
21

uncertainty factors, for example, uncertainty resulted from energy savings estimations, weather
data used, system performance degradations, etc. The investment decisions for building retrofit
could be highly affected by these uncertainties, thus it is important to take risk assessment into
consideration during the decision-making process. Among the risk management method, the most
commonly used method is possibility-based method and it includes expected value analysis, mean-
variance criterion, variation coefficient, risk-adjusted discount rate technique etc. (Frank Kreith,
2007)
There are several key factors which could have significant impact on the building retrofit,
including building information, policies and regulations, energy conservation measures, human
factor, client resources & expectations. (Zhenjun Ma, 2012)
• Building information
• The building information can have an impact on the effectiveness of building retrofits,such as
building types, building location, built year, occupancy schedule, operation and maintenance,
energy sources, building envelope, building systems. The optimum building retrofit options
should consider each element of building-specific information. Policies and regulations
• Government policies and regulations, such as energy efficiency standards. In California, for
example, Title 24 set up the minimum energy standards for the building retrofits.
• Energy conservation measures
The energy conservation measures, include energy efficient building service equipment, advanced
building controls, renewable energy systems, applications of advanced heating and cooling
technologies. These techniques are used to achieve sustainability and energy efficiency. The most
common energy conservation measures used for building retrofit in United States are listed below.
Simple payback period is used to describe the return potential of different energy conservation
measures. The payback means the time to cover the capital investment by the cost resulted from
energy usage reduction. There is another type of retrofit which is not included are building
envelope retrofit. The building envelope improvement such as efficient insulation and coating
materials, higher performance windows could provide significant benefits (Mark Fulton, 2012)
Table 1.2: Common energy conservation measures (Mark Fulton, 2012)

22

• Client resources & expectations
The project goals and targets are usually determined by client resources and expectations, as are
the retrofit technologies. It is difficult to determine if the retrofit options are worthwhile due to the
complexity of decisions on energy efficiency investment. The factors which have impact on energy
efficient investment were first investigated by Jane Harris (2000). Pay-back period was found to
be the mostly widely used decision making rule among the varies of different factors. It was
pointed out by Ali Alajmi (2011) that the retrofitting ECMs with significant capital investment can
save maximum annual energy consumption by 49.3% while the non-retrofitting ECMs which has
low capital investment could only save annual energy consumption by 6.5%.
• Other essential issues related to building retrofits
The retrofit options applied to one building might not be suitable for retrofitting other buildings.
Also, the benefits of multiple ECMs is not a sum of benefits from each ECMs. It depends on the
thermodynamic performance and physical interaction between different ECMs. (A.M. Rysanek,
2012)
1.5.7 Conclusions
Promoting the development of deep building retrofits is very important to reduce energy use,
pollution and greenhouse gas emissions in the existing buildings. Building retrofits could also
provide several benefits, such as improved indoor thermal comfort, improved energy efficiency
and increased tenant/worker productivity. However, the retrofitting of existing buildings has many
challenges and there are several uncertainties influencing the building retrofits, such as
government policy change and climate change. All these factors directly affect the selection of
retrofit technologies and the success of a retrofit project. Also, the different impact brought by
different building retrofit measures makes it complex to select the optimum building retrofits
measures. For any building retrofit project, it has become a technical challenge to deal with the
system interactions and uncertainties. (L. Tobias, 2009) There are also other challenges such as
financial barriers and limitations and long payback periods for retrofit strategies. Although there
are many building retrofit technologies available in the market, the decision-making process of
selecting certain retrofit measures for a particular project is a multi-objective optimization process,
which is affected by limitations and constraints, for example, budget, project target, building
services types and efficiency, building fabric, government policy and building type. It is a trade-
off between several energy-related factor and non-energy related factors, including energy,
regulations and economic factors. (Zhenjun Ma, 2012)

1.5.8 Research problem

The building retrofit project requires a multi-objective optimization process. It is difficult for
building designers and engineers to evaluate the energy efficiency and cost-effectiveness of certain
energy conservation measures and to select the optimum building retrofit plans.

1.5.9 Purpose of this research

23

• Generate a work flow/ methodology to assist engineers/designers to select the optimum
building retrofits plans in terms of energy efficiency and cost-effectiveness.
• Using IES VE and lifecycle cost analysis to assist building retrofit options selections.

1.5.10 Hypothesis
Deep-energy retrofits are cheaper than expected if a lifecycle cost approach is taken.
1.5.11 Research objectives
1. Compare first cost, to LCC (considering 2 and 3)
2. Quantify LCC including expected and possible future energy price change
3. Incorporating some on-site information in the assessment
4. Develop approach to isolate the cost of specific ECMs
5. Conduct energy simulations on different retrofit options

24

2. Literature review
2.1 Energy analysis
2.1.1 Existing building energy performance assessment
The type of building energy performance assessment adopted in this research is highly dependent
upon time and budget, although the detailed building information collection and measurement will
facilitate assessing the building energy performance. For existing building performance
assessment for diagnosis, both calculated and measured approaches are applicable. The
calculation-based approach requires detailed building data, such as characteristics of the building
envelope, HVAC system, and occupancy schedules in order to model the building. The measured
approaches are based on metered measurement and the measurement could be a representative
indicator of the actual energy usage of the building. Compared with the calculation-based method,
the measuring approach could reflect the real building performance and other related factors, such
as building design, building operation conditions, and thermal comfort.
2.1.2 Energy quantification methods
To conduct a quantitative analysis for the energy expenditure of the building, it is important to
select a suitable method. The energy quantification process requires the utilization of the available
information related to building’s energy in order to determine the building’s energy usage.
Monthly utility bills, end-use sub metering, and simulation are the common resources for
quantifying the building’s energy performance (Hashem Akbari, 1995). The energy quantification
methods are categorized into three distinct types, which are the calculation-based method, the
hybrid method, and the measurement-based method (Shengwei Wang, 2012).

Figure 2.1: Energy quantification method (Shengwei Wang, 2012).
2.1.2.1 Calculation-based method
Inputs, calculation model (influential factors), and outputs (energy performance indicators) are
three major components of the calculation method. The calculation method could be further
divided into two subcategories, which consist of the dynamic method and the steady-state method.
The dynamic method takes the thermal dynamics of envelope and system dynamics into
25

consideration while the steady-state method replaces the dynamic effects with correlation factors.
Such simplifications in the steady-state method would decrease the simulation accuracy to some
extent. DOE-2, EnergyPlus, TRNSYS and IES VE are the representative tools using dynamic
simulations. The steady-state method is used for simplified building energy calculations, and it
has the advantages of high computational speed and simplifications in modelling. There are two
opposing methods to build a steady-state method, which are forward modeling and inverse
modeling. SBEM (Simplified building energy model) is one such method using a forward
modeling approach while the whole-building regression method, BIN and modified BIN method,
and the equivalent full-load-hour method is based on inverse modeling techniques. (Shengwei
Wang, 2012).
2.1.2.2 Measurement-based method
There will be discrepancies between the actual and predicted building energy usages for any
calculations. The new building energy prediction could only rely on a calculation-based approach
while the existing building approach could also adopt a measurement-based calculation. The
measurement-based calculation consists of energy-bill based and monitoring-based methods.
An energy-bill based method is the most cost-effective method for quantifying most existing
building energy totals. To accurately understand the end usage of a building’s energy, it is
important to dissect and obtain a certain level of accuracy of the entire energy usage of the building
with regard to the end uses of its systems and equipment. The energy-bill based calculation could
be divided into three distict methods, which are the bottom-up calculation method, the bottom-
up short-term measurement method, and the end-use disaggregation method. (Shengwei
Wang, 2012).
The bottom-up calculation method consists of dividing the energy bill into the different types of
end uses (J.Field, 1997). The individual calculation of each item could be summed for
reconciliation with metered information. There are several types of information related to the end
use information such as the related electric load, electrical load factor, usage pattern, and usage
factor. To adjust the discrepancies between the results obtained from the calculation- based method
and metered information, it is often necessary to adjust the usage pattern to make the summed
energy usage match more closely to the measured consumption (Robert Cohen, 2010). The bottom-
up method could be very labor-intensive due to the extensive inspection of various of different end
uses.
The bottom-up short-term measurement method utilizes site measurements to provide more
accurate operational schedules. The end use was divided into seasonal end use (HVAC) and non-
seasonal end use (lighting, hot water and others) by David Robison (1992). The non-seasonal end
use energy usage could be collected by site measurement, and its annual consumption can be
obtained by simply multiplying the weekly energy use by the number of working weeks throughout
the year. The seasonal end use could then be calculated by subtracting the non-seasonal end use
from the whole year energy consumption.
The top-down disaggregation algorithm was developed by the Lawrence Berkeley Laboratory and
divides the building end use into three different types of end use, which comprise of HVAC,
26

lighting, and a miscellaneous type. There are two constraints for this method; first, the sum of each
building’s end use should be equal to the collected whole building’s end use. Second, the
load/temperature relationship is then used to characterize the air conditioning end use and to
provide the constraints for the remaining end use. There are two steps in this method. The DOE
program and site survey/data are used to draw the initial end use profile. Simultaneously, the
load/temperature profile is established through the simulations. The second step is to adjust the
initial distribution profile iteratively according to the two constraints (Hashem Akbari, 1995).
While energy bills could only provide the whole building’s energy consumption, the monitoring-
based method includes end-use sub-metering and building management system (BMS) based
methods that could provide a more detailed end-user method with higher accuracy through
complex sub-metering system and platforms.
2.1.2.3 Hybrid method
The Hybrid quantification method relies heavily on calculation analysis but uses the measurements
as supplemental information in order to the decrease the discrepancies between the predicted and
the actual building’s energy consumption. The calibration methods and dynamic inverse modelling
are two common such methods.
The calibration method aims to tune the estimated value inputs in the simulation model to make
the predicted result more closely resemble the actual energy data. The energy calibration process
can be very complex depending on the system types used in the building, but generally the inputs
are obtained from three sources: (1) building as-built drawings and documentation, (2)
walkthrough and energy audit, and (3) end-use measurements. Comparing building model inputs
with the information collected above could increase the accuracy of the building energy prediction.
The training data for the steady-state model is acquired from a detailed simulation or an onsite
survey in the existing building while the training data for the dynamic inverse model is obtained
from in-situ measurements. The dynamic models can simulate the dynamic effects of such thermal
mass, which requires a set of differential equations. However, the dynamic models are becoming
increasingly complex, and it requires a more detailed data to in order to tune the model. One typical
example of a dynamic inverse model is the artificial neural networks (ANN), which implements
methods such as non-linear regression to model the building (Abraham Yezioro, 2007).
2.1.2.4 Conclusions
Among energy quantification methods illustrated above, a hybrid method would be used for the
case study of this thesis since it combines the features of calculation-based and measurement-based
methods, which offers more flexibility for the energy quantification of existing buildings. The
calculation-based method could be very powerful in generating detailed simulation outputs
through simulation tools. However, for an existing building, the availability of all the input data
required by the calculation-based method could be problematic since it is challenging to collect all
the system parameters and performance data. The energy bill collected through the measurement-
based method could directly indicate the building energy consumption in each end use, which
could be further used to calibrate the building simulation result.
27

2.1.3 Energy quantification tools
There are multiple software tools available in the market to conduct energy simulation; however,
currently there is no software that particularly meets the requirement of building retrofits in terms
of energy analysis and cost. As such, tendencies can be observed but there is a lack of consistency.
Excel tools based on EN ISO 13790 calculation methodologies were used for energy demand
simulation on a retrofitting evaluation of existing Swedish residential buildings (Qian Wang, 2014).
Design builder was used to build geometries and EnergyPlus was used to conduct dynamic energy
simulation for a variety of ECMs of UK school building retrofit studies. (Jamie Bull, 2014)
TRNSYS was used for calculating the energy savings of energy refurbishment scenarios for a
university hospital building in Italy (Annamaria, 2014), and it was also used for an existing
historical building retrofit in southern Italy (Giovanni, 2015). This software includes detailed
HVAC component models which are validated against experimental data. A large library of
weather data is further embedded in this software. The 3D model was first created in SketchUp
and then imported into TRNSYS (Annamaria, 2014). A web-based platform to support the energy
efficiency program in a city scale was built by Lawrence Berkeley National Laboratory, and
EnergyPlus was used as its energy modeling engine. EnergyPlus includes around 800,000 lines of
/C++ code, and it was validated using test cases from ASHRAE standards (Tianzhen Hong, 2016).
There are several recommendations for energy analysis software selection provided in the report
of “Improving California’s Multifamily Buildings: Opportunities and recommendations for Green
Retrofit & Rehab Programs” by the multifamily subcommittee of the California Home Energy
Retrofit Coordinating Committee (2011). A code compliance software is chosen to establish the
baseline reference model while a supplementary software is used to assist the energy savings
analysis. In California, the Title 24 energy code compliance software has been commonly used for
conducting energy savings documentation of energy code compliance and incentives/green
building program compliance. The calculation-based method utilized in the title 24 compliance
software is called the alternative calculation method (ACM) manual. Although code compliance
software has its own limitations, limited measures which are considered cost-effective are included
in the energy code compliance software and operational savings which could be calculated through
other energy audit software but are not included in the energy code compliance software. However,
it is still recommended to use the code compliance software as the tool for building upgrades for
two reasons. First, code compliance software provides standardized assumptions and baselines
which are aligned with the energy code for new constructions. Second, there are a large number of
professionals who are familiar with the code compliance software.
Currently, there are several different types of approved computer compliance programs used for
2016 (the latest) Building Energy Efficiency Standards compliance. For residential buildings,
CBECC-Res, EnergyPro, and Right-Energy Title 24 are approved to be used as the energy code
compliance programs while the CBECC-com, IES Virtual Environment, and EnergyPro are
approved for conducting energy code compliance for nonresidential buildings (California Energy
Commission, 2016).
28

IES VE is used for this thesis because unlike EnergyPro, which is used specifically for building
code compliances, IES VE could also provide thermal comfort analysis, daylighting control, and
incorporating control system for the building systems.
2.2 Case studies on ECMs selection of institutional buildings in California
2.2.1 HVAC retrofit
To promote and advocate the sustainable building design and operations for UC Berkeley’s
campus and other universities, the Green Building Research Center (GBRC) in UC Berkeley was
founded to provide resources and case studies related to sustainable building design and retrofits.
The energy retrofit measures for a few of the projects and its benefits are summarized below.
The University of California Davis, Plant and Environmental Science (PES) Lab Energy Retrofit
was one of the projects once awarded as the best HVAC Design/Retrofit. The initial HVAC
installed in the building consists of five air handling units with constant air volume. (GBRC, 2014)
80% of the rooms in this building are laboratories, and due to safety issues, the ventilation
requirements are very high in this building and a high fan power is required to maintain a high air
flow rate. At the same time, certain air temperatures are required to be maintained in order to
achieve the thermal comfort. These two factors contribute to the significant energy consumption.
Investigations on the building’s operational conditions were conducted to ascertain the energy
savings potentials in the buildings. The occupancy levels inside the building were monitored and
the ventilation rates of the HVAC systems were verified. To reduce excessive energy consumption
by the HVAC systems, several retrofit measures were adopted based on the investigations. VFDs
(variable frequency drives) were installed for the supply and exhaust fans to reduce the ventilation
rate and the energy of the fan when the building is unoccupied. Also, the motor of the fan in the
buildings is replaced by one with a higher efficiency, and the direct digital controls are installed to
provide wider range of temperature control and reduced the ventilation rate when the building is
unoccupied. The adoption of these retrofit measures resulted in 36% in energy savings.
The University of California, San Diego cognitive science also did an HVAC retrofit to meet the
new ventilation requirements due to building space type transformation. Formerly, the building
was used as a laboratory but was converted into office spaces throughout the years. Electrical
meters were installed to gather the energy consumption of the baseline model and the real-time
data of the energy consumption were analyzed for retrofit measure selection. The office requires
much less ventilation rates than the laboratory; thus, two 2,500 cfm AHU’s were replaced by a
single 3,000 cfm AHU. Excessive fume hoods and the exhaust fan for the laboratory were removed
in order to reduce the fan’s energy consumption. The variable frequency drives were installed to
provide variable air volume with a wider temperature range. This cognitive science building was
also a part of the load shed programming program that could reduce the electrical demand at the
peak hours. The cost for the retrofit project is $150,000 and the annual cost savings by energy
savings are $29,600 (GBRC, 2006).
The Naraghi Hall of Science at Cal State University Stanislaus is a 110,000-sqft, three-story
building that was first built in 2007 and has had a LEED silver certification. It consists 25
laboratories, 59 offices, 16 science rooms and 4 classrooms. Although the building was LEED
29

certificated, the commissioning and the system upgrading are necessary to improve the building’s
energy efficiency. Through the building performance assessment, it was found that the HVAC
system in the laboratory was operating 24 hours per day with constant air, which results in high
energy consumption. The high volume of ventilation rate was designed to remove the dangerous
chemical substances in the air; however, it was not necessary to have the high volume of ventilation
rate when there is no hazardous gas or substances. To decrease the energy consumption resulting
from the laboratory ventilation, sensors designed to measure the level of contaminants were
installed to assist the ventilation systems and provide maximum ventilation rates when the
contaminants in the air was detected by the sensors. The sensors were connected with building
management system, which controls all of the building’s systems including the HVAC systems.
Additionally, variable frequency drives were installed to maintain the indoor thermal comfort. The
minimum flow of the fume hood was also reduced to those levels permitted by the Z9.5 standards
in American National Standards Institute (ANSI). These retrofit measures significantly reduced
the fan’s energy as well as the annual electricity by 549 MWh and the natural gas by 22,400 therms
(GBRC, 2014).
2.2.2 Lighting retrofit
To reduce the lighting energy consumption by 60%-80% before 2020 (required by California
Public Utilities Commission), UC Davis has established the Smart Lighting Initiative to reduce the
lighting energy consumption by at least 60% compared with 2007 levels. There are several
problems related to the outdoor lighting at the UC Davis Campus, one of which is a lack of both
occupancy and scheduling controls to save the energy at night. The energy audit for the exterior
lighting was conducted and one-to-one retrofit suggestion were given. LED products and advanced
wireless controls were proposed as a are part of the solution. The pricing and lighting fixtures were
collected and economic analyses were conducted. It was found that RoadStar street and area fixture
produced by Philips Lumec is the most cost-effective product. There were 86 post-top fixtures,
101 wall packs, and 1,347 roadway and area fixtures replaced for the retrofitting case. These new
products significantly decrease the lighting consumption. For example, the new LED fixtures
installed in the roadway/street reduces the lighting consumption by 73% when assisted with
wireless occupancy control. The overall lighting retrofit for the UC Davis has reduced the outdoor
lighting by 86% and reduced the maintenance savings significantly.
2.2.3 A summary of retrofit examples
The majority of the school building retrofit cases in California are the HVAC and lighting retrofits
including interior and exterior lighting, both of which are summarized below (GBRC, 2014).
There are also other strategies such as incorporating daylighting and natural ventilations.

30

Table 2.1: Summary of school buildings retrofit in California (GBRC, 2014).
Name
Retrofit
Type
Retrofit Options Energy Savings
Operation
al cost
savings/ye
are in $US
investment cost
in $US
CSU Dominguez
Hills (2016)
HVAC Install advanced chilled water valves
cooling energy 11%
reduction for student
health center; 22% for
welch hall
19,600
25,000
(manufacturer
donate)
UC Davis Plant and
Environment
Science Lab Energy
Retrofit (2013)
HVAC
Occupancy sensors based HVAC control
36% 138,000 N/A
VFDs on supply and exhaust fan
Upgrade direct digital control system
Atkinson Hall, UC
San Diego
（2016 ）
HVAC
Reduce overcooling in offices
26% 230,200
526,400
(including 484k
incentives)
Adjust minimum airflow rates
Repair economizer failure
Cal State
Sacramento
（2016 ）
Lighting
Replace fluorescent fixtures with LED
50% (below 2013 title 24,
213000 kWh energy
savings)
22,250 367,000
Advanced wireless lighting control
system
Advanced daylighting control: dimming,
daylight harvesting, occupancy control
UC Santa Barbara
（2016 ）
Lighting
Replace fluorescent fixtures with LED
60% below previous
usage (54% below Title
24); 171,000 kWh energy
savings
18,800
223,000 (47,870
utility incentives)
Advanced wireless lighting control
system
Motion sensors, occupancy sensors,
dimming sensors for unoccupied times
Cal Poly San Luis
Obispo chilled
water pumping and
central plant
optimizatio
（2015 ）
HVAC
Optimization of chiller plan operation
electricial sacings 1,000
MWh, gas savings:
47,000 therms
12,800
1.4 M (252,000
in utility rebates)
VFDs on supply and exhaust fan
Upgraded boilers
UCSF Animal
research building
monitoring based
commissioning
（2015 ）
HVAC
BMS system to optimize ventilation and
space conditioning on room needs
verified electrical
savings: 1440 MWh
(50% reduction), gas
savings 48200 therms
21,8000
510,030 (393,900
incentives)
CSU Fullerton
（2015 ）
Lighting
occupancy sensors installed to throttle
back ventilation during unoccupied times
4,000 MWh 520,000
1M including
500,000 SCE
incentives
Replace fluorescent fixtures with LED
Advanced lighting controls
UC Santa Cruz
Mchenry Library
（2015 ）
Lighting
Replace fluorescent fixtures with LED
550,000 kWh 65,000
698,500 (40,000
PG&E
incentives) Install occupancy sensors
31

San Jose State
University
（2015 ）
HVAC
Change constant air volume into variable
air volume system
Electrical savings:
680,887 kWh (10%
reduction); natural gas
savings: 369,247 therms
(87% reduction)
319,000
5.5 million
(including
532000
incentives)
CSU exterior
lighting upgrade
with 3 major
campus buildings
（2015 ）
Lighting
LED fixtures
101,200 kWh/year 12,600 77,950
Reduction of fixture quantity
Networked wireless controls for
occupancy and demand response
UC Irvine
（2013 ）
Lighting
LED fixtures
972,000 kWh/year 126,400 336,000
Dimming control
CSU Stainislaus
Naraghi Hall Lab
ventilation
improvement
（2014 ）
HVAC VFDs on fan
549 MWh electricity,
22,400 therms gas
73,800
190,000 (50,000
incentives)
UC Santa Cruz
Laboratory
（2014 ）
lighting
Occupancy sensors, daylighting harvest
(daylighting sensors)
255,700 kWh (40% to
70% energy reduction)
255,700 34,520
Wireless lighting control
CSU lighting
controls retrofit
（2014 ）
Lighting
Wireless lighting control technology,
based on occupancy and daylighting
sensitive controls
200,000 kWh （50% to
78%)
26,000 50,000
UC San Diego
Pacific Hall
Laboratory HVAC
retrofit （2014 ）
HVAC
CAV to VAV; VFDs on fan
3,853 MWh, 372,821
therms
801,640 0.93 million
Recalibration of required airflow
requirement
Install occupancy sensors
CSU Stainislaus
central plant and
chilled/hot water
optimization
（2012 ）
HVAC
Altered piping design to reduce bypass
213,998 kWh/yr 39,000 $235,777
Replaced three-way valves with two-way
valves
Improved temperature differential and
reduced chilled and hot water volume
UC Davis Adaptive
Controls for
Exterior Lighting
（2012 ）
Lighting
Occupancy sensors and centralized
network system
1,000 MWh 100,000 $950,000
LED products
UC San Diego
HVAC Controls
Retrofit at Geisel
Librar （2012 ）
HVAC
Variable frequency drives (VFDs)
installed on 32 fans, CAV to VAV Electricity: 1,580 MWh
Natural gas: 103,300
therms
280,000 $1.1 million
New motors installed where needed
Advanced software controls
2.2.4 Conclusions
It could be seen from the previous cases of intuitional building retrofits in California that HVAC
and lighting retrofits are the two most common energy conservation measures for energy retrofits.
For the HVAC retrofit, changing the fan from a constant to a variable volume, adding a variable
speed drive, downsizing the ventilation equipment, reducing the ventilation rate, and installing
sensors along with advanced controls are the five main measures. For the lighting retrofit,
replacing the existing lighting equipment with LED lights and adding lighting sensors along with
advanced controls will significantly improve the energy efficiency.
32

2.3 Economic analysis
2.3.1 Introduction
The discounted cashflow method is the most common technique which is involved in the economic
analysis of building retrofits.
2.3.2 Discounted cashflow method
Discounted cashflow (DCF) method provides a dynamic investment analysis for comparing
energy-efficient retrofit packages for a building; furthermore, it provides investors a quantitative
basis to make rational decisions. In this method, the future cash flow is discounted to those of the
present time values so that it is comparable with the current investment expenditures. The net
present value is one of the indicators for the discounted cash flow method. Other indicators include
the internal rate of return (IRR) and the payback period (PBP). All of the indicators could be
derived from the same equation shown below (Amstalden Roger W, 2007)
NPV = ∑ 𝑐 𝑓 𝑡 (1 + 𝑖 )
−𝑡 𝑇 𝑡 =0

T: useful life of the investment
i: discounted rate
𝑐𝑓 𝑡 : cash flow at time t, 𝑐𝑓 𝑡 < 0 indicates earnings, , 𝑐𝑓 𝑡 > 0 indicates expenditures
2.3.3 Lifecycle cost analysis (LCCA)
LCCA could be used to provide economic performance evaluation of the building over its lifetime,
including the initial cost, the long-term expenses such as maintenance, and the operational cost. It
could facilitate comparisons between different design options to explore the trade-offs between
the low initial cost and the long-term savings in cost. Through comparisons, the most cost-
effectiveness system for a certain usage could be selected and the time to pay back the initial cost
of a specific system could be calculated. Conducting a lifecycle cost estimation for each design
element of a building with an exhaustive lifetime is impractical, so it is crucial to define the
boundary of the lifecycle cost analysis (Stanford University Land and Buildings, 2005).
2.3.3.1 Lifecycle cost (LCC) pattern
A chart of life-cycle cost over the 30 year-life-span of a building is illustrated below. It can be seen
that the initial cost of the building accounts for 37.7% of the life-cycle cost over the 30-year time
period while the utility cost and the maintenance cost accounts for 28% and 6%, respectively, of
the life-cycle cost during the same timeframe.
33

Figure 2.2: Lifecycle cost pattern (SULB, 2005)
2.3.3.2 LCCA decision matrix
An LCCA decision matrix is developed to assist the selection of the most cost-effective design
options. The vertical axis of the graph illustrated below represents the potential impact of the cost
while the horizonal axis represents the complexity of the analysis required. It is recommended that
the categories in quadrant I be issued the highest priority. The prioritization sequence is as follows:
quadrant I > quadrant II > quadrant III > quadrant IV. (SULB, 2005)

Figure 2.3: LCCA decision matrix (SULB, 2005)

34

2.3.3.3 Steps for the LCCA process
Step 1: Establishing the LCCA objectives
It is important to establish clear objectives for the LCCA studies. LCCA could only analyze cost-
related subjects; thus, it would not be the correct tool to assist human comfort-related analysis.
Step 2: Determination of the LCCA metrics (total cost and payback)
The total cost and the payback period is the most common metrics used to calculate the LCCA.
Step 3: The base case and determination of alternative designs
The base case is defined as the standard design or the minimum requirement for the project.
Alternative designs should be developed against the base case.
Step 4: Gather information regarding the cost
Information regarding cost could be obtained from designers, vendors, experts specializing in
cost-estimation, and contractors. The components of the life-cycle cost are further elaborated in
the following paragraphs.
Step 5: Perform life-cycle cost calculations.
The life-cycle cost calculations could be conducted based on the information regarding the cost
obtained previously in step 4.
2.3.3.4 Components of LCC (SULB, 2005)
• Project cost
The project cost, also known as the initial or the first cost, includes the cost of construction such
as labor, materials, equipment, furnishings etc. There are also “soft” costs such as design and
permit fees. The differences in cost between the alternatives are more crucial than the absolute cost
in LCCA analysis. It is recommended to thoroughly consider the variations in cost between
different alternative.
• Cost of energy-dependent and non-dependent utilities
There is a cost for each utility service
• Cost of maintenance
The cost of maintenance is defined as the cost that contributes to maintain the proper function of
building systems.
• Cost of service cost & Cost of remodeling
Expenses such as janitorial services, pest control, elevator maintenance all fall under the realm of
service costs. Service cost and remodeling cost may or may not be included in the LCCA
analysis depending on the decision of the project team.
35

• Residual value
Usually the residual value of the building is assumed to be zero.
• Demolition
If demolition is required among the different alternatives in consideration, it is appropriate to
include the cost of demolition.
2.3.3.5 Fundamental concepts related to life cycle cost
• Time value of money
The time value of money is the concept that the current worth of a given amount of money will
differ from the same amount in the future. The two factors influencing the time value of money
are inflation and opportunity cost.
• Inflation
The value or the purchasing power of money would be reduced due to inflation. It results from
the gradual increase of goods and services due to economic activities.
REAL =
1 + 𝑁𝑂𝑀𝐼𝑁𝐴𝐿 1 + 𝐼𝑁𝐹𝐿𝐴𝑇𝐼𝑂𝑁 − 1
Real: real rate
Nominal: nominal rate
Inflation: inflation rate

• Discount
The cost of the project at different times during the lifetime of a building needs to be discounted
back to the present value for comparison purposes. The equation for determining the amount of
discount is indicated below:
PV =
𝐹 𝑌 (1 + 𝐷𝐼𝑆𝐶 )
𝑌
PV: present value
𝐹 𝑌 : value in Y years (future)
DISC: discount rate
Y: number of years
Uncertainty in LCCA calculations
Assumptions in LCCA calculations
36

• Escalation
Although the rate of price changes of goods and service might not be same as that of inflation, it
will approach the rate inflation over time.
𝐶𝑂𝑆𝑇 𝑌𝐸𝐴𝑅 −𝑌 = 𝐶𝑂𝑆𝑇 𝑌𝐸𝐴𝑅 −0
(1 + 𝐸𝑆𝐶 )
𝑌
𝐶𝑂𝑆𝑇 𝑌𝐸𝐴 𝑅 −𝑌 : cost in the future Year Y
ESC: escalation rate
Y: number of years in the future

The following equation is recommended to be used:
LCC = C + 𝑃𝑉 𝑅𝐸𝐶𝑈𝑅𝑅𝐼𝑁𝐺 − 𝑃𝑉 𝑅𝐸𝑆𝐼𝐷𝑈𝐴𝐿 −𝑉𝐴𝐿𝑈𝐸
LCC: life cycle cost
C: construction cost at Year 0
𝑃𝑉 𝑅𝐸𝐶𝑈𝑅𝑅𝐼𝑁𝐺 : the present value of all recurring costs (including the cost of utilities, maintenance,
replacement, service, etc.)
𝑃𝑉 𝑅𝐸𝑆𝐼𝐷𝑈𝐴𝐿 −𝑉𝐴𝐿𝑈𝐸 : the present value of the residual value at the end of the building’s life time. It
is suggested to be 0 based on the guidelines.
2.3.3.6 Energy cost
The California Electric and Gas Utility Cost Report published by the California Public Utilities
Commission (CPUC) (2017) provides an analysis for the electric utility costs of the four major
California investor-owned utilities (IOU): Pacific Gas & Electric (PG&E), Southern California
Edison (SCE), San Diego Gas & Electric (SDG&E), and Southern California Gas Company
(SocalGas).
It can be seen from the table that the system average rate of the cost of electric utilities generally
increased from 2005 to 2016. From 2012 to 2016, the average annual increasing rate of system
average rates (SAR) in the three IOUs reached approximately 3.44%, which is higher than the
average annual inflation rate of 1.3% during the same time period. In 2016, it can be seen that the
cost of electric utilities is 14.9 cents per kWh, while those for PG&E and SDG&E are 18.28, and
20.54 cents per kWh, respectively (CPUC, 2017).

37

Table 2.2: Trends in average rates of electric utility costs (CPUC,2017)

Table 2.3: System average rates of costs of electric utilities from 2012 to 2016 (CPUC, 2017)

The average energy prices published by the United States Department of Labor (2017) shows
that the average electricity rate in the greater Los Angeles area during 2017 is 0.18 dollars per
kWh while the average piped natural gas during the same year is 1.0 dollars per therm.
Table 2.4: Average prices for gasoline, electricity and utility (piped) gas, Los Angeles -
Riverside - Orange County and the United States, November 2016 (USDL, 2017)

38

2.3.4 Relevant research
2.3.4.1 Relevant research 1
Both energy cost savings and lifecycle cost savings (LCC) were used to evaluate the economic
benefits for different retrofit approaches in a Hawaiian Building case study. It was proved that the
integrated system approach has the greatest LCC cost savings potentials over a long-term operation
(20-30 years) as compared to traditional building retrofits, which emphasize equipment upgrades.
The discounted cash flow system was used to evaluate the energy savings. The LCC for this
research was defined as the sum of ECM investment cost and NPV as indicated in the equation
below. The ECM investment cost will be able to be paid back within the ECM lifetime if the LCC
is greater than 0. However, when the LCC is less than 0, the ECM investment cost will not be able
to be paid back.
LCC = ECM investment cost + NPV
The escalation rate for energy cost is defined as 5.6% and the discount rate is defined as 5%
according to the data of the case building. The ECM investment cost estimation for this research
was performed by professionals through several different resources, including RSMeans cost
database, DOE CALIPER program, and HVAC manufacturers. For the LCC calculation in this
research, the cost related to material and installation were included while the shipping costs were
not included. Also, due to the complexity of calculating the embodies energy cost from the
production and transportation, these two terms were not included for LCC calculation. Another
limitation of this research is that the improvement in thermal comfort, indoor air quality, and noise
control, all of which fall under non-energy profits, are not quantifiable for this research. The
production and transportation energy related costs will reduce the benefits of retrofit measures
while the non-energy benefits will offset the retrofit cost. Furthermore, the building envelope
upgrade in the IS retrofit will prolong the lifetime of the building; however, this type of benefits
might only be more significant when compared to traditional building retrofit in a longer timeframe
such as 30 to 50 years. (Cythia Regnier, 2017).
In this research, the LCC analysis and energy cost analysis are approved to be applicable to
evaluate the economic benefits of deep energy retrofits/integrated building retrofits. Thus, these
two terms will be adopted in my research to provide economic analysis for the retrofit measures
analysis. The baseline model for the research is created based on ASHREA, while Title 24 would
be the referenced standard for the case study of this thesis. Also, it is addressed in the future work
of this research that creating packages of integrated technologies would assist more streamlined
access to integrated retrofit approach. My thesis will focus more sets of comparison of different
integrated retrofit studies.

39

Table 2.5: Cost summary for three retrofit approaches

2.3.4.2 Relevant research 2:
Qian Wang (2014) adopted lifecycle cost analysis to provide retrofit decision-making rankings for
existing Swedish residential buildings taking into consideration energy savings and long-term cost-
effectiveness. It was pointed out that building retrofits with the highest energy-savings might not
be cost-effective. Three cost factors were involved in calculating the lifecycle cost, which are the
retrofit investment cost (IC), the energy operational cost (OC), and the repair and maintenance
cost (RMC). The retrofit investment cost was attained from standards of building industry. End-
of-life-management were not included for LCC calculations. The equation given below was
introduced to evaluate cost rankings of each retrofit option:

P: normalization factor
This paper presented a very comprehensive and logical methodology for building retrofitting
evaluation in terms of long term economic estimates, which could be referenced to develop the
method of my thesis. One limitation of this research is that the different archetypes were used
instead of real buildings and that there was no benchmark to develop any archetypes. To avoid the
uncertainties brought about by archetype buildings, real building will be used as case study for my
thesis. Although the cost rankings could provide the most cost-effective building retrofit options,
the adoption of all building retrofit options of higher ranks will not ensure the highest energy
savings or net zero building due to the concurrent effects. Lastly, the real energy price changes
and the discount rate variations increased the uncertainties of lifecycle cost analysis.
40

Figure 2.4: Method diagram (Qian Wang, 2014)
2.3.5 Conclusions
LCC and net present value have been approved to be effective techniques for building retrofit cost
evaluations. In terms of ECMs selection, differing from building retrofit cases in industry which
mainly focusing on HVAC and lighting retrofit, the recent research places more emphasis on
integrated approach in order to improve energy efficiency. In the integrated approach, the building
envelope and glazing upgrade were considered in the ECMs options. Different combinations of
ECMs were compared and ranked with energy savings analysis and lifecycle cost analysis. The
integrated approach has been approved to have more cost benefits in a long-term perspective.

41

3. Method of energy savings and economic analysis
3.1 Introduction
The ECM selection for building retrofit is a multi-objective process and it is difficult for building
owners to evaluate the potential benefits brought by different ECMs and choose the optimum
building retrofit cases. This thesis presents a new methodology which utilize the building energy
simulation tool (IES VE) and lifecycle cost analysis to evaluate the energy savings and cost savings
capabilities of different energy conservation measures.
3.1.1 Problem of current methodologies and proposed methodology
It is difficult to select the optimal building retrofit alternative considering the energy efficiency
and cost effectiveness for building retrofit. To provide economic analysis of different building
retrofit scenarios, lifecycle cost analysis and discounted cashflow has been introduced in many
studies. However, less research has explored the influence of a single retrofit on energy savings
and cost savings over a long-term perspective. The new methodology proposes a work flow of
provide energy savings and lifecycle cost analysis for better energy savings measures selection.
An energy ranking model and cost-effectiveness model which was introduced by Qian Wang (2014)
will be used in this research to test its capability of assisting retrofit option selection. These two
models assist quantifying and comparing the energy saving and energy cost savings capabilities of
single retrofit options. The details of the two models are illustrated in the section 3.5.

Figure 3.1: Current methodology Figure 3.2: Proposed methodology
3.1.2 Overall workflow development
There are generally four steps involved in this research. Step 1 is collecting the existing building
information, including building envelope, building systems, energy consumption and indoor
thermal comfort. This step reveals the problems of existing building conditions and existing
building info is the basis of proposing building retrofit plans. After collecting and evaluating the
current building information, the next step is proposing retrofit options and cases for comparisons.
The energy demand rankings and cost ranking model will be used for assisting the single retrofit
option selection and comparison in a long-term energy and cost savings perspective. These two
models will be further explained in the section 3.5. Step 3 is conducting the energy simulation on
building retrofit options to evaluate the energy saving capability. The details of simulation process
are thoroughly explained in the section 3.4. In the step 4. The cost for the retrofit option/energy
conservation measures (ECM), energy cost, repair and maintenance cost would be collected for
conducting lifecycle cost analysis.
42

Figure 3.3: Overall workflow development
3.2 Existing building information collection and analysis

3.2.1 Introduction
The existing building information includes local weather information, existing architectural
drawings, building materials, MEP systems, building energy and indoor thermal comfort.The
weather information is obtained from the climate consultant to understand the historical weather
information. The information related to architectural drawings, building materials and existing
building MEP system were collected from the building manager. An onsite visit was conducted to
validate the as built drawings. In order to evaluate the indoor thermal comfort, several sensors
were located in the different façade of the buildings to collect the indoor temperature and humidity.
The building overall conditions was summarized at the end of this chapter.
3.2.2 Existing building information collection

3.2.2.1 Location and weather information
It is shown in Climate Consultant 6.0 that UCLA graduate art studios is located in Climate zone 8
and 7.4 miles away from the Los Angeles International Airport (Climate zone 6). It is indicated
that the hottest outdoor temperature is 95 °F in September based on the historical data. The coldest
temperature of climate zone 8 reaches down to 35°F (January).
43

Figure 3.4: Weather information of climate zone 8 (Climate Consultant 6.0)
The psychrometric chart shows that only 12.2% is within in comfortable zone. The major design
strategies which help achieve the indoor thermal comfort is internal heat gains, passive solar direct
gain and heating, etc.

Figure 3.5: Psychrometric chart for climate zone 8 (Climate Consultant 6.0)

44

3.2.2.2 Existing architecture drawings
The existing floor plan and new floor plan were obtained from the Architectural firm (Johnston
Marklee) who worked on the project. The elevation plan was not available. Thus, room height,
dimensions related to exterior glazing and doors were obtained through onsite investigation and
measurement.

Figure 3.6: Existing floor plan
According to the owner’s requirement, this building retrofit project will consist of a renovation of
20800 square feet of former studio area and the area for expansion is 18500 square feet. The plans
for demolition and renovation are shown below. The blue area which is former studio area is the
renovated area while the green area of existing building will be demolished.
45

Figure 3.7: Existing floor plan
46

The proposed new building floor plans are shown here:

Figure 3.8: New floor plan
3.2.2.3 Existing building materials
The existing building construction and its material properties were collected from existing
documentation and validated through onsite observations. The details of the collected information
are displayed below.
Table 3.1: Existing building materials
Construction type U value (Btu/h.ft
2
/F
°
)
Exterior Wall 4” cast in place concrete wall
with elastomeric coating (140
lb./ ft
3
)
0.873
Existing Non-bearing
Partition Wall
Wood Panel 0.64
Roof Wood framed vaulted roof 0.075
Ground floor Concrete slab on grade N/A
Glazing (only existed in the
demolished area)
Double pane 0.7
Door Insulated Steel 0.65

47

Figure 3.9: Photos of existing building envelope
3.2.3.4 Existing MEP drawings
The detailed information of mechanical, electrical and plumbing system was collected from the
MEP design firm (ME Engineers) and building manager.
• HVAC system
The existing ventilation system includes three rooftop fans and 5 12-inch wind-driven turbine
ventilators. There are three huge fans which each of them can provide maximum 8000 cfm, but
they are not functioning anymore. With a speed of 4 mph, the turbine ventilator can remove 631
cfm from the attic space. The ventilation system is only located for the studio area.
Table 3.2: Existing HVAC system
Mechanical
Equipment
Description Amount Location Condition
Exhaust Fans 8000 cfm
(Maximum)
Ventilation
Only
3 Studio Not
working
Electricity
Wind turbine
ventilators
631 @4mph 5 Studio Working Wind
Air
conditioner
Heating and
cooling not
known
4 Wet lab, Digital Lab
(first floor), Digital Lab
(second floor), Office
Working Electricity
Infrared
Radiant
heater
50,000 BTU
Model
number: DTH
20-50 N-2
6 Studio Working Natural
gas
Air forced
heater
Not known Studio Working

48

• Lighting systems
The existing lighting layout was validated through onsite visit and it is shown below. There are
five types of the fluorescent lighting fixture involved in the existing building. The lighting plan
was collected from the building manager and it was validated by onsite observations. During the
several sites visits, all the lighting in the corridors are opened whole day and studios lighting were
controlled by students. The lighting systems for each studio is manually controlled by the students.

Figure 3.10: Existing lighting fixture layout
• Other system information
Detailed electrical and plumbing systems were not provided.
3.2.2.5 Building energy consumption and utility data
49

The building energy consumption data was collected from UCLA campus. Only electricity and
natural gas consumption in 2015 and 2016 were available for analysis. The existing building EUI
is 24 kBtu/ft2/year.
• Building monthly electricity
The electricity usage of year 2015 and 2016 present similar tendencies. The electricity usage
slightly decreased during the month of June July and August due to the less student activity during
the summer vocation. The electricity usage gradually increases after September, which was result
of increasing student activity during project due season.

Figure 3.11: Monthly electricity consumption in 2015 and 2016

Figure 3.12: Monthly electricity bills in 2015 and 2016
50

• Building monthly natural gas
Figure 3.13 and Figure 3.14 indicates the existing natural gas consumption and bills information
in 2015 and 2016. The natural gas usage is related to two equipment. Gas kiln and indoor radian
heater inside the buildings.

Figure 3.13: Monthly natural gas consumption (therms) in 2015 and 2016

Figure 3.14: Monthly natural gas bills in 2015 and 2016

51

• Building monthly water usage
Figure 3.15 and Figure 3.16 shows the information related to water consumption in 2015 and
2016.

Figure 3.15: Monthly water consumption in 2015 and 2016

Figure 3.16: Monthly water bills in 2015 and 2016

52

3.2.2.6 Indoor thermal comfort
• Indoor temperature & Humidity collection
In order to know the existing indoor thermal information, four HOBO sensors were placed in the
studio area to collect the indoor air temperature and air humidity while one HOBO is placed
outdoor to collect the outdoor air temperature and humidity data. The height of the sensors to the
ground are approximately 1.5 meters. Area with direct sunlight and indirect sunlight were avoided
for all indoor sensor locations. The outdoor sensors are placed at the shaded area. The sensors are
installed during Oct 23th 2017 and December 15
th
2017. Two weeks of data is collected now and
it is shown below. The data logger is collecting data every 10 minutes.
The outdoor temperature reached the highest at 101.4 °F on Oct 24
th
and the minimum outdoor
temperature collected is 56.75 °F. During the hottest day (Oct 24
th
), all the temperature of the
rooms reached the peak; the average temperature of the rooms is 94.3 °F. During the early morning
of November 4
th
(7:00 am to 8:00 am), the outdoor temperature drops to the coldest, which is
around 57°F. The average indoor temperature dropped down to 67 °F during the coldest time.

Figure 3.17: Air temperature in five locations

Figure 3.18: Air humidity in five locations
53

3.2.2.7 Existing building condition summary
• Building Envelope
The exterior walls of the building are poorly insulated and the indoor thermal environment
(temperature/humidity) is not well controlled due to the malfunction of existing mechanical
systems. There are several openings/holes in the building envelope which provide natural
ventilation for the hallways near the openings but it also significantly decreases the air-tightness
of the buildings. As a result, the indoor environment is not rigorously controlled and it is not
thermal comfortable. The temperature in the early morning could decreases to 57°F during the
cold days and rises up to 97°F during the hot days.
• Building mechanical system
Currently the building is only mechanically ventilated assisted with 5 wind turbine ventilators.
Based on the 2016 California mechanical code, existing building mechanical design did not
provide enough ventilation for all the occupancy in the studio area. Heating is not sufficient for
cold days while the cooling system needs to be added for the building to provide cool air for hot
days.
• Lighting system
The lighting system in the existing building are all fluorescent lighting. Lighting located in the
corridor are turned on even when there is no occupancy in the building. It is suggested LED
lighting and lighting control strategies should be applied to improve the energy efficiency.
• Building occupancy
There are 40 students and one building manager in the studio and the time when all the students
come to studio varies depend on their own schedules and timeline of project, which adds difficulty
to determine the occupancy level in the building. Assumptions for occupancy level and schedules
are made based on observations.
3.3 Propose specific ECMs
3.3.1 Baseline model descriptions
There have been a lot of considerations when creating the baseline model for this research. The
baseline model has incorporated many existing building information but not exactly the same as
the existing building. There are several reasons for not using the existing building as the baseline
model. Firstly, this is different from other retrofitting projects which only involve renovation. This
renovation project also involves expansions as it is illustrated in the previous chapters. Only the
studio area of this project will be renovated and other area of the existing building are all
demolished and replaced with new floor plans. Secondly, the existing building does not have
cooling system (mechanical) and the indoor environment is not thermally comfortable due to the
malfunction of the ventilations systems. The energy consumption of existing building is much
lower than normal institutional buildings which has thermally stable and comfortable indoor
54

environment. It is not fair to compare the energy consumptions of the existing building with other
retrofit cases since the energy consumed by HVAC system is one of the major contributors of the
whole building energy. Thus, several modifications have been made on the existing building,
which are further explained below.
• Building envelope:
The renovated floor plans are used for the baseline model instead of existing building. In terms of
building envelope materials, baseline building exterior of studio is same as the existing buildings
while the external wall of the expansion wall is assumed as bare concrete close to code requirement.
Other building envelope materials presents consistency with existing building information.
• Building lighting systems:
The averaged lighting load is aligned with the existing building information.
• HVAC system:
The other major change of the baseline model is the HVAC system. The existing HVAC system
of building does not comply with the building code and the indoor thermal environment is not
rigorously monitored and controlled. Thus, the baseline model does not use the same HVAC
system as the existing HVAC system. Instead, the baseline model is assumed to use the similar
system type as it is recommended by the MEP design firms, who is re-designing the whole HVAC
system. The HVAC systems used for the baseline building are packaged air conditioner, variable
refrigerant system, split air conditioner and split heat pump systems. These HVAC systems are
also the most commonly used systems for single institutional building, which is isolated from the
main campus and does not have central plant. The details of the baseline building information are
provided below.
N/A: No mandatory requirement in Title 24 California Code

55

Table 3.3: Baseline building information
Building Envelope
Building
Parameter
Description Value Mandatory
Requirement
Prescriptive
Requirement
External Wall 1
(Existing Wall
at studio area)
Light Mass Wall: The existing 4”
concrete of the studio area is
maintained for building renovation.
U value = 0.873 U value ≤0.44 U value ≤0.44
External Wall 2
(Addition Area)

Heavy Mass Wall: New Tilt Up
concrete wall of the addition area.
(140 𝑙𝑏 /𝑓𝑡
3
)
Thickness = 10 inch.
U value = 0.629
U value ≤0.69 U value ≤0.69
Ground Floor Concrete Slab on Grade: the existing
slab is elevated from the adjacent
grade.
U value = 0.003 N/A N/A
Interior Floor Interior Floor/Ceiling U value: 0.188 N/A N/A
Barrel Roof
(Existing)
Conventional single-ply roof assembly
Wood framed (Altered Roof)
U value: 0.082 U value ≤0.82
(Insulation
R=8)
N/A
Barrel Roof
(New)
Wood Framed Roof (Not asphalt
Shingles Roofing)
U value: 0.075 (R19) U value ≤0.075 U value ≤0.049
Solar reflectance:0.1 Solar
reflectance:0.1
Solar reflectance:
0.2
Thermal emittance:0.75 Thermal
emittance:0.75
Thermal
emittance: 0.75
SRI: 16 SRI (N/A) SRI: 16
Skylight Unit skylight above the studio: glass,
curb mounted
Structural skylight above the
additional area
U value= 0.58 N/A U value ≤0.58
SHGC=0.25 N/A SHGC ≤0.25
VT = 49% N/A VT≥49%
Exterior
Window
Fixed window U value= 0.36 N/A U value ≤0.36
SHGC=0.25 N/A SHGC ≤0.25
VT=42% N/A VT≥42%
Interior Wall/
Internal
Partition
Interior wall and demising wall.
Demising wall: wall separates
conditioned space with unconditional
space.
U value: 0.37 No insulation
required.
N/A
Lighting System
Lighting Traditional fluorescent lighting
(Control On/Off)
Averaged Lighting Load:
1W/𝑓𝑡
2

LPD ≥ 1
W/𝑓𝑡
2

N/A
HVAC System: The temperature of the baseline model is controlled between 70°F and 75 °F
Packaged Air
Conditioner 1
& 4
Fully air conditioner: packaged air
conditioner with constant air volume
(DX cooling with gas furnace
heating). Located in Studio Area:
135000 Btu/h≥ Size ≥ 65000 Btu/h
EER = 11.2
IEER = 12.9
E
𝑡 = 80%
Fan efficiency = 70%
Motor efficiency = 90%
EER ≥ 11.2
IEER ≥ 12.9
E
𝑡 ≥ 80%
N/A
Packaged Air
Conditioner 2
Located in studio area
Size ≥ 240000 Btu/h
EER = 10
IEER = 11.6
E
𝑡 = 80%
Fan efficiency = 70%
Motor Efficiency = 90%
EER ≥ 10
IEER ≥ 11.6
E
𝑡 ≥ 80%
N/A
56

Packaged Air
Conditioner 3
Located in studio area
240000 ≥ Size ≥ 135000 Btu/h
EER = 11
IEER = 12.4
E
𝑡 = 80%
Fan efficiency = 70%
Motor Efficiency = 90%
EER ≥ 11
IEER ≥ 12.4
E
𝑡 ≥ 80%
N/A
Packaged Air
Conditioner 5
Located in office areas
135000 Btu/h ≥ Size ≥ 65000 Btu/h
EER = 11.2
IEER = 12.9
E
𝑡 = 80%
Fan efficiency = 70%
Motor efficiency = 90%
EER ≥ 11.2
IEER ≥ 12.9
E
𝑡 ≥ 80%
N/A
Packaged Air
Conditioner 6
Located in office area
135000 Btu/h ≥ Size ≥ 65000 Btu/h
EER = 11.2
IEER = 12.9
E
𝑡 = 80%
Fan efficiency = 70%
Motor efficiency = 90%
EER ≥ 11.2
IEER ≥ 12.9
E
𝑡 ≥ 80%
N/A
Split Heat
Pump
Heating only EER = 9.1
COP = 3.5
N/A N/A
Split Air
Conditioner
1&2
Provide heating and cooling Split AC 1
EER = 9.1
COP = 3.5
Split AC 2
EER = 12.5
COP = 3.7
N/A N/A
Boiler (DHW) The boiler serves to domestic hot
water
Efficiency = 80% Efficiency
≥80%
N/A
• Internal heat gains and occupancy level
Occupancy levels and miscellaneous loads for all conditioned rooms are listed below. Although
the lighting loads for different rooms are different, the variations are not huge (slightly higher or
lower than 1 W/ft2), thus the average value of 1 W/ft2 is used as the internal heat gain from lighting
systems for all rooms. Both sensible heat gains and latent heat gains from people for all area are
assumed as 275 Btu/h·person. The miscellaneous load varies differently based on the room type
and the equipment inside the rooms. The miscellaneous loads for all conditioned room are
indicated below. The sensible heat gain is assumed to be the same as the power of equipment inside
the room.

57

Table 3.4: Internal heat gains and occupancy level

Internal Heat Gains
Room Miscellaneous People Lighting
First Floor # of People
Sensible Heat
Gain
Sensible
Heat Gain
(Btu/h per
person)
Latent Heat
Gain (Btu/h
per person)
Heat
Gain
(W/ft2)
Studio-East 22 1 W/ft2 275 275 1
Studio-West 29 1 W/ft2 275 275 1
Center Bay 15 3000 Btu/h 275 275 1
Center Bay A 4 1200 Btu/h 275 275 1
Center Bay B 6 1800 Btu/h 275 275 1
Gallery 50 0 250 200 1
Shoot Room 5 6000 Btu/h 275 275 1
Shoot Room
Storage
2 1200 Btu/h 275 275 1
Laser Cutting 2 3120 Btu/h 275 275 1
3D Printer 2 2550 Btu/h 275 275 1
Shop Office 1 600 Btu/h 250 200 1
CNC Router 3 1200 Btu/h 275 275 1
Woodshop 20 1.5 W/ft2 275 275 1
Ceramics 20 1.5 W/ft2 275 275 1
TOTAL 181
Second Floor
Seminar 6 3600 Btu/h 275 275 1
Digital Lab 10 2100 Btu/h 250 250 1
Editing Bay 2 3000 Btu/h 250 250 1
Sound Studio 2 1200 Btu/h 275 275 1
Office 1 2 1200 Btu/h 250 200 1
Office 2 2 1200 Btu/h 250 200 1
Apartment 2 105 Btu/h 245 105 1
Print Lab 4 6000 Btu/h 275 275 1
TOTAL 30
BUILDING
TOTAL
211

58

• Building thermal zones & HVAC system of retrofit case 1

Figure 3.19: Thermal zones at the first floor

Figure 3.20: Thermal zones at the second floor

59

Rooms under the same HVAC systems are listed below.
Table 3.5: Rooms under the same thermal zones
PAC1 (Packaged Air Conditioner) Woodshop
PAC2 (Packaged Air Conditioner) Studio East
PAC3 (Packaged Air Conditioner) Studio West
PAC4 (Packaged Air Conditioner) Ceramics
VRF1 (Variable Refrigerant Flow) ShootRoom, Gallery, Centerbay, CenterbayA,
CenterbayB, Shoot Room Storage
VRF2 (Variable Refrigerant Flow) Seminar, Office1, Office2, Digital Lab, Print Lab,
Sound Studio, Office 2, Editing Bay
Split HP (Split Heat Pump) Apartment
Split AC 1 (Split Air Conditioner 1) Elev Machine Room
Split AC 2 (Split Air Conditioner 2) Telecom
DOAS (Dedicated Outside Air) Provides outside air ventilation for rooms under VRF
and Split HP and Split AC.
Retrofit options that are applicable for this building are listed below:
Table 3.6: Retrofit options for baseline model
Retrofit
Option
Category Building parameters
RO1 Building envelope Improved glazing thermal properties
RO2 Building envelope Redo the roof, improved insulation on Roof
RO3 Building envelope Added insulation on the existing exterior building walls
RO4 Building envelope Added insulation on the newly constructed building walls
RO5 HVAC systems Building HVAC system options
RO6 Lighting Improved lighting efficiency, replace the lighting fixture into
LED product
• Retrofit cases comparisons and general descriptions
The baseline model is constructed based on code requirements while the retrofit options in
retrofit case 1 are collected from architectural design firm and MEP design firm. The detailed
retrofit options for retrofit case 2 will be added based on the result of energy demand rankings
and cost rankings.

60

Table 3.7: Retrofit cases comparisons

Existing building Baseline Model Retrofit Case 1 Retrofit Case 2
HVAC system
No cooling, poor
ventilation control
Change HVAC
type, improve the
HVAC efficiency
to code requirement
Increase HVAC efficiency, no
system type change with
baseline model
TBD
Added Economizer TBD
Variable speed drive on all
fans (change constant air
volume to variable air volume
type of system)
TBD
Lighting
Inefficient
fluorescent lighting
Improved lighting
efficiency - code
requirement
LED light TBD
Add Dimming control and
other advanced controls
TBD
Add Daylight harvesting TBD
Envelope
External Wall: bare
concrete
Added renovated
external wall, no
insulation
Added interior furring to the
external wall, improved U
value
Added insulation in the
interior furring
Poor air tightness:
air leakage
same as baseline improved air tightness same as retrofit case 1
Redo the roof, meet
the code
requirement
Redo the roof, improve the
insulation
Redo the roof , added
better insulation
Glazing types, meet
the code
requirement
Improved glazing types TBD
3.3.2 Details of retrofit case 1:
Table 3.8: Details of retrofit case 1
Building Parameter Description Value
External Wall 1
(Existing Wall at studio
area)
Light Mass Wall: The existing 4”concrete of the studio
area is maintained for building renovation. Added furring
to the interior of existing building.
U value = 0.30
External Wall 2
(Addition Area)

Heavy Mass Wall: New Tilt Up concrete wall of the
addition area. (140 𝑙𝑏 /𝑓𝑡
3
). Added gypsum board and
plywood in the interior
Thickness = 10 inch.
U value = 0.2434
Ground Floor Concrete Slab on Grade: the existing slab is elevated
from the adjacent grade.
U value = 0.003
Interior Floor Interior Floor/Ceiling U value: 0.188
Barrel Roof Improved insulation on the roof U value: 0.034
Barrel Roof (New) Improved insulation on the roof U value: 0.034
61

Solar reflectance:0.1
Thermal Emittance:0.75
SRI: 16
Skylight Unit Skylight above the studio: Glass, Curb Mounted
Structural Skylight above the additional area
U value= 0.46
SHGC=0.3
VT = 49%
Exterior Window Fixed Window U value= 0.36
SHGC=0.4
VT=42%
Interior Wall/ Internal
Partition
Interior Wall and demising wall. Demising wall: wall
separates conditioned space with unconditional space.
U value: 0.37
Lighting Traditional fluorescent lighting (Control On/Off)
Added dimming light and daylight harvesting
Averaged Lighting Load: 0.7 W/𝑓𝑡
2

Packaged Air
Conditioner 1 & 4
Fully Air Conditioner: Packaged Air Conditioner with
Constant Air Volume (DX cooling with gas furnace
heating). Improved the cooling efficiency. Located in
Studio Area:
135000 Btu/h≥ Size ≥ 65000 Btu/h
EER = 12.1
IEER = 18.1
E
𝑡 = 80%
Fan efficiency = 70%
Motor Efficiency = 90%
Packaged Air
Conditioner 2
Located in Studio Area, improved cooling efficiency
Size ≥ 240000 Btu/h
EER = 11.09
IEER = 17.93
E
𝑡 = 80%
Fan efficiency = 70%
Motor Efficiency = 90%
Packaged Condition3 Located in Studio Area, improved cooling efficiency
240000 ≥ Size ≥ 135000 Btu/h
EER = 11.64
IEER = 11.64
E
𝑡 = 80%
Fan efficiency = 70%
Motor Efficiency = 90%
Dedicated Outside Air
System
Provide outside air for rooms which need extra outside
air for ventilation,
EER: 12.8
E
𝑡 = 80%
Variable refrigerant
volume 1
Electrically Operated VRF multi-split system air to air
heat pump. Heating and cooling system.
Size ≥ 135000 Btu/h
EER = 13.9
IEER = N/A
COP = 4
62

Variable refrigerant
flow 2
Electrically Operated VRF multi-split system air to air
heat pump. Heating and cooling system.
240000 ≥ Size ≥ 135000 Btu/h
EER = 15.1
IEER = N/A
COP = 4.3
Split Heat Pump Heating only EER = 9.1
COP = 3.5
Split Air Conditioner
1&2
Provide heating and cooling Split AC 1
EER = 9.1
COP = 3.5
Split AC 2
EER = 12.5
COP = 3.7
Boiler (DHW) Domestic hot water boiler Efficiency = 80%

3.4 IES VE model set up and process
3.4.1 Introduction
There are three steps involved to build a model and run the simulation in IES VE: which are
building the model in the ModelIT, running the thermal/load calculation in Apache and running
the detailed system simulation in ApacheHVAC. One of the characteristics of IES VE is that the
simulation process could be very complex due to the very detailed input for setting up HVAC
system. The details for each step and the assumptions made for building the model are defined
below.

Figure 3.21: IES VE procedures

63

3.4.2 ModelIT
The ModelIT is a 3D interface for modelling and assigning materials to the building envelope. The
architectural drawings and floor plans for the baseline building are collected from the architectural
design firm. The 3D Rhino model and 2D architectural drawings are used to construct the 3D
model in IES VE. This simple building involves 109 rooms and 8 thermal zones. There are some
simplifications made for the model, for example, the barrel roof is not able to be modelled in the
IES VE at the moment, instead, it is modelled as sloping roof.

Figure 3.22: 2D and 3D model in IES VE
The building envelope could either be constructed by building layers which matches with the
drawings or by selecting the building construction from the construction library in IES VE which
has similar U value with the construction type required by architects. The input of building
materials could be changed in order to test the sensitivity of thermal properties input on the energy
demand. Every single building surface could be easily selected in the assign construction interface
and the thermal properties could be changed.
64

Figure 3.23: Project construction interface 1 in IES VE- Detailed layers of external wall

Figure 3.24: Project construction interface 2 in IES VE– Summary

65

3.4.3 Apachesim
• Internal heat gains
The internal heat gains of each room from people, lighting and miscellaneous could all be defined
in the building template manager. The rooms with the same internal heat gains could use the same
room template.

Figure 3.25: Internal heat gains for each room in IES VE

Figure 3.26: Building template manager in IES VE
66

• Daily Profile & Weekly Profile & Yearly Profile
The daily, weekly and yearly profile for each room type could be edited under the APpro Profiles
Database. The details of the occupancy weekly profiles for weekdays are indicated below. The
weekly profile consists of daily profile of each day in a week. Under the daily profile, the
percentage of occupancy occurrence over the maximum occupancy could be edited based on the
assumptions or the observations on occupancy behaviors of existing building.

Figure 3.27: Occupancy weekly profile in IES VE

Figure 3.28: Details of the occupancy occurrence on weekday

67

3.4.4 ApacheHVAC
There are generally four steps involved in the ApacheHVAC part. Firstly, the HVAC system types
need to be defined and system configurations could be built based on the
ventilation/heating/cooling requirement and system parameters. The HVAC autosize function
enables the automatic calculation of heating and cooling load and also the heating and cooling
capacity of the HVAC system as well as the ventilation rate of each room. The calculated result of
the HVAC system parameters could be incorporated with the information from apache and
modelIT to generate total energy consumption report.

Figure 3.29: Method diagram of HVAC system set up
Thermal zones: There are 8 thermal zones involved for this project. Each block below represents
one thermal zone.

Figure 3.30: Apache HVAC interface in IES VE

68

Rooms under the same system are grouped together and assigned under the same system.

Figure 3.31: Rooms under the same type of HVAC system
• Details of packaged air conditioner (PAC)
Each component of HVAC system could be edited based on the system types. The details of PAC
system are shown below. The layout of the system is constructed based on cut sheet of the
Packaged air conditioner obtained from vendor.

Figure 3.32: Details of package air conditioner (PAC) in IES VE
69

By the set-point for the HVAC system of PAC system, it is shown that the temperature of rooms
under PAC 1 is controlled between 70 °F and 75 °F during the day time, and the temperature of
the rooms are controlled between 60 °F and 80 °F.

Figure 3.33: Setpoints of HVAC system in IES VE
The outside air ventilation rate is defined as 15 cfm/person and 0.23 cfm/ft2. ApacheHVAC will
output the maximum ventilation flow rate based on the outside air ventilation requirement.

Figure 3.34: Outdoor air ventilation of HVAC system in IES VE
• Autosizing
The ApacheHVAC could auto-size the HVAC system based on the input related to thermal
properties of the buildings envelope (Apache thermal calculation), input of ventilation requirement
and control logics. These system parameters will then be combined with the other input from
ModelIT and Apache to calculate the energy consumption of the whole building.

Figure 3.35: System parameters output in IES VE 1: cooling and heat load
70

Figure 3.36: System parameters output in IES VE 2: ventilation flow rate
Expected output from the IES VE simulations:
All the data could also be extracted and exported into excel for further analysis.

Figure 3.37: Monthly energy usage from each end use in IES VE

Figure 3.38: Yearly end use pie chart in IES VE

71

3.4.5 Energy ranking model
In order to select the most energy efficient retrofit options, it is important to know the energy
savings capabilities of retrofit options. An energy demand ranking model which is based on the
theory of local sensitivity model will be used to provide energy savings capability rankings for
each retrofit input. The details of this ranking model are illustrated below.
Local sensitivity model was first used by Firth (2010) to investigate the uncertainties of model
inputs on the dwelling’s predicted CO2 emissions and then it was used as energy ranking model
for selecting single retrofit option for retrofit case studies on Swedish residential buildings. (Qian
Wang, 2014)
Retrofit energy ranking model:
𝐸𝑛𝑒𝑟𝑔𝑦 𝑅𝑎𝑛𝑘𝑖𝑛𝑔 𝑖 =
𝑑𝑦 𝑥 𝑖 𝑑𝑥 𝑖 𝑦
𝑑𝑦 𝑑𝑥 𝑖 ≈
𝑦 𝑖 (𝑥 𝑖 + 𝛥 𝑥 𝑖 ) − 𝑦 𝑖 (𝑥 𝑖 − 𝛥 𝑥 𝑖 )
2∆𝑥 𝑖
𝑥 𝑖 : input value of the retrofit parameter
y: energy demand of the baseline model
∆𝑥 𝑖 : the small change of input value 𝑥 𝑖
𝑑𝑦
𝑑𝑥
𝑖 : the change of energy demand resulted from the change of 𝑥 𝑖
𝑦 𝑖 (𝑥 𝑖 + 𝛥 𝑥 𝑖 ): the output value of the retrofit option when input is increased by 𝛥 𝑥 𝑖
𝑦 𝑖 (𝑥 𝑖 − 𝛥 𝑥 𝑖 ): the output of the retrofit option when input is decreased by 𝛥 𝑥 𝑖

There are several steps involved to calculate the sensitivity/energy savings capability of each
retrofit option. Step 1: Define the maximum, minimum input value of each retrofit option i and
intervals ∆𝑥 𝑖 .
Step 2: Use the energy simulation tool to calculate the change of y with the increase ∆𝑥 𝑖 of input
value from minimum input value to maximum input value.
Step 3: Compare the sensitivity level between different retrofit options and rank the energy savings
capabilities of selected retrofit options.

72

3.5 Lifecycle cost analysis, energy savings cost and LCC savings
3.5.1 LCCA boundary
For this research, the ECM investment cost, repair and maintenance cost, operational cost
including maintenance cost will be analyzed in this research. 15 years and 30 years are chosen as
the time period for conducting the lifecycle cost analysis. It is assumed this building will not be
demolished within the studied time period.
LCC = ECM + RMC + OC
3.5.2 LCCA economic factors
Table 3.9: LCCA economic factors
Utility Cost Values Source
Electricity Cost in 2016 0.149 dollars/kWh CPUC (2016)
Natural Gas Cost in 2016 1 dollar/therm USDL(2017)
Real Discount Rate in United
States (d)
3% FEMP (2017)
Nominal discount rate 2.4% FEMP (2017)
Implied long-term inflation rate -0.6% FEMP (2017)

3.5.3 ECM investment cost
The investment cost of energy conservation measures will be collected for this research and the
details of the cost for all ECMs are presented in chapter 4. The source of the cost for all ECMs are
collected from RS Means (2017) and cost estimation report for retrofit case 1, which is produced
by local cost estimation firms.
3.5.4 Repair and maintenance cost
The repair and maintenance cost consists of non-annual recurring costs such as repair and
replacement and annually recurring cost such as routine maintenance cost. The single present value
will be used to calculate the non-annually recurring cost and uniform present value (UPV) will be
used for calculating the routine maintenance cost. The escalation cost and equipment price
fluctuations are not considered for this thesis.

73

The single present value (SPV) factors introduced by national institute of standards and technology
will be used for calculating the repair and replacement costs for this thesis. The present value (P)
of the repair and replacement cost is calculated using the following equation (Priya D. Lavappa,
2017):

How to use the single present value:
To calculate the net present value of replacement cost for air-cooled condensers in 20
th
year, the
SPV at the 20
th
year (0.554) from Table A-1 will be multiplied with the equipment cost at the base
year (2017).

Table 3.10: SPV factors for future single costs (Priya D. Lavappa, 2017):
74

The replacement periods of lighting fixtures and HVAC equipment are dependent on their life
span. The life expectancy of HVAC system equipment is provided below. (ASHRAE, 2017)

Table 3.11: Life expectancy of HVAC components (ASHREA, 2017)
The routine maintenance cost will be calculated using the uniform present value. A is the routine
maintenance cost. The annually recurring costs of the commercial building over 10 years will be
calculated using the UPV value at the 10
th
year (Priya D. Lavappa, 2017) and UPV value is then
multiplied with annually recurring cost at the base year (2017).

75

Table 3.12: UPV factors for annually recurring uniform costs (Priya D. Lavappa, 2017)

3.5.5 Operational cost
Energy cost is included for the operational cost. There are several economic factors which need to
be taken into consideration for calculating the energy cost, such as the escalation and inflation rate
of energy cost. The UPV Calculation Method was provided by National Institute of Standards and
Technology (Priya D. Lavappa, 2017) to predict the future energy cost in present value to assist
lifecycle cost analysis, this method incorporated the escalation rate and inflation rate of future
energy cost computed by Energy information administration (EIA) of the US Department of
Energy from 2013 and 2043. It is assumed that the annual energy consumption of the UCLA
graduate art studios does not change during the studied time period, thus this method could be
applied for the energy cost prediction.
76

How to use UPV* factors:
To calculate the electricity usage of a commercial building in California over the 25 years, the
UPV factor found in the following table (17.57) needs to be multiplied with the annual energy cost
of the base year. For this thesis, 2017 is the base year, so the electricity cost over the 25 years equal
the annual electricity cost of 2017 multiply with 17.57.

Table 3.13: UPV factors for fuel price escalation (Priya D. Lavappa, 2017)

The escalation rates of future energy cost are already incorporated into the operational cost. The
details of the energy cost changes were predicted by the Energy Information Administration in
United States. The details of electricity and natural gas cost predictions are presented below. (EIA,
2015)
77

Figure 3.39: Natural gas prediction by EIA (2015)

Figure 3.40: Electricity prediction by EIA (2015)

78

3.5.6 Cost-effectiveness model
To compare the cost savings capability of a single retrofit option in a long-term perspective, the
cost rankings equation was introduced in this thesis. Different than the research of Qian Wang
(2016), the baseline model used in this research is modified and it is different from the existing
building. The cost related to HVAC improvement in the baseline model will be considered as the
investment cost for baseline model. Thus, investment cost in the cost ranking equation is replaced
by investment cost difference between baseline model and retrofit case model.
𝐶𝑜𝑠𝑡 𝑅𝑎𝑛𝑘𝑖𝑛𝑔𝑠 𝑖 =
𝐸𝐶𝑀 𝑖 − 𝐸𝐶𝑀 𝑏𝑎𝑠𝑒𝑙𝑖𝑛𝑒 𝑂𝐶
𝑠𝑎𝑣𝑖𝑛𝑔𝑠 ,𝑖 + 𝑅𝑀𝐶 𝑠𝑎𝑣𝑖𝑛𝑔 ,𝑖 𝑝
𝑂𝐶
𝑠𝑎𝑣𝑖𝑛𝑔𝑠 ,𝑖 = 𝑂𝐶
𝑖 − 𝑂𝐶
𝑏 𝑎 𝑠𝑒𝑙𝑖𝑛𝑒
𝑅𝑀𝐶 𝑠𝑎𝑣𝑖𝑛𝑔𝑠 ,𝑖 = 𝑅𝑀𝐶 𝑖 − 𝑅𝑀𝐶 𝑏𝑎𝑠𝑒𝑙𝑖𝑛𝑒
Expected result:
1. Using the energy ranking model and cost rankings model to provide the optimum retrofit
option and retrofit packages
2. Incorporate the optimum retrofit option and retrofit packages to retrofit case 2
3. Conducting lifecycle cost analysis for the baseline model, retrofit case 1 and retrofit case
2. Compare the ECM cost and lifecycle cost for different retrofit cases in 15years and 30
years
4. Compare the baseline model and retrofit case 1, evaluate the effectives of energy ranking
model and cost ranking model.

79

4. Data collection and results
4.1 Research problem
Selecting building retrofit options for a building energy retrofit project with energy efficiency
goals is a multi-objective optimization problem with many parameters and it is difficult for
building designers to evaluate the energy efficiency and cost saving potential of the complete range
of potential ECM combinations. This thesis tends to generate tools to assist designers/engineers to
select the optimum building retrofit option/retrofit packages in terms of energy efficiency and
potential long-term cost savings. Different retrofit options of the studied building (UCLA Graduate
Art Studios) are collected as well as their cost information. The energy simulation software IES
VE is used for estimating the energy saving potentials of single retrofit option and retrofit plans
(baseline model and retrofit case 1) while lifecycle cost analysis is adopted to evaluate the long-
term (15 years and 30 years lifetime) cost saving capabilities of single retrofit option and retrofit
plans. Retrofit options or packages with higher energy savings and higher long-term cost saving
potentials are used to improve the baseline model. The energy simulation result and lifecycle cost
estimations result for all retrofit options and retrofit plans are also presented in this chapter.
4.2 Single retrofit option descriptions and cost information collections
Detailed descriptions and cost information about the retrofit options used for simulations are
illustrated in the following section. There are six types of retrofit options, which are skylight
retrofit with different glazing types (RO1: retrofit option 1), roof retrofit with improved insulation
(RO2: retrofit option 2), existing exterior wall retrofit with improved insulation (RO3: retrofit
option 3), new exterior wall retrofit with improved insulation (RO4: retrofit option 4) , HVAC
retrofit (RO5: retrofit option 5) and lighting retrofit (RO6: retrofit option 6). Cost information is
collected and summarized from varies sources, including RS Means, vendors and manufacturers.
Cost models are developed based on the cost information in RS Means to predict HVAC equipment
with different sizes.
4.2.1 Introduction
The retrofit options are selected based on the code requirements, building evaluations, as well as
the availability of the product in the market. The cost information collection and estimation
procedures are far more complex and time consuming than expected because of the lack of
consistent cost information in the market, for example, variations of building equipment cost from
different vendors and manufacturers. To have more unbiased comparisons, RS Means was used as
the cost estimation database for collecting cost information. There are also constraints of using RS
Means as a single cost information resource, for example, pricing of building envelope and glazing
materials with different thermal properties are not provided in RS Means. Thus, cost information
from manufactures and vendors is used as supplemental resources for cost estimations. The life
expectancy of building envelope components is collected from National Association of Home
Builders Economics Department (NAHBED,2017) while the life expectancy of HVAC systems
and lighting system is collected from ASHRAE equipment life expectancy chart (ASHRAE, 2017)
and Life cycle costing for design professional (Stephen J.Kirk, 1995) respectively. Several
assumptions are made for retrofit cost estimations and the details for each retrofit information are
listed below.
80

4.2.2 Building envelope – glazing options
It is assumed that the same type of glazing is used for both structural skylight and unit skylight.
The glass information with different thermal properties is not available in RS Means, thus, it was
mainly collected from a company called Wasco Skylights (2018). The thermal properties of each
different skylight and descriptions are provided below. The labor cost for installation is included
for the investment cost and the rooftop skylight area is 4488 𝑓𝑡 2
. The glazing types listed below
are either double glazing or triple glazing. It was stated by N.P Howard (2007) that the double-
glazing system could have 35 years of life time while the life expectancy of double glazing system
is estimated between 30 and 35 years according to international standards for lifetime forecasting.
Thus, in this research, it is assumed that all the glazing systems including double glazing and triple
glazing has 30 years life expectancy. According to the cost method described in chapter 3, the
replacement cost of glazing in the 30
th
year is calculated through multiplying the SPV factor (0.412)
in 30
th
year with main investment cost in the base year 2017. Framing is not included for the cost
estimations and the investment cost of glazing option for the baseline model is estimated using the
cost information from RS Means. All the glazing options were represented as RO1. There are six
types of glazing options, RO 1.1, RO1.2, RO1,3, RO1.4, RO1.5, RO1.6, the glazing option
followed with higher number has higher U value and solar heat coefficient varies with different
glazing options.

81

Table 4.1: Descriptions and details of glazing retrofit options
Descriptions and details of glazing retrofit options
Glazing Type Layers Descriptions
Baseline N/A Double Glazing Unit
RO1.1

Hurricane resistant glazing for
coastal applications
RO1.2

Double glazing and energy
efficient glazing system, high
performance low-E insulated
glass with argon.
RO1.3

Double glazing and energy
efficient glazing system, high
performance low-E insulated
glass with argon.
RO1.4

Triple glazing and provides
better insulation value than
double glazing
RO1.5

Double glazing and
electronically tintable,
sunlight could be controlled
without shades and blinds
(VLT should be changed)
RO1.6

Highest daylight control
product in the market, good
thermal insulator and
environmentally sound

82

Table 4.2: Thermal properties of glazing retrofit options
Thermal properties of glazing retrofit options
Glazing
options
Name VLT U Factor SHGC Resource
RO1.0 Baseline 49% 0.58 0.25 (CEC, 2016)
RO1.1 HR 57% 0.5 0.25 (Wascoskylight,2018)
RO1.2 EMT 60% 0.49 0.27 (Wascoskylight,2018)
RO1.3 EML 59% 0.48 0.27 (Wascoskylight,2018)
RO1.4 TGT
(Retrofit
Case1)
46% 0.33 0.23 (Wascoskylight,2018)
RO1.5 SGU 60% 0.28 0.41 (Wascoskylight,2018)
RO1.6 LA 38% 0.19 0.31 (Wascoskylight,2018)
Table 4.3: cost Information of glazing retrofit options
Cost Information of glazing retrofit options
Glazing
Options
Cost/ft2 Investment
Cost
Maintenance
Cost (per
year)
Replacement
Cost (in 30
th

year)
Life
expectancy
(year) (N.P
Howard,
2007)
RO1.0 109 489192 N/A 201547 30
RO1.1 163.26 732710 N/A 301877 30
RO1.2 110.51 495968 N/A 204339 30
RO1.3 119.89 538066 N/A 221683 30
RO1.4 131.86 591787 N/A 243817 30
RO1.5 172.64 774808 N/A 319221 30
RO1.6 138.02 619433 N/A 255207 30

4.2.3 Building envelope – roof options
The U value of the roof is changed through the change of insulation thickness. 20 PSI Energy
Guard Polysio Insulation (GAF, 2018) is used for roof insulation and the details for roof retrofit
information are listed below. The cost information is collected from both RS Means (2017) and
two cost reports provided by local cost estimation firms: C.P O’ Halloran associates Inc and the
Capital Projects group. There was little information available for maintenance costs of government
and private sectors, which adds to the difficulty of maintenance cost estimation for this thesis. The
maintenance cost is the most difficult part to determine because the life expectancy of building
equipment would be extended due to regular and proper repair, also, its life expectancy would be
dramatically decreased due to improper management. The annual averaged maintenance cost for
roofing systems in the market varies between 0.05 dollar/ft2 band 0.25 dollars/ft2 based on roofing
materials and maintenance frequency. Due to the lack of building maintenance data of the studied
building, the annual maintenance cost for the roof is assumed to be 1% to 2% of the roofing system
cost and the annual averages maintenance cost of roof is between 0.27 and 0.3354 dollars/ft2,
which is slightly higher than the market standard price. It is assumed that the building roof does
not need major replacement if certain frequency of maintenance is maintained.
83

Figure 4.1: Roof section view of retrofit case 1
Table 4.4: The baseline roof and its roofing thermal properties
The Baseline roof and its roofing thermal properties
Roofing
Materials
Thickness Conductivity
(Btu.in/h.ft2.F)
U value
(Btu/h.ft2.F)
Existing
Roof Area
(m2)
New Roof
Area (m2)
Plywood
Sheathing
15/32” 0.808

0.82

20874

14645
20 PSI Rigid
Insulation
1.8” 0.175
Roof Cover
Board/Gypsum
Board
0.5” 1.125
Roof Membrane N/A N/A
Table 4.5: Thermal properties of roof options
Thermal properties of roof options
Roof options Insulation
Thickness
(inch)
Insulation
R value
Roof
Assemblies
U factor
Solar
Reflectance/Solar
Emittance
Resources
RO2.0
(Baseline)
1.8 10.2 0.082 0.1/0.75 (GFA,2018)
RO2.1 2.8 16 0.0562 0.1/0.75 (GFA,2018)
RO2.2 3.8 21.7 0.0425 0.1/0.75 (GFA,2018)
RO2.3 4.8 27.4 0.034 0.1/0.75 (GFA,2018)

84

Table 4.6: Cost information of roofing system
Cost information of roofing system
Name Investment
Cost/ft2
Maintenance
Cost (per
year)
1.5% of the
investment
cost
Replacement
Cost
Life Expectancy
(NAHBED,2017)
Plywood
Sheathing over
the existing
roof structure
3.72 0.0558 N/A
>30
Roof Cover
Board/Gypsum
Board
2.63 0.03945 N/A >30
Roof
Membrane
8.96 0.1344 N/A >30
Caulking and
sealants
0.36 0.0054 N/A >30
1.8 inch 20
PSI Rigid
Insulation
2.68 0.0402 N/A >30
2.8 inch 20
PSI Rigid
Insulation
4.01 0.06015 N/A >30
3.8 inch 20
PSI
Rigid
Insulation
5.3582 0.080373 N/A >30
4.8 inch 20
PSI Rigid
Insulation
6.6972 0.100458 N/A >30
New Roof structure cost/ft2 103

85

Table 4.7: Cost information of existing roof structure
Cost information of existing roof structure
Existing Roof Structure Unit Unit Cost Total Cost Life
Expectancy

Steel framing below
bowstring truss lower chord
18 TNS 5610 100980

>30
Remove and replace diagonal
brace with new steel angle
6 TNS 6171 37026
Anchor bolts. Hilti KB-TZ
5/8” diameter with 3/8”
embed
148 EA 44.68 6612
Total Existing Roof Structure
Cost
144618
Existing Roof structure
cost/ft2
6.9
New Roof Structure Unit Unit Cost Total Cost Life
Expectancy
Steel framing 289 CY 842.52 454410

>30
Reinforced concrete beams 81 TNS 5610 243488
Wall anchors at 4’oc 289 CY 842.52 35006
Steel tie rod, 1” diameter 1492 LF 67.32 100441
Wood beams, glumlam
curved, 81/2” x 16 ½”
718 LF 190.40 136707
Wood beams, glulam curved,
6 ¾” x 12 3/8”
688 LF 107.10 73685
Wood purlins, glulam, 3 ½” x
11 7/8” @ 24” oc
14645 29.45 476335
Total New Roof Structure
Cost
1519872
New Roof structure cost/ft2 103

86

Table 4.8: Summary of roof cost
Summary of roof cost
Roofing
Investment
Cost/per
square feet
Roofing
Investment
Cost ($)
Maintenance
Cost
$/year/ft2
(1.5% of
roofing
investment
cost)
Replacement
Cost
Life
expectancy
RO2.0 18.35 651773.65 0.275 N/A >30
RO2.1 19.68 699013.92 0.2952 N/A >30
RO2.2 21.02 746900.63 0.3154 N/A >30
RO2.3 22.36 794460.57 0.3355 N/A >30
Structural Cost Summary
Existing
Roof
Structure
6.9 144618 N/A N/A >30
New Roof
Structure
103 1519872 N/A N/A >30
RO 2.0 RO 2.1 RO 2.1 RO 2.3 (Retrofit Case 1)
Existing
Roof
Investment
Cost ($)
2902846 2950086 2997682 3045277

4.2.4 Building envelope – exterior wall options
There are two types of wall assemblies in the UCLA Graduate Art Studios. The existing wall (1a)
of the studio area will be renovated while new wall assemblies will be built for the expansion area.
The details of the wall assemblies and retrofit options are indicated below.
• Existing wall (renovation area)
The existing building wall of the renovation area (studio) is 4” bare concrete. The proposed retrofit
options for renovating this type of wall is adding 1”x3” interior wood furring strips and adding
insulation into the furring space to increase the insulation. The effective R value of insulation
installed 1” furring space is collected from Table 4.3.14 of Title 24, Part 6 Reference Appendices.
(CEC, 2016) The cost information of different insulation information is collected from PG&E
Codes and Standards Enhancement Initiative. (PG&E, 2008)
87

Figure 4.2: Existing wall 1a (baseline) and existing wall 1b (retrofit case 1)
Table 4.9: Existing wall retrofit options
Existing wall retrofit options
Additional Wall
assemblies
Descriptions R value of
Insulation in the
furring space
（CEC,2016）
U value Life Expectancy
(NAHBED,2017)
RO3.0 (Baseline/1a) Bare concrete N/A 0.873 >30
RO3.1 (Retrofit Case
1/1b)
Added furring
strips
N/A 0.4288 >30
RO3.2 Added insulation
R2
2.2 0.2196 >30
RO3.3 Added insulation
R4
3.4 0.1744 >30
RO3.4 Added insulation
R6
4.3 0.1505 >30
RO3.5 Added insulation
R8
4.9 0.1382 >30

88

Table 4.10: Thermal properties of existing wall assemblies (retrofit case 1)
Thermal properties of existing wall assemblies (retrofit case 1)
Wall layers (1b) Thickness Conductivity
(Btu.in/h.ft2/F)

U value
Wall Area
4” Concrete (E) 4” 13.514

0.4288

4727
Wood framing –
interior furring
1” x 3” N/A
Plywood 1/2 ” 0.798
Gypsum board 5/8 ” 1.125

Table 4.11: Existing wall retrofit options
Existing wall retrofit options
Additional Wall
assemblies
Descriptions R value of
Insulation
in the
furring
space
U value Life Expectancy
(NAHBED,2017)
RO3.0 (Baseline/1a) Bare concrete N/A 0.873 >30
RO3.1 (Retrofit Case
1/1b)
Added furring strips N/A 0.4288 >30
RO3.2 Added insulation R2 2.2 0.2196 >30
RO3.3 Added insulation R4 3.4 0.1744 >30
RO3.4 Added insulation R6 4.3 0.1505 >30
RO3.5 Added insulation R8 4.9 0.1382 >30

Table 4.12: Cost information of existing wall retrofit options
Cost information of existing wall retrofit options
Wall assemblies Invest
ment
Cost/ft
2
Existing Wall
1b Total
Investment
Cost
Maintenance
Cost (per year,
per square feet)
Replaceme
nt Cost
Life
Expectancy
4” Concrete (Existing-
Seismic)
1.58 7468.66 N/A N/A 30-70
Wood framing 2”x4”
– interior furring
6.38 30158.26 N/A N/A 30-70
Plywood 3.72 17584.44 N/A N/A 30-70
Gypsum board,
painted
5.47 25856.69 N/A N/A 30-70
Insulation R2 0.43 2032.61 N/A N/A 30-70
Insulation R4 0.52 2458.04 N/A N/A 30-70
Insulation R6 0.62 2930.74 N/A N/A 30-70
Insulation R8 0.71 3356.17 N/A N/A 30-70
89

Existing Wall Options Invest
ment
Cost/ft
2
Total
Investment
Cost
Maintenance
information
Replaceme
nt Cost
Life
Expectancy
RO3.0 (Baseline/1a) 1.58 7468.6 N/A N/A 30-70
RO3.1 (Retrofit Case
1/1b)
17.15 81068.05 N/A N/A 30-70
RO3.2 17.58 83100.66 N/A N/A 30-70
RO3.3 17.67 83526.09 N/A N/A 30-70
RO3.4 17.77 83998.79 N/A N/A 30-70
RO3.5 17.86 84424.22 N/A N/A 30-70

Table 4.13: Cost information of insulation layers (PG & E, 2008)
Cost information of insulation layers
R-Value Material Cost
($/dollars)
Labor Cost ($/dollars) Total O&P Cost
($/dollars)
2 0.09 0.34 0.43
4 0.18 0.34 0.52
6 0.28 0.34 0.62
8 0.37 0.34 0.71
Wood stud framing
2”x6” interior
7.14 6.1 13.24
Wood stud framing
2”x4”
6.38 5.5 11.8
R-11 batt 0.385 0.42 0.93
R-13 batt 0.594 0.42 1.14
R-15 batt 0.7 0.42 1.25
R -19 batt 0.66 0.42 1.21
R -21 batt 0.8 0.42 1.35
Concrete 10” tilt up 62.73

• New Exterior Wall (Expansion area)
The new wall assembly of the baseline model is 10” bare concrete and proposed retrofit options
improve the thermal properties of 10” concrete wall by adding wood framing and adding insulation
between framing spaces. The framing system for 10” concrete wall is 2“x4” and 2”x6” framing
system. The U value of the different insulation assemblies is collected from draft report –
nonresidential opaque envelope (John, 2016) and the cost information is collected from Codes and
Standards Enhancement Initiative (PG & E, 2008).
90

Figure 4.3: Baseline Wall Assemblies (New Construction)

Figure 4.4: Retrofit Case 1 Wall assemblies (New Construction)
Table 4.14: Thermal properties of wall assemblies in retrofit case 1
Thermal properties of wall assemblies in retrofit case 1
Retrofit Case 1 Thickness Conductivity
(Btu.in/f.ft2.F)
U factor

Life expectancy
Concrete 10” 10” 13.514
0.3241
30 – 70
Plywood 3/4” 0.798 30 – 70
Gypsum Board 5/8” 1.125 30 – 70

Table 4.15: Thermal properties and cost information of new wall assemblies in retrofit case 1
Thermal properties and cost information of new wall assemblies in retrofit case 1
Additional
Wall
assemblies
Insulation
assembly
Insulation
assembly
U factor
Adjusted
U value
Investment
Cost ($ per
square
feet)
Investment
Cost
(dollars)

Life
Expectancy
RO4.0
(Baseline)
Bare
concrete
N/A 0.6289 62.73
1358404
30-70
RO4.1
(Retrofit
Case 1)
2 x 4, no
insulation
N/A 0.3241 72.92
1579066
30-70
91

RO4.2 2 x 4, R-11
batt
0.11 0.1023 75.46
1634069
30-70
RO4.3 2 x 4, R-13
batt
0.102 0.0956 75.67
1638616
30-70
RO4.4 2 x 4, R-15
batt
0.095 0.0887 75.78
1640998
30-70
RO4.5 2 x 4, R-19
batt
0.074 0.070 75.74
1640132
30-70
RO4.6 2 x 6, R-21
batt
0.069 0.0657 77.32
1674347
30-70

4.2.5 Building HVAC system options
There are three types of HVAC system selected for comparisons, which are Packaged constant air
volume system, packaged variable air volume system and combination of Packaged variable air
volume system and Variable Refrigerant Flow system. The cost information about the HVAC
equipment is collected from RS Means (2017) and cost models are developed to predict pricing of
packaged air conditioner and VRF outdoor/indoor unit with different sizes based on cost data from
RS Means (RS Means, 2017). Two cost estimation reports are used as a supplemental resource for
cost estimation of other HVAC equipment components such as refrigerant piping, ductwork. The
details related to cost information are indicated below.
Table 4.16: HVAC systems comparisons
HVAC systems comparisons
HVAC system Descriptions Investment Cost Maintenance
Cost
Life Expectancy
(ASHRAE,2017)
RO5.0 Baseline Constant Air
Volume
Depends on
equipment size
Varies with
different
components
Varies with
different
components
RO5.1 Variable air
volume Added
VSDs
Depend on
equipment size
Varies with
different
components
Varies with
different
components
RO5.2 Retrofit Case 1
(VAV +
VRF+DOSA)
Depend on
equipment size
Varies with
different
components
Varies with
different
components

92

Figure 4.5: HVAC system cost estimation diagram
• Cost model for packaged air conditioner
The cost information for a packaged air conditioner is collected from the RS Means (2017). RS
Means provides cost information for equipment with different cooling and heating capacities,
including labor cost and equipment cost. However, Table 4.17 shows that cost information
provided by RS Means is not complete, for example, cost information for units with 7 ton cooling,
8.5 ton cooling and 11 ton cooling is missing. Thus, a cost model is developed based on the cost
information in RS Means to provide predication and estimation for packaged air conditioner with
different sizes.
Table 4.17: Packaged air conditioner price in RS Means (2017)
Description
Daily
Output
Labor
Hours
Bare
Material
Bare
Labor Bare Total
Bare
O&P
Rooftop air conditioner, standard controls,
curb, economizer

single zone, electric cool, gas heat

3 ton cooling, 60 MBH heating 0.7 22.857 2800 1773.2 4573.2 5734.8
4 ton cooling, 95 MBH heating 0.61 26.403 3325 2046 5371 6719
5 ton cooling, 112 MBH heating 0.56 28.521 4375 2216.5 6591.5 8107.7
6 ton cooling, 140 MBH heating 0.52 30.769 5000 2387 7387 9055.5
7.5 ton cooling, 170 MBH heating 0.5 32.358 5825 2489.3 8314.3 10151
8.5 ton cooling, 170 MBH heating 0.46 34.783 7075 2693.9 9768.9 11832.9
10 ton cooling, 200 MBH heating 0.67 35.982 9150 2898.5 12048.4 14430.7
12.5 ton cooling,230 MBH heating 0.63 37.975 10400 3034.9 13434.9 16003.5
17.5 ton cooling, 330 MBH heating 0.52 45.889 13900 3682.8 17582.8 20858.3
20 ton cooling, 360 MBH heating 0.67 47.976 29500 3921.5 33421.5 38399.3
25 ton cooling, 450 MBH heating 0.56 57.554 32000 4705.8 36705.8 42292.8
30 ton cooling, 540 MBH heating 0.47 68.376 25700 5592.4 41292.4 47722.7
40 ton cooling, 675 MBH heating 0.35 91.168 43900 7467.9 51367.9 59418.9

93

Figure 4.6: Packaged air conditioner investment cost model
• Cost model for VRF outdoor condensing unit
VRF Outdoor Condensing Unit Cost Estimation Model is developed using the same method.
Table 4.18: VRF condensing unit cost 1 (RS Means, 2017)
Description
Daily
Output
Labor
Hours
Bare
Material
Bare
Labor
Bare
Total
Total
O&P
Air source heat pump, not including interconnecting
tubing

Air to air, split system, not including curbs, pads, fan
coil and ductwork

Outside condensing unit only, for fan coil see section
23, 82 19.10

2 ton cooling, 8.5 MBH heat @ 0 2 8 1650 620.62 2270.62 2734.34
5 ton cooling, 27 MBH heat @ 0 0.5 32 2675 2489.3 5164.3 6641.9
7.5 ton cooling, 33 MBH heat @ 0 0.45 35.556 3875 2762.1 6637.1 8376.1
10 ton cooling, 50 MBH heat @ 0 0.64 37.5 6275 3000.8 9275.8 11460.3
15 ton cooling, 64 MBH heat @ 0 0.5 48 8725 3853.3 12578.3 15372
20 ton cooling, 85 MBH heat @ 0 0.35 68.571 17900 5490.1 23390.1 27986.3
25 ton cooling, 119 MBH heat @ 0 0.25 96 21100 7706.6 28806.6 34794

y = -7.5635x
3
+ 334.39x
2
- 1995.9x + 9767.1
R² = 0.9947
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
Cost
Cooling Capacity (Ton)
Packaged air conditioner investment cost model
94

Table 4.19: VRF condensing unit cost 2 (RS Means, 2017)
VRF condensing unit cost (RS Means,
2017)
Cooling Capacity Total O&P
2 2734.24
5 6642.9
7.5 8376.1
10 11460
15 15372
20 27986
25 34794

Figure 4.7: VRF outdoor condensing unit cost model
• Cost model for VRF indoor unit
VRF indoor unit (fan coil unit) Cost Estimation Model is shown below.
Table 4.20: VRF indoor unit (fan coil unit) (RS Means, 2017)
Fan coil units
Daily
Output
Labor
Hours
Bare
Material
Bare
Labor
Bare
Total
Bare
O&P
Fan coil A.C. cabinet mounted, includes filters and controls
fan coil A.C cabinet mounted, includes filters and controls
fan coil A.C, cabinet mounted, chillded water, 1/2 ton cooling, includes
filters and controls 8 2 555 154.13 709.13 843.24
fan coil AC, cabinet mounted, chilled water, 1 ton cooling, includes
filters and controls 6 2.667 830 205.96 1035.96 1225.99
fan coil AC, cabinet mounted, chilled water, 1.5 ton cooling, includes
filters and controls 5.5 2.909 835 225.06 1060.06 1258.27
fan coil AC, cabinet mounted, chilled water, 2 ton cooling, includes
filters and controls 5.25 3.048 1200 235.97 1435.97 1679.64
fan coil AC, cabinet mounted, chilled water, 3 ton cooling, includes
filters and controls 4 4 1950 309.63 2259.63 2613.76
y = -0.1152x
3
+ 33.211x
2
+ 574.16x + 2067.3
R² = 0.9859
0
5000
10000
15000
20000
25000
30000
35000
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Total O&p ($)
Cooling Capacity (ton)
VRF outside condensing unit cost model
95

Figure 4.8: VRF indoor fan coil unit cost model
• Differences between CAV and VAV system
Both CAV and VAV air conditioner systems consist of packaged air conditioner (air handling unit),
supply and return fans, duct system and control units. The major difference is that the VAV system
has additional VAV boxes and variable speed drives. (Mefmet Azmi Aktacir, 2005)
• Cost of other HVAC equipment (Area based cost)
The cost information related to piping and insulation, air distribution, diffusers and controls are
regarded as area-based cost. This area-based cost information is collected from the cost reports
which was produced by a cost estimation firm. The detailed cost information is summarized below
and it is incorporated into cost estimation summary of HVAC retrofit options.

y = 289.14x
2
- 443.11x + 1350.6
R² = 0.9916
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
1 1.5 2 2.5 3
Price (dolalrds ）
Cooling Capacity (ton)
VRF indoor fan coil unit cost model
96

Table 4.21: CAV System and VAV system cost comparisons (Summarized from cost reports)
CAV System and VAV system cost comparisons (Summarized from cost reports)

CAV System VAV system
Cost ($/ft2 or unit
price)
System Price in Total

Unit Total Cost
PAC 1
Depends on unit
size
Depends on unit
size
Depends on unit size
PAC 2
Depend on unit
size
Depend on unit
size
Depends on unit size
PAC 3
Depend on unit
size
Depend on unit
size
Depends on unit size
PAC 4
Depend on unit
size
Depend on unit
size
Depends on unit size
VAV dampers (4 unit) 0 17604

Variable Speed Drive (4
unit)
0 27826 6956
Other cost 684941 684936 31.50
Piping and insulation 16652 16652 0.77
Refrigeration piping 11961 11961 0.55
Insulation 3227 3227 0.15
Valves and connections 1464 1464 0.07
Air distribution 374327 374323 17.21
Galvanized ductwork 279706 279706 12.85
Flexible ductwork
connections
16935 16935 0.77
Dampers, fire and smoke 16162 16158 0.74
Insulation 61523 61523 2.82
Diffusers 62139 62139 2.86
Controls 177456 177456 8.16
Sub-contractor 28924 28924 1.33
Testing and balancing 25444 25444 1.17

97

Table 4.22: VRF System cost information (collected from cost report)
VRF System cost information (collected from cost report)
VRF System
Outdoor Unit Cost Cost/ft2
VRF1 outdoor unit
Depends on the unit
size

VRF2 outdoor unit
Depends on the unit
size

Dedicated outside air system 18448
Indoor Unit
Indoor fan coil units
Depends on the unit
size

Total Cost 264694.24
Refrigerant Piping and other equipment 37500 5.47
Refrigerant Piping, insulated between condensing unit
& indoor unit
37500
Air distribution 117924.96 17.21
Galvanized ductwork 88116.41 12.86
Flexible ductwork connections 5335.04 0.78
Dampers 5091.67 0.74
Insulation 19381.84 2.83
Diffusers 19575.63 2.86
DDC Controls 55904.16 8.16
Sub-contractor 9111.83 1.33
Testing and Balancing 8015.67 1.17
Other Cost 16662
Misc VRF system equipment 5200
Branch Selector Box (2) 11462

98

• Summary for different HVAC Retrofit Options
Table 4.23: Area for different HVAC retrofit options
Area for different HVAC retrofit options
RO5.0 RO5.1 RO5.2
System Type CAV system VAV system VAV + VRF system
Total Area 28589 28589 28589
CAV Area 28589 0 6851
VAV Area 0 28589 0
VRF System 0 21747
Table 4.24: Investment cost comparisons of HVAC retrofit options
Investment cost comparisons of HVAC retrofit options
Equipment cost
CAV
system
VAV system VAV + VRF system
Total Cost 1067843.36 1135987.07 1204202
Equipment Investment
cost
142860.64 142860.64 157306
PAC1 15684 15684 15684
PAC2 46258 46258 46258
PAC3 35316 35316 35316
PAC4 13376 13376 13376
PAC5/VRF1 11328 11328 10420
PAC6/VRF2 20899 20899 17764
DOSA Outdoor Unit
(2500cfm)
0 0 18488
VAV additional cost 0 68143.71 45429
VAV dampers (6 unit / 4
unit) )
0 26405.31 17604
Variable Speed Driver (6
unit/4 unit)
0 41738.4 27826
Duct, Piping, Sensors
Cost
900718.72 900718.72 932972.7979
99

Other cost/per ft2
(VAV/VRF)
31.50 31.50 31.50 36.20
Conditioned Area (ft2) 28598 28598 21747 6851
VRF System (Additional
cost)
0 0 44230.47
Indoor Unit Costs 0 0 27568.47
Other equipment (Misc
equipment & branch box)
0 0 16662
Other HVAC Equipment 24264 24264 24264
Split Air Conditioner (2) 14238 14238 14238
Split Heat Pump System 10026 10026 10026

Figure 4.9: Investment cost comparisons of HVAC retrofit options

142860.6412 142860.6412
201536.1726
0
68143.708
45429.13867
900718.7176
900718.7176
932972.7979
0
200000
400000
600000
800000
1000000
1200000
1400000
CAV VAV VAV+VRF
Investment Cost($)
HVAC Retrofit Options
Investment cost comparisons of HVAC retrofit options
Equipment Investment cost VAV additional cost Duct, Piping, Sensors Cost
100

• HVAC maintenance cost estimation: Life expectancy of different equipment
Table 4.25: Life expectancy of HVAC equipment
Life expectancy of HVAC equipment
Equipment Items Life Expectancy
Median Years
Annual Maintenance % of
investment cost
Air Conditioner
Rooftop Packaged Air Conditioner 15 7%
Dedicated Outside Air System 15 7%
Heat Pumps & VRF Outdoor Condensing
Unit

Commercial Air to Air 15 7%
Air Terminals
VAV and double-duct boxes 20 1%
Diffusers, Girlles and registers 27 1%
Induction and fan coil units 20 3%
Ductwork 30 1%
Dampers 20 7%
Controls
Electric/Electronic 15 1%
Other HVAC components (Assumed) 15 1%
Table 4.26: Annual maintenance cost comparisons of HVAC retrofit options
Annual maintenance cost comparisons of HVAC retrofit options

CAV VAV VAV + VRF
Air Conditioner & VRF outdoor
unit
10000.24 10000.24 11011.40
VAV dampers/Variable speed drive 0.00 681.44 454.29
VRF Indoor Unit Cost 0.00 0.00 1326.91
Other Equipment
242.64 242.64 242.64
Other Cost

Refrigeration piping and valves 218.98 218.98 541.52
Galvanized ductwork 3678.23 3678.23 3678.23
Flexible ductwork connections 222.70 222.70 222.70
Dampers, fire and smoke 1487.78 1487.78 1487.78
Duct Insulation 809.05 809.05 809.05
Diffusers 817.14 817.14 817.14
Controls 2333.60 2333.60 2333.60
Total Annual Maintenance Cost 19810.36 20491.80 22925.27

101

Table 4.27: 15 years maintenance and replacement cost comparison of HVAC options
15 years maintenance and replacement cost comparisons of HVAC retrofit options

CAV VAV VRF+VAV
Air Conditioner & VRF outdoor
unit 211119.45 211119.45 232466.36
VAV dampers/Variable speed
drive 0 8136.35 5424.23
VRF Indoor Unit Cost 0 0 15843.35
Other Equipment 18474.61 18474.60 18474.60
Other Cost

Refrigeration piping and valves 16673.09 16673.09 41231.35
Galvanized ductwork 43918.02 43918.02 43918.02
Flexible ductwork connections 2659.03 2659.03 2659.03
Dampers, fire and smoke 17764.13 17764.13 17764.13
Duct Insulation 61601.25 61601.25 61601.25
Diffusers 9756.67 9756.67 9756.67
Controls 177680.0 177680.06 177680.06
15 Year Maintenance Cost 559646.33 567782.69 626819.09

Table 4.28: 30 years maintenance and replacement cost comparisons of HVAC options
30 years maintenance and replacement cost comparison of HVAC retrofit options

CAV VAV VRF+VAV
Equipment Investment Cost 346579.91 346579.91 381466.32
VAV dampers/Variable speed drive 0 51107.781 34071.854
VRF Indoor Unit Cost 0 0 50511.19
Other Equipment 30330 30330 30330
Refrigeration piping 27372.42 27372.42 67690.0298
Galvanized ductwork 223636.19 223636.19 223636.19
Flexible ductwork connections 13540.12 13540.12 13540.12
Dampers, fire and smoke 37917.21 40935.29 40935.29
Duct insulation 101131.55 101131.55 101131.55
Diffusers 52787.35 52787.35 52787.35
Controls 291699.6 291699.6 291699.6
30 years maintenance cost 1124994.39 1179120.24 1287799.53

102

4.2.6 Lighting system retrofit options
• General lighting information
In order to evaluate the existing building lighting system, onsite visits were conducted to
investigate the lighting layout. The averaged lighting power density of the existing building is 1
Watts/square feet based on calculations, which meets the maximum lighting power density of the
Title 24 energy code requirement. The lighting power density of the retrofit case 1 is calculated
based on the lighting plan provided by the architecture firm. The detailed information is provided
below.
Table 4.29: Lighting retrofit options
Lighting retrofit options
Descriptions Lighting
power
density
(W/ft2)
Cost ($/ft2) Averaged Cost
Per lighting
fixture
Annual
Maintenance
of the
investment
cost
Life
Expectancy
RO 6.1 Baseline:
fluorescent lighting
1 2.94 108 3% 10000
hours
RO 6.2 Retrofit Case 1:
LED Lighting
0.485 19.28 750 0 50000
hours
• Lighting Maintenance Cost
Table 4.30: Annual maintenance cost comparisons of lighting retrofit options
Annual maintenance cost comparisons of lighting retrofit options
Investment Cost 15 Year
Maintenance Cost
30 Year
Maintenance Cost
RO 6.1 134972.46 559646.3367 1124994
RO 6.2 885125.52 525115.26 1068307

4.3 Energy savings of each individual retrofit option
The energy use intensity of all single retrofit options is listed below. Table 4.31 and Figure 4.11
shows that the RO3.5 has the higher energy savings capabilities while RO1.1 has the lowest energy
savings capabilities. The descriptions of all retrofit options are shown below.

103

Table 4.31: Summary of EUI Improvement on single retrofit options
Summary of EUI Improvement on single retrofit options

Retrofit Option

Retrofit Descriptions
EUI (kBtu/ft2)
EUI
Improved
(kBtu/ft2)
RO1.0
(Baseline)
U=0.58; VLT= 0.49; SHGC = 025
29.72
0%
Glazing

RO1.1 U=0.5; VLT=0.57; SHGC = 0.25 29.57 0.51%
RO1.2 U=0.49; VLT=0.6; SHGC = 0.27 29.53 0.64%
RO1.3 U=0.48; VLT=0.59; SHGC = 0.27 29.50 0.74%
RO1.4
(Retrofit Case1)
U=0.33; VLT=0.46; SHGC = 0.23
29.32
1.35%
RO1.5 U=0.28; VLT=0.6; SHGC = 0.41 29.10 2.08%
RO1.6 U=0.19; VLT=0.38; SHGC = 0.25 29.02 2.36%
RO2.0
(Baseline)
1.8 inch 20 PSI Rigid Insulation
29.72
0%
Roof
Insulation
RO2.1 2.8 inch 20 PSI Rigid Insulation 29.11 2.05%
RO2.2 3.8 inch 20 PSI Rigid Insulation 28.91 2.72%
RO2.3
(Retrofit Case 1)
4.8 inch 20 PSI Rigid Insulation
28.59
3.83%
Existing
Building:
Exterior Wall
RO3.0 (Baseline) Bare Concrete 28.15 5.29%
RO3.1 Added furring strips 29.72 0%
RO3.2
(Retrofit Case 1)
Added insulation R2
27.37
7.93%
RO3.3 Added insulation R4 27.20 8.49%
RO3.4 Added Insulation R6 27.10 8.84%
RO3.5 Added Insulation R8 27.05 9.01%
RO 4.0 Bare Concrete 29.72 0%
New
Construction:
Exterior Wall
RO4.1
(Retrofit Case 1)
Concrete + 2x4 wood framing
28.61
3.73%
RO4.2 Concrete 2 x 4, R-11 insulation 27.39 7.85%
RO4.3 Concrete 2 x 4, R-13 insulation 27.30 8.14%
RO4.4 Concrete 2 x 4, R-15 insulation 27.27 8.25%
RO4.5 Concrete 2 x 4, R-19 insulation 27.18 8.57%
RO4.6 Concrete 2 x 4, R-21 insulation 27.16 8.62%
RO5.0 (Baseline) CAV 29.72 0%
HVAC
System
RO5.1 VAV 28.10 5.47%
RO5.2
VAV + VRF + Dedicated Outside
Air System
27.66
6.93%
Lighting RO6.1 LED lighting 27.53 7.36%

Figure 4.10 shows that the building retrofit on exterior wall has higher averaged energy saving
potentials compared with energy saving potentials of roof retrofit option or glazing retrofit options.
The HVAC and lighting retrofit options selected for this building has higher energy saving
capability than glazing retrofit option and roof retrofit option but lower energy saving capability
than the exterior wall retrofit options.
104

Figure 4.10: EUI (kBtu/ft2) of different retrofit options

Figure 4.11: Energy Savings Rankings

25.50
26.00
26.50
27.00
27.50
28.00
28.50
29.00
29.50
30.00
EUI (kBtu/ft2)
Retrofit Options
EUI Rankings of all retrofit options (kBtu/ft2)
105

Table 4.32: Energy savings rankings
Energy Savings Rankings
Retrofit Option EUI (kBtu/ft2) EUI Improvement
Baseline 29.72 0%
RO1.1 29.57 0.51%
RO1.2 29.53 0.64%
RO1.3 29.50 0.74%
RO1.4 29.32 1.35%
RO2.1 29.11 2.05%
RO1.5 29.10 2.08%
RO1.6 29.02 2.36%
RO2.2 28.91 2.72%
RO4.1 28.61 3.73%
RO2.3 28.59 3.83%
RO3.1 28.15 5.29%
RO5.1 28.10 5.47%
RO5.2 27.66 6.93%
RO6.1 27.53 7.36%
RO4.2 27.39 7.85%
RO3.2 27.37 7.93%
RO4.3 27.30 8.14%
RO4.4 27.27 8.25%
RO3.3 27.20 8.49%
RO4.5 27.18 8.57%
RO4.6 27.16 8.62%
RO3.4 27.10 8.84%
RO3.5 27.05 9.01%

4.3.1 Skylight retrofit – different glazing options
The skylight area of the baseline building accounts for 12.64% of the roof area. Figure 4.12
indicates that the glazing options selected for the building could improve the EUI by 0.51% to
2.36% compared with the baseline model. If energy saving potential is the only consideration for
retrofit options selection, all the glazing type below could be used for improving the energy
efficiency of the building.
106

Figure 4.12: EUI and energy savings (%) of different skylight options
4.3.2 Roof option – improved insulation
Figure 4.13 shows that the selected roof options could contribute to around 2.05% to 3.83% of
EUI reduction. The thicknesses of rigid insulation for the baseline model, RO2.1, RO2.2 and
RO2.3 are 1.8inch, 2.8inch, 3.8 inch and 4.8 inch respectively.

Figure 4.13: EUI and energy savings capabilities (%) of different roof options
29.72
29.57
29.53
29.50
29.32
29.10
29.02
0.00%
0.51%
0.64%
0.74%
1.35%
2.08%
2.36%
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
28.6
28.8
29
29.2
29.4
29.6
29.8
Baseline RO1.1 RO1.2 RO1.3 RO1.4 RO1.5 RO1.6
ΔEUI (%)
EUI (kBtu/ft2)
Skylight Options
EUI and Energy Saving Potential of Different Skylight Retrofit
Total EUI EUI Improvement
29.72
29.11
28.91
28.59
0%
2.05%
2.72%
3.83%
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
3.00%
3.50%
4.00%
4.50%
28.00
28.20
28.40
28.60
28.80
29.00
29.20
29.40
29.60
29.80
30.00
Baseline RO2.1 RO2.2 RO2.3
ΔEUI (%)
EUI ( kBtu/ft2)
Roof Options
EUI and Energy Saving Potential of Different Roof Retrofit Options
EUI (kBtu/ft2) EUI Improvement
107

4.3.3 Existing exterior wall – improved insulation
The existing building area accounts for 47.7% of the total building floor area and 76.6% of the
total conditioned space in the whole building. Figure 4.14 shows that adding interior wood furring
strips (RO3.1) and insulation (RO3.2, RO3.3, RO3.4 and RO3.5) could highly increase the energy
savings potentials. The EUI improves from 5.29% to 9.01% as insulation with higher R value is
added into the furring space. The increment rate of EUI improvement decreases as the R value of
insulation in the furring strips increases.

Figure 4.14: EUI and energy savings (%) of different existing exterior wall options
4.3.4 New construction exterior wall- improved insulation
The new construction area accounts for 52.3% of the total building floor area and around 31 % of
the new constructed area is conditioned. Figure 4.15 indicates that the adding wood framing and
insulation into the furring space of newly constructed wall will greatly improve the EUI reduction.
29.72
28.15
27.37
27.20
27.10
27.05
0.00%
5.29%
7.93%
8.49%
8.84%
9.01%
0.00%
1.00%
2.00%
3.00%
4.00%
5.00%
6.00%
7.00%
8.00%
9.00%
10.00%
25.50
26.00
26.50
27.00
27.50
28.00
28.50
29.00
29.50
30.00
Baseline RO3.1 RO3.2 RO3.3 RO3.4 RO3.5
ΔEUI (%)
EUI (kBtu/ft2)
Exterior Wall (Existing) Options
EUI and Energy Saving Potential of Different Existing Exterior Wall Retrofit
Options
EUI (kBtu/ft2) EUI Improvement
108

Figure 4.15: EUI and energy savings (%) of different exterior wall options (New construction)
4.3.5 HVAC system retrofit– different HVAC systems
The three different types of HVAC system being compared are CAV, VAV and combination of
VAV and VRF system (VAV is used in studio area and woodshop while the rest of the room is
using VRF and dedicated outside air system). Figure 4.16 indicates that VAV system could reduce
the EUI by 5.47% and the EUI is further reduced by 6.93% when VRF system is adopted for the
building.

Figure 4.16: EUI and energy savings (%) of different HVAC system options
29.72
28.61
27.39
27.30
27.27
27.18 27.16
0.00%
3.73%
7.85%
8.14%
8.25%
8.57% 8.62%
0.00%
1.00%
2.00%
3.00%
4.00%
5.00%
6.00%
7.00%
8.00%
9.00%
10.00%
25.50
26.00
26.50
27.00
27.50
28.00
28.50
29.00
29.50
30.00
Baseline RO4.1 RO4.2 RO4.3 RO4.4 RO4.5 RO4.6
ΔEUI (%)
EUI (kBtu/ft2)
Exterior Wall (New Construction) Options
EUI and Energy Saving Potential of Different Existing Exterior Wall Retrofit
EUI (kBtu/ft2) EUI Improvement
29.72
28.10
27.66
0%
5.47%
6.93%
0%
1%
2%
3%
4%
5%
6%
7%
8%
26.50
27.00
27.50
28.00
28.50
29.00
29.50
30.00
Baseline RO5.1 RO5.2
ΔEUI (%)
EUI (kBtu/ft2)
HVAC System Retrofit
EUI and Energy Saving Potential of Different HVAC Retrofit Options
EUI (kBtu/ft2) EUI Improvement
109

4.3.6 Lighting retrofit option
Figure 4.17 shows that replace the existing fluorescent lighting with LED lighting could reduce
the EUI of the baseline model by 7.36%.

Figure 4.17: EUI and energy savings (%) of different lighting options
4.4 Lifecycle cost
The lifecycle cost estimations of applying different single retrofit options are summarized below.
Lifecycle cost for two different lifetimes were studied in this thesis, which are 15 years and 30
years respectively.
4.4.1 Lifecycle cost comparisons of different retrofit options in 15 years lifetime
Table 4.33 shows that all the single retrofit options do not save lifecycle cost in the 15-year lifetime
compared with the baseline model. Table 4.34 indicates that RO1.2 (one of the glazing retrofit
option) has the cheapest lifecycle cost while the RO4.6 (Improved insulation in new construction
exterior wall) has the highest lifecycle cost in 15 years compared with other single retrofit options.
Lifecycle cost of the cheapest retrofit option RO1.2 is 0.06% more than the baseline lifecycle cost
while the lifecycle cost of the most expensive retrofit option RO4.6 is 2.88% more than then the
lifecycle cost of the baseline model.

29.72
27.53
0%
7.36%
0%
1%
2%
3%
4%
5%
6%
7%
8%
26.00
26.50
27.00
27.50
28.00
28.50
29.00
29.50
30.00
Baseline RO6.1
ΔEUI (%)
Axis Title
Lighting Retrofit
EUI and Energy Saving Potential of Lighting Retrofit
EUI (kBtu/ft2) EUI Improvement
110

Table 4.33: Lifecycle cost of single retrofit option in 15 years life time
Lifecycle cost of single retrofit option in 15 years life time

Total
Energy
Cost
Investment
Cost
Maintenance
cost
RO
Lifecycle
Cost
Increment
Total
Lifecycle
Cost
Lifecycle
Cost
Change %
Baseline 512352 489192 0 1001544 0 10280690
0.00%
RO1.1 511259 732711 0 1243970 242427 10523117
2.36%
RO1.2 511955 495969 0 1007924 6381 10287071
0.06%
RO1.3 511645 538066 0 1049711 48168 10328858
0.47%
RO1.4 507912 591788 0 1099700 98156 10378847
0.96%
RO1.5 520673 774808 0 1295482 293938 10574628
2.86%
RO1.6 513444 619434 0 1132878 131334 10412025
1.28%
Baseline 512352 2902846 116732 3531930 0 10280690
0.00%
RO2.1 504219 2950086 125193 3579499 47568 10328259
0.46%
RO2.2 504195 2997682 133717 3635594 103664 10384354
1.01%
RO2.3 497552 3045277 142242 3685072 153141 10433832
1.49%
Baseline 512352 7469 0 519820 0 10280690
0.00%
RO3.1 497142 81068 0 578210 58390 10339081
0.57%
RO3.2 490150 83101 0 573250 53430 10334121
0.52%
RO3.3 488720 83526 0 572246 52426 10333116
0.51%
RO3.4 487872 83999 0 571871 52051 10332741
0.51%
RO3.5 487435 84424 0 571859 52039 10332729
0.51%
Baseline 512352 1358404 0 1870755 0 10280690
0.00%
RO4.1 505177 1579066 0 2084243 213488 10494178
2.08%
RO4.2 494567 1634069 0 2128636 257881 10538571
2.51%
RO4.3 493696 1638616 0 2132312 261557 10542247
2.54%
RO4.4 493515 1640998 0 2134514 263759 10544449
2.57%
RO4.5 492967 1640132 0 2133099 262344 10543034
2.55%
RO4.6 492888 1674347 0 2167235 296480 10577170
2.88%
111

Baseline 512352 1067843 559646 2139841 0 10280690
0.00%
RO5.1 461122 1135987 567782 2164892 25051 10305741
0.24%
RO5.2 454658 1204202 626819 2285679 145838 10426529
1.42%
Baseline 512352 134972 569475 1216800 0 10280690
0.00%
RO6.1 439194 885126 0 1324319 107519 10388210
1.05%

Figure 4.18: 15 years lifecycle cost comparisons of all single retrofit options

10100000
10150000
10200000
10250000
10300000
10350000
10400000
10450000
10500000
10550000
10600000
Lifeycle Cost ($)
Reotrofit Options
15 Year Lifecycle Cost Comparisons of Single Retrofit Options
112

Table 4.34: 15 years lifecycle cost rankings
15 years lifecycle cost rankings
Baseline Total Lifecycle Cost Lifecycle cost Increment %
Baseline 10280690 0.00%
RO1.2 10287071 0.06%
RO5.1 10305741 0.24%
RO2.1 10328259 0.46%
RO1.3 10328858 0.47%
RO3.4 10332741 0.51%
RO3.5 10332729 0.51%
RO3.3 10333116 0.51%
RO3.2 10334121 0.52%
RO3.1 10339081 0.57%
RO1.4 10378847 0.96%
RO2.2 10384354 1.01%
RO6.1 10388210 1.05%
RO1.6 10412025 1.28%
RO5.2 10426529 1.42%
RO2.3 10433832 1.49%
RO4.1 10494178 2.08%
RO1.1 10523117 2.36%
RO4.2 10538571 2.51%
RO4.3 10542247 2.54%
RO4.5 10543034 2.55%
RO4.4 10544449 2.57%
RO1.5 10574628 2.86%
RO4.6 10577170 2.88%

Figure 4.19: 15 years lifecycle Cost and Lifecycle Cost Increment (%)
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
3.00%
3.50%
10100000
10150000
10200000
10250000
10300000
10350000
10400000
10450000
10500000
10550000
10600000
Baseline
RO1.2
RO5.1
RO2.1
RO1.3
RO3.4
RO3.5
RO3.3
RO3.2
RO3.1
RO1.4
RO2.2
RO6.1
RO1.6
RO5.2
RO2.3
RO4.1
RO1.1
RO4.2
RO4.3
RO4.5
RO4.4
RO1.5
RO4.6
Lifecycle cost increment (%)
15 Years Lifecycle cost
Retrofit Options
15 Years Lifecycle Cost ($) and Lifecycle Cost Increment (%)
15 Years Lifecycle Cost Lifecycle Cost Increment %
113

4.4.2 Lifecycle cost comparisons of different retrofit options in 30 years lifetime
Table 4.35 and Figure 4.20 show that all the single retrofit options do not save lifecycle cost
compared with the baseline model in the 30-year lifetime. Table 4.36 indicates that RO1.2 (one of
the glazing retrofit option) has the cheapest lifecycle cost while the RO4.6 (Improved insulation
in new construction exterior wall) has the highest lifecycle cost in 15 years compared with other
single retrofit options. Lifecycle cost of the cheapest retrofit option RO1.2 is 0.06% more than the
baseline lifecycle cost while the lifecycle cost of the most expensive retrofit option RO4.6 is 2.88%
more than then the lifecycle cost of the baseline model.
Table 4.35: 30 years lifecycle cost comparisons of different retrofit options
30 years lifecycle cost comparisons of different retrofit options
Baseline
Energy
Cost
Investment
Cost
Maintenance
cost
RO
Lifecycle
Cost
Increment
Lifecycle
Cost
Adjusted
Lifecycle
Cost %
Change
Baseline 863151
489192
201547 1553890 0
13782789 0.000%
RO1.1 861171
732711
301877 1895759 341869
14124658 2.480%
RO1.2 862230
495969
204339 1562538 8648
13791437 0.063%
RO1.3 861684
538066
221683 1621434 67544
13850332 0.490%
RO1.4 855430
591788
243817 1691035 137145
13919933 0.995%
RO1.5 875547
774808
319221 1969577 415687
14198476 3.016%
RO1.6 863842
619434
255207 1738482 184592
13967381 1.339%
Baseline 863151
2902846
191621 3957618 0
13782789 0.000%
RO2.1 849198
2950086
205510 4004794 47176
13829965 0.342%
RO2.2 848858
2997682
219503 4066043 108425
13891214 0.787%
RO2.3 837720
3045277
233496 4116493 158875
13941664 1.153%
Baseline 863151
7469
0 870620 0
13782789 0.000%
RO3.1 836406
81068
0 917474 46854
13829643 0.340%
RO3.2 824014
83101
0 907115 36495
13819284 0.265%
RO3.3 821472
83526
0 904998 34379
13817168 0.249%
RO3.4 819960
83999
0 903958 33339
13816128 0.242%
RO3.5 819180
84424
0 903604 32985
13815773 0.239%
114

Baseline 863151
1358404
0 2221555 0
13782789 0.000%
RO4.1 849979
1579066
0 2429045 207490
13990279 1.505%
RO4.2 831128
1634069
0 2465197 243643
14026431 1.768%
RO4.3 829602
1638616
0 2468219 246664
14029453 1.790%
RO4.4 829263
1640998
0 2470261 248707
14031495 1.804%
RO4.5 828243
1640132
0 2468375 246820
14029609 1.791%
RO4.6 828091
1674347
0 2502438 280884
14063672 2.038%
Baseline 863151
1067843
1124994 3055989 0
13782789 0.000%
RO5.1 778615
1135987
1179120 3093723 37734
13820523 0.274%
RO5.2 767604
1204202
1287800 3259605 203617
13986406 1.477%
Baseline 863151
134972
1124994 2123118 0
13782789 0.000%
RO6.1 742633
885126
1068307 2696065 572948
14355737 4.157%

Figure 4.20: 30 years lifecycle cost comparisons of all single retrofit options

13400000
13500000
13600000
13700000
13800000
13900000
14000000
14100000
14200000
14300000
14400000
Lifecycle Cost ($)
Retrofit Options
30 Year Lifcycle Cost Comparisons of Single Retrofit Options
115

Table 4.36: 30 years lifecycle cost rankings
30 years lifecycle cost rankings

30 years lifecycle cost Lifecycle cost change %
Baseline 13782789 0.00%
RO1.2 13791437 0.06%
RO3.5 13815773 0.24%
RO3.4 13816128 0.24%
RO3.3 13817168 0.25%
RO3.2 13819284 0.26%
RO5.1 13820523 0.27%
RO3.1 13829643 0.34%
RO2.1 13829965 0.34%
RO1.3 13850332 0.49%
RO2.2 13891214 0.79%
RO1.4 13919933 1.00%
RO2.3 13941664 1.15%
RO1.6 13967381 1.34%
RO5.2 13986406 1.48%
RO4.1 13990279 1.51%
RO4.2 14026431 1.77%
RO4.3 14029453 1.79%
RO4.5 14029609 1.79%
RO4.4 14031495 1.80%
RO4.6 14063672 2.04%
RO1.1 14124658 2.48%
RO1.5 14198476 3.02%
RO6.1 14355737 4.16%

116

Figure 4.21: 30 years lifecycle cost and lifecycle cost increment (%)
4.4.3 Energy usage comparisons between the baseline model and retrofit case 1
Table 4.37 shows that the retrofit case 1 could reduce EUI by 23.89% and save 15 Year and 30
Year energy cost savings by 27.2% compared with the baseline model.
Table 4.37: Baseline model and retrofit option energy consumption comparisons
Baseline model and retrofit case 1 energy consumption comparisons
Baseline Model Retrofit Case 1
Energy
Improvement %
EUI 29.72292354 22.62144502 23.89%
Total Energy (MMBTU) 1364.558 1038.533 23.89%
IES VE Energy Output Baseline Model Retrofit Case 1
Energy/EUI
Improvement %
Total lights energy (MMBtu) 281.465 137.548 51.13%
ApHVAC distribution fan 174.727 46.203 73.56%
ApHVAC AAHPs heating energy (MMBtu) 2.009 9.29 -362.42%
ApHVAC heat rej fans/pumps energy (MMBtu) 2.643 4.31 -63.07%
ApHVAC DX cooling systems energy (MMBtu) 41.405 67.529 -63.09%
ApSys boilers energy (MMBtu) 80.76 80.76 0.00%
ApHVAC other heating plant energy (MMBtu) 421.014 332.358 21.06%
Energy Summary Baseline Model Retrofit Case 1
Energy
Improvement %
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
3.00%
3.50%
4.00%
4.50%
13400000
13500000
13600000
13700000
13800000
13900000
14000000
14100000
14200000
14300000
14400000
Baseline
RO1.2
RO3.5
RO3.4
RO3.3
RO3.2
RO5.1
RO3.1
RO2.1
RO1.3
RO2.2
RO1.4
RO2.3
RO1.6
RO5.2
RO4.1
RO4.2
RO4.3
RO4.5
RO4.4
RO4.6
RO1.1
RO1.5
RO6.1
Lifecycle Cost Increment (%)
Lifecycle Cost ($)
Retrofit Options
30 Year Lifecycle Cost ($) and Lifecycle Cost Change (%)
30 Years Lifecycle Cost Lifecycle Cost % Increment
117

Equipment Energy (MMBtu) 360.535 360.535 0.00%
Lighting Energy (MMBtu) 281.465 137.548 51.13%
Heating Energy (MMBtu) 423.023 341.648 19.24%
Cooling Energy (MMBtu) 41.405 67.529 -63.09%
Fan Energy (MMBtu) 177.37 50.513 71.52%
Electricity Baseline Model Retrofit Case 1 Cost Saving %
Annual Electricity (kWh) 252268.25 180568.41 28.42%
Annual Natural Gas (Therms) 4230.23 3416.48 19.24%
Annual Electricity Cost (Year 2017) 37587.97 26904.69 28.42%
Annual Natural Gas Cost (Year 2017) 4230.23 3416.48 19.24%
Annual Energy Cost (Year 2017) 41818.20 30321.17 27.49%

4.4.4 Lifecycle cost comparisons of the baseline model and retrofit case 1
Lifecycle cost of retrofit case 1 is 9% and 9.5% higher than the lifecycle cost of the baseline
model in 15 years lifetime and 30 years lifetime respectively.
Table 4.38: Lifecycle cost comparisons between the baseline model and retrofit case 1
Lifecycle cost comparisons between the baseline model and retrofit case 1

Baseline
Model
Retrofit
Option
Cost
Increment
Cost
Increment
%
Investment Cost 5960726 7338229 1377503 23.1%
Glazing 489192 591788 102596 21.0%
Roofing 2902846 3045277 142431 4.9%
Existing Exterior Wall 7469 81068 73599 985.4%
New Constructed Exterior Wall 1358404 1579066 220662 16.2%
HVAC System 1067843 1155905 88062 8.2%
Lighting 134972 885126 750153 555.8%
15th Year Maintenance Cost 1245855 703621 -542234 -43.5%
Glazing 0 0 0
Roofing 116733 142242 25509 21.9%
Existing Exterior Wall 0 0 0 0.0%
New Constructed Exterior Wall 0 0 0 0.0%
HVAC System 559646 561379 1733 0.3%
Lighting 569476 0 -569476 -100.0%
30th Year Maintenance Cost 2453252 2193229 -260023 -10.6%
Glazing 201547 243817 42269 21.0%
Roofing 191621 233496 41875 21.9%
Existing Exterior Wall 0 0 0 0.0%
New Constructed Exterior Wall 0 0 0 0.0%
HVAC System 1124994 1180416 55421 4.9%
118

Lighting 935089 535501 -399588 -42.7%
15 Years Energy Cost 512352 372361 -139991 -27.3%
30 Years Energy Cost 863151 628127 -235024 -27.2%
15 Years Lifecycle Cost 7718933 8414212 695279 9.0%
30 Years Lifecycle Cost 9277129 10159585 882456 9.5%

Figure 4.22: 15 years lifecycle cost comparisons between the baseline model and retrofit case 1

Figure 4.23: 30 Years lifecycle cost comparisons between the baseline model and retrofit case 1
5960726
7338229
1245855
703621
512351.5565
372361.0405
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
9000000
Baseline Model Retrofit Case 1
Lifecycle Cost ($)
15 Year Lifecycle Cost Comparisons: Baseline Model VS Retrofit Case 1
Investment Cost 15 Year Maintenance Cost 15 Year Energy Cost
5960726
7338229
2453252
2193229
863151
628127
0
2000000
4000000
6000000
8000000
10000000
12000000
Baseline Model Retrofit Case 1
Lifecycle Cost ($)
30 Year Lifeycle Cost Comparisons: Baseline Model VS Retrofit Case 1
Investment Cost 30 Year Maintenance Cost 30 Year Energy Cost
119

4.4.5 Investment cost comparisons of the baseline model and retrofit case 1
Table 4.39 shows that that the investment cost of retrofit cost is 24% higher than the baseline
model. The lighting system used in the retrofit case 1 is the main contributor for the investment
cost increment compared with the baseline model. The roofing and new exterior wall system are
the secondary factors which contributes the higher investment cost of retrofit case 1.
Table 4.39: Investment cost comparisons between the baseline model and retrofit case 1
Investment cost comparisons between the baseline model and retrofit case 1

Baseline
Model
Investment
Cost ($)
Retrofit
Case 1
Investment
Cost ($)
Investment
Increment/retrofit
investment
cost %
Investment
Increment
（$ ）
RO Investment
Increment/total
investment cost
Glazing
489192 591788 21%
102596 1.72%
Roof
2902846 3045277 5%
142431 2.39%
Existing Exterior
Wall 7469 81068 985%
73599 1.23%
New Exterior Wall
1358404 1579066 16%
220662 3.70%
HVAC
1067843 1204202 13%
136359 2.29%
Lighting
134972 885126 556%
750153 12.58%
Total
5960726 7386527 24%
1425800

Figure 4.24: Investment cost distribution of the baseline model
489192,
8%
2902846, 49%
7469, 0%
1358404, 23%
1067843, 18%
134972, 2%
Baseline Model: Investment Cost Distribution
Glazing
Roof
Existing Exterior Wall
New Exterior Wall
HVAC
Lighting
120

Figure 4.25: Investment cost distribution of retrofit case 1

Figure 4.26: Investment cost comparisons between the baseline model and retrofit case 1

591788, 8%
3045277, 41%
81068, 1%
1579066, 22%
1204202, 16%
885126,
12%
Retrofit Case 1 Investment Cost Distribution
Glazing
Roof
Existing Exterior Wall
New Exterior Wall
HVAC
Lighting
489192
2902846
7469
1358404
1067843
134972
591788
3045277
81068
1579066
1204202
885126
0
500000
1000000
1500000
2000000
2500000
3000000
3500000
Glazing Roof Existing Exterior
Wall
New Exterior
Wall
HVAC Lighting
Investment Cost ($)
Investment Cost Comparisons: Baseline Model vs Retrofit Case 1
Baseline Model Retrofit Case 1
121

4.5 Conclusions
Based on current assumptions and calculations, it is shown that all the retrofit options could
improve the energy efficiency of the baseline model, however, none of them pay back in 15 years
lifetime or 30 years lifetime and none of them saves lifecycle cost compared with the baseline
model. Thus, the improvements which were chosen are not substantially better than the
improvements that would be required for a Title 24 building. Detailed analysis and further
discussions are shown in chapter 5.

122

5. Discussion
5.1 Introduction
Different than the previous research, the baseline model used in this thesis incorporated the
information from the existing building and Title 24 requirements. The cost estimation of the
baseline model also included the cost for Title 24 improvements. Results in chapter 4 show that
all the individual building retrofit option could reduce the energy usage, however, compared with
the baseline model, none of them save lifecycle cost in 15 years and 30 years lifetime if a lifecycle
cost approach is taken. Thus, the hypothesis is disapproved in this research. The detailed analysis
of the result and other findings are provided below.
5.2 Investment cost and energy cost savings
Chapter 4 shows that compared with the baseline model, none of the retrofit options save lifecycle
cost in either a 15 years or 30 years lifetime. The major reason is because the investment cost of
the selected retrofit options is too expensive so that the energy cost savings are not able to pay
back the investment cost in either 15 years lifetime or 30 years lifetime, even if the maintenance
cost is not considered at this stage. Figure 5.1 shows that all the investment cost increment is much
higher than energy cost savings except RO 5.1 (using VAV system instead of CAV system).

Figure 5.1: Investment cost increment ($/ft²) vs energy cost savings
-5
0
5
10
15
20
ΔCost/area ($/ft²)
Investment Cost increment ($/ft²) vs Energy Cost Savings ($/ft2)
investment cost increment 15 Year energy cost savings per square feet
30 Year energy cost savings per square feet
123

5.3 Cost effectiveness analysis
Cost ranking equations were first introduced by Qian Wang (2016) to compare the cost saving
capabilities of a single retrofit option in a long-term perspective. The equation is modified and it
is shown below.
Cost effectiveness =
𝐸𝐶𝑀 𝑖 − 𝐸𝐶𝑀 𝑏𝑎𝑠𝑒𝑙𝑖𝑛𝑒 + 𝑅𝑀𝐶 𝑖 − 𝑅𝑀𝐶 𝑏𝑎𝑠𝑒𝑙𝑖𝑛𝑒 𝑂𝐶
𝑖 − 𝑂𝐶
𝑏𝑎𝑠𝑒𝑙𝑖𝑛𝑒
The cost effectiveness could be an indicator whether the retrofit options are able to save money in
a long-term perspective. All the retrofit options involved in this research have a higher investment
cost than the baseline model. The equation listed above indicates that retrofit option will be able
to save money in the studied life time if it could reduce the annual energy cost and its cost
effectiveness is between -1 and 0. Based on the calculation result in Table 5.1, the cost
effectiveness of all individual retrofit options is not between -1 and 0. Thus, all of these individual
retrofit options are not able to save money in 15 years or 30 years lifetime compared with the
baseline model. It could be seen from Table 5.1 and Figure 5.2 that the cost effectiveness of RO1.1
and RO1.3 and RO 4.1 has much higher cost effectiveness than other retrofit options. It means that
the investment cost of these retrofit options is too expensive to be paid back due to their limited
energy cost save capabilities. If the retrofit option has negative cost effectiveness, it means that
this type of retrofit option is not able to save energy cost, such as RO1.6 (one type of the glazing
options).
Table 5.1: 15 years and 30 years cost effectiveness comparisons
Baseline 15 Years cost effectiveness 30 Years cost effectiveness
RO1.6 -120.2388271 -267.7799833
RO1.5 -35.32193019 -33.20367192
RO5.1 0.647813231 0.936608352
RO6.1 0.69482577 0.421779492
RO3.5 2.088490541 1.183478083
RO3.4 2.126340677 1.205128919
RO3.3 2.218447511 1.257859902
RO3.2 2.406579733 1.365226685
RO5.2 3.69211143 3.230271722
RO3.1 3.839143849 2.183198886
RO2.1 6.889376878 4.404531409
RO2.3 12.07154679 7.668379965
RO4.5 13.53350147 7.515270152
RO4.4 14.00275317 7.783225843
RO4.3 14.01999852 7.796368979
RO4.2 14.50031634 8.053091218
RO2.2 14.79079526 9.203786269
RO4.6 15.23291722 8.456492531
124

RO1.2 16.09735598 9.961473431
RO1.4 22.11111008 18.18873775
RO4.1 29.75619239 16.20747458
RO1.3 68.16691908 46.5649027
RO1.1 221.95324 173.1227016

Figure 5.2: 15 years cost effectiveness rankings of retrofit options
-150
-100
-50
0
50
100
150
200
250
15 Years Cost Effectiveness Rankings of Retrofit Options
125

Figure 5.3: 30 years cost effectiveness rankings of retrofit options

Figure 5.4: Cost Effectiveness Rankings Comparison of Retrofit Options
-300
-250
-200
-150
-100
-50
0
50
100
150
200
3o Year Cost Effectiveness Rankings of Retrofit Options
126

5.4 EUI improvement (%) vs annual energy cost reduction (%)
Figure 5.5 shows that the higher EUI reduction does not guarantee sufficient energy cost savings.
The RO3.2, RO3.3, RO3.4, RO3.5, RO4.1, RO4.2, RO4.3, RO4.4, RO4.5 and RO4.6, which adds
insulation into the building furring spaces could contribute to higher EUI reduction than HVAC
system and lighting system, however, it has much lower energy cost saving capabilities than that
of HVAC and lighting retrofit. This figure could be used for building designer who are seeking
balance between Title 24 compliance and annual energy cost savings.

Figure 5.5: Correlations between EUI improvement (%) and annual energy cost reduction (%)
5.5 EUI improvement (%) vs investment cost increment (%)
Figure 5.6 indicates that the LED lighting retrofit option used for this building contributes to higher
investment cost increment even though it has relative higher energy savings. This figure is suitable
for designer and building owners who conduct building retrofitting within a certain budget. For
the studied building, adding insulation into the furring space of existing wall is relatively cheap
investment to reduce the EUI if budget (first cost) is the prime factor for retrofit options selections.
127

Figure 5.6: Correlations between EUI improvement (%) and investment cost increment (%)
5.6 EUI improvement (%) vs lifecycle cost increment (%)
Table 5.2 shows that retrofit options (highlighted with red) such as adding insulation to the
building envelope tends to have lower lifecycle cost increment percentages if a longer lifetime is
used for lifecycle study. It is because building envelope has relatively lower maintenance cost than
the maintenance cost of HVAC system and lighting equipment. Thus, using longer lifetime (more
than 5 or 10 year) or comparing retrofit cost savings with different lifetime is recommended for
building owners who consider lifecycle cost as one of decision factors for building retrofit options
selections, especially for building owners of institutional buildings such as school buildings.
Table 5.2: 15 years lifecycle cost increment (%) vs 30 years lifecycle cost increment (%)

Investment cost
increment %
15 years lifecycle cost
increment %
30 years lifecycle cost
increment %
RO1.1 4.293% 2.386% 2.50%
RO1.2
0.119% 0.063% 0.06%
RO1.3 0.862% 0.474% 0.49%
RO1.4
1.809% 0.966% 1.00%
RO1.5 5.036% 2.894% 3.04%
RO1.6
2.296% 1.293% 1.35%
RO2.1 0.833% 0.468% 0.35%
RO2.2
1.672% 1.020% 0.79%
RO2.3 2.511% 1.508% 1.16%
RO3.1
1.298% 0.575% 0.34%
RO3.2 1.333% 0.526% 0.27%
RO3.3
1.341% 0.516% 0.25%
128

RO3.4 1.349% 0.512% 0.24%
RO3.5
1.357% 0.512% 0.24%
RO4.1 3.063% 1.640% 1.18%
RO4.2
3.827% 1.962% 1.36%
RO4.3 3.890% 1.988% 1.37%
RO4.4
3.923% 2.005% 1.38%
RO4.5 3.911% 1.993% 1.37%
RO4.6
4.386% 2.257% 1.57%
RO5.1 1.201% 0.247% 0.28%
RO5.2
2.404% 1.436% 1.49%
RO6.1 13.226% 1.058% 4.20%

Figure 5.7: 15 years lifecycle cost change % vs 30 years lifecycle cost change %

129

5.7 Rebates and incentives
Different Rebates and incentives are provided by Southern California Edison (SCE) for non-
residential customers. For LED lighting, the rebates for lighting fixture varies between 45 dollars
to 300 dollars per unit based on the type of the fixture. (SCE, 2017). Figure 5.8 shows that the
LED lighting (RO6.1) is cheaper than the fluorescent lighting in 15 years life time when lighting
rebates per fixture is more than 150 dollars. However, in 30 years life time, it is showed that the
investment cost of LED lighting will not able to payback even if 400 dollars rebates per fixture is
provided. This is due to the extra replacement cost of lighting fixture for 30 years lifecycle cost
estimation. (The LED lighting life expectancy is assumed as 17 years while the life expectancy for
fluorescent lighting is assumed as 3.42 years)

Figure 5.8: The impact of lighting rebates on 15 years and 30 years lifecycle cost increment (%)

-3.00%
-2.00%
-1.00%
0.00%
1.00%
2.00%
3.00%
4.00%
5.00%
0 50 100 150 200 250 300 350 400 450
The impact of lighting rebates on 15 years and 30 years lifeycycle cost increment
(%)
15 year Lifecycle cost increment % 30 year lifecycle cost increment %
Poly. (15 year Lifecycle cost increment %) Linear (30 year lifecycle cost increment %)
130

Table 5.3: The impact of lighting rebates on 15 Year and 30 Year lifecycle cost increment (%)
Rebates/fixtur
e
0 10 20 30 40 50 60 70 80 90 100
Cost/ft2 19.28 19.128 18.97 18.81 18.65 18.49 18.33 18.18 18.02 17.86 17.7
15 year
Lifecycle cost
increment %
1.046
%
0.978
%
0.908
%
0.837
%
0.767
%
0.696
%
0.626
%
0.555
%
0.485
%
0.414
%
0.344
%
30 year
lifecycle cost
increment %
4.157
%
4.106
%
4.054
%
4.001
%
3.949
%
3.896
%
3.843
%
3.791
%
3.738
%
3.686
%
3.633
%

Rebates 0 200 300 400
Cost/ft2 15.812 14.07 12.33
15 years
lifecycle
cost
increment %
-
0.503%
-
1.278%
-
2.054%
30 years
lifecycle
cost
increment %
3.002% 2.424% 1.845%

5.8 HVAC outdoor unit downsizing/upsizing
The lifecycle cost analysis of all the retrofit options listed above only consider the energy cost,
maintenance cost and investment cost of the corresponding retrofit option. However, each
individual retrofit option could affect the cooling load of the building, which consequently will
affect the size of the HVAC outdoor and indoor unit. Based on the cost model developed in chapter
4, the cost of HVAC outdoor and indoor unit such as packaged air conditioner for CAV and VAV
system, outdoor unit and indoor unit for VRF system is correlated with the cooling load. Thus, it
is important to investigate the HVAC equipment cost change resulting from the change of cooling
load when different retrofit options are being modelled. Figure 5.9 shows the comparisons of 15
years cost savings and HVAC equipment cost change due to re-sizing. It is concluded that HVAC
equipment cost change could not be neglected while calculating the lifecycle cost.
131

Figure 5.9: Energy cost savings in 15 years and HVAC equipment cost change due to upsizing
and downsizing.
5.9 Discussion of the results
The hypothesis of this research is energy retrofits are cheaper than they look if a lifecycle cost
approach is taken. The UCLA graduate art studios was chosen as the case study. The baseline
model for energy simulation and cost analysis was developed upon information from both existing
building conditions and minimum requirements of Title 24 energy code. This means that the
baseline building was an already improved version of the existing building. Retrofit case 1 was
recommended by the local design team and its performance is around 20% better than the baseline
model. Meanwhile, different individual retrofit options were proposed to improve the energy
efficiency and cost effectiveness of the baseline model. There are six types of energy retrofit
options being modelled for this thesis, which are skylight retrofit options with different glazing
types (RO1.0 - RO1.6), roof retrofit options with improved insulation (RO 2.0-RO2.3), existing
exterior wall retrofit options with improved insulation (RO3.0-RO3.5), new construction exterior
wall retrofit options with improved insulation (RO4.0-RO4.6), HVAC system retrofit options with
different types of HVAC systems (RO5.0-RO5.2) and lighting retrofit options (RO6.0-RO6.1).
Energy simulation through IES VE and lifecycle cost analysis were conducted to quantify the
energy savings and cost savings of individual energy retrofit options in a long-term perspective
(15 years and 30 years). Energy saving ranking model (EUI improvement rankings) and a cost
effectiveness ranking model was used to evaluate and rank the energy saving capability and
lifecycle cost saving capability of different individual retrofit options. It was initially planned that
the single retrofit options with higher energy saving and less lifecycle cost than the baseline model
will be clustered to generate energy retrofit packages, these energy retrofit packages will then be
-120000
-100000
-80000
-60000
-40000
-20000
0
20000
40000
15 years energy cost savings and HVAC equipment cost change due to upsizing or
downsizing
15 Years Energy Cost savings HVAC Equipment Price Change
132

implemented to improve the energy efficiency and cost effectiveness of the baseline model and
retrofit case 1. However, based on the results in chapter 4, although all the individual retrofit
options could reduce the EUI of the Title 24 baseline model by 0.51% to 8.84%, none of the
proposed individual retrofit options will save the lifecycle cost when compared to a Title 24. The
selected individual retrofit options will increase lifecycle cost of the baseline model by 0.06% and
4.16% if they are implemented. Thus, the current individual retrofit options used for analysis are
unable to improve the energy efficiency and cost effectiveness of the baseline model in a long-
term perspective (15 years and 30 years). Consequently, retrofit plans and retrofit packages which
could reduce both energy and lifecycle cost will not be generated through implementing the
proposed retrofit options. The result also shows that the EUI of retrofit case 1 is 23.89% lower
than the baseline model EUI while the lifecycle cost of retrofit case 1 is 9% and 9.5% higher than
the baseline model in 15 years and 30 years lifetime respectively. In conclusion, the hypothesis is
disapproved based on the current result and part of the objectives of this thesis cannot be achieved.
5.9.1 Why the hypothesis is disapproved?
There are several reasons that the proposed individual energy retrofit option could not help to save
the lifecycle cost compared to the baseline model even if these energy retrofit options could
improve the EUI of the baseline model by 0.51% to 9.01%. The potential reasons and explanations
are listed below.
5.9.1.1 High investment cost
The major reason is that the investment cost of the single retrofit option is much higher than their
energy cost savings, in other words, the investment cost and maintenance cost increment from the
proposed individual retrofit option could not be paid back during the studied lifetime. (15 years
and 30 years). Figure 5.1 shows that the investment cost increment by applying RO 5.1 into the
baseline model (using VAV system instead of CAV system) could be paid back by the energy cost
savings within 30 years, however, if maintenance and replacement cost is considered, RO 5.1 will
increase the lifecycle cost of the baseline model by 0.27%.
5.9.1.2 Evaluation of the baseline model
The second major reason is related to the baseline model. The energy savings percentage and
energy cost savings of certain retrofit options are highly dependent on the energy efficiency of the
baseline model and climate zone where the building is located. The energy savings capability of
certain retrofit option varies when it is applied for different buildings or when it is applied for
different climate zones. Different than other building retrofit studies, the baseline model used in
this thesis is developed upon the Title 24 energy code requirement while the baseline model used
for other retrofit studies are usually the existing building with higher energy consumption. It is
recommended that more case studies shall be conducted to evaluate the impact of climate zone and
building types on the energy savings capabilities and lifecycle cost saving capabilities of different
retrofit options.

133

5.9.1.3 Limitations of existing retrofit options and recommendations.
Due to the timeline of the thesis, only energy and cost analysis of individual retrofit options were
conducted at this stage. Table 4.32 shows that the energy saving percentage by the individual
retrofit option varies between 0.51% and 9.01% while lifecycle cost increment percentage by the
individual retrofit option varies between 0.06% and 4.157%. It is recommended that energy retrofit
packages (combination of different retrofit options) with higher energy saving potentials shall be
evaluated in the future work. Energy retrofit options such as passive ventilation, PV panels, adding
advanced controls to the existing HVAC system and lighting system could also be evaluated.
Furthermore, energy simulation tools which enables parallel simulations and parametric analysis
are strongly recommended for future study.
5.10 Research findings
There are two major findings of this thesis.
5.10.1 Consider HVAC equipment downsizing/upsizing for building envelope retrofit
Previous research does not encounter the cost benefits due to the HVAC equipment downsizing
for building envelope retrofit. Figure 5.9 in Chapter 4 shows the there is significant investment
cost change due to the change of HVAC equipment sizing brought by different retrofit options,
especially building envelop retrofit. Thus, practitioners shall encounter the investment cost change
from HVAC equipment re-sizing while calculate the lifecycle cost of building envelope retrofit.
5.10.2 The impact of rebates and incentives on lighting retrofits
Rebates and incentives need to be considered for building retrofit, especially for lighting retrofit.
Figure 5.8 in Chapter 4 shows that the lighting rebates could have a huge impact on lifecycle cost
calculation for lighting retrofit and the investment cost could be paid back in a shorter time if
lighting rebates with higher amount are considered. Thus, practitioners shall be aware the rebates
and incentives while calculating the lifecycle cost of different lighting retrofit options.
134

6. Future work
6.1 Future work and conclusions
The scope of this research only considers one building and one climate zone. The result might not
be applicable for other building types as well as buildings located in different climate zones. Since
climate zone and building types could have a huge impact on the energy consumption and cost
benefits, it is recommended case studies across the different climate zones could be conducted to
generate comparative database. Also, the energy saving capability and cost saving capability by
retrofit options are also highly dependent on the energy efficiency of the baseline model. The
baseline model used in this thesis incorporates the information of the existing building and
minimum requirement from the title 24 energy code, which is different from previous research
where the existing building is usually regarded as the baseline model. Thus ，the energy saving
ranking and cost saving ranking result from this thesis might not be applicable for different
buildings or buildings using different baseline models. However, the energy ranking model and
cost effectiveness ranking model are still applicable for future case studies.
Furthermore, it is necessary to collect more energy efficient retrofit options such as passive
ventilation, advanced controls, and more advanced building integrated system for further studies.
Cost studies especially lifecycle cost analysis can be very difficult and time-consuming. There are
multiple of economic factors involved in the lifecycle cost studies which adds the uncertainties of
future cost prediction. The cost information collection/estimation process can be very tedious.
Therefore, a lot of future work could be further developed.
The output of this thesis could be generalized into the following points:
1. Energy retrofit measures/retrofit options could reduce the energy usage of the building.
However, they might not be able to be paid back even if lifecycle cost study is conducted.
2. Cost effectiveness ranking model is suitable for comparing the long-term cost savings
capabilities of different retrofit options while sensitivity analysis might not be applicable
to provide energy rankings for all type of energy rankings. For example, adding variable
speed drive for HVAC system could not be regarded as a range of variables.
3. Building envelope retrofit can have very expensive investment cost and it is necessary to
consider cost change resulted from HVAC equipment downsizing/upsizing.
6.2 Explore more factors related to building energy
As it is mentioned at the beginning of this chapter 5, further study could incorporate more energy
retrofit options which could further improve the energy efficiency of the baseline model. The
following strategies and factors could also be tested:
• Natural ventilation
• Daylight harvest and lighting dimming strategies
• Other HVAC system such as chilled beam system
• Window wall ratio (WWR)
• Higher efficiency plumbing system
• Variable energy sources: install PV panels
135

All these factors listed above are common strategies which could be used to improve the energy
efficiency. The energy savings capabilities of the different retrofit options are highly dependent on
energy usage of the baseline model and climate zones. Thus, it is important to establish a consistent
baseline model to investigate the influence of climate zones on the energy saving capabilities of
different retrofit options. Furthermore, retrofit packages instead of single retrofit options could be
analyzed.
6.3 Test and evaluate the assumptions of cost information and economic factors
The main cost resources for this study includes RS Means, two cost reports from local cost
estimation firms and other online resources. The investment cost of different retrofit options could
be estimated based on the resources above while the cost related to maintenance as well as
equipment life expectancy might need to be further validated with varies of facility management
firms. Also, there are many economic factors and terms involved in lifecycle cost estimations, such
as energy cost, discount rate, inflation. Variation in different predictions of economic factors and
future energy costs should be compared to determine the variations in the lifecycle cost.
6.4 Rebates and incentives
There are multiple rebates and incentive resources for non-residential and residential energy
efficiency programs in California. For example, the savings by design program provides both
whole building approach and system approach to collect the incentives. Both design team and
building owners could get incentives based on the energy savings. Financial incentives for
equipment upgrading including lighting, HVAC, refrigeration, variable speed drives and building
envelope retrofits are also provided by Southern California Gas and Southern California Edition.
However, only LED lighting rebates from Southern California Edison (SCE) were studied in this
thesis. It is recommended that rebates and incentives of different resources could be summarized
for future lifecycle cost study. This is perfectly appropriate when considering the socieal costs and
benefits of reducing energy consumption.

136

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Abstract (if available)

Abstract Buildings consume 39% of CO₂ emissions and 70% of the electricity load in the United States (USGBC,2017). To improve the energy efficiency of the buildings, government has established building energy codes and guidelines to facilitate the energy savings in the building sector, such as Title 24 in the California Building Code. However, more than 75% of the existing residential and commercial buildings in California were constructed before the California Building Codes were established (California Air Resources Board, 2013). In addition, the degradation of the building equipment and systems could have significant impact on the building energy efficiency and the total energy usage. Thus, building retrofits will play an important role in improving the energy efficiency of building and energy savings. In terms of existing buildings, building retrofits can be categorized as case-by-case based upon the types of the buildings and requirements of the building owner. During the decision-making process of selecting the optimum building retrofits plan, it is difficult for building consultants, architects and engineers to efficiently evaluate the cost- effectiveness and energy savings due to retrofitting. In this thesis, energy modelling techniques (IES VE) and life-cycle cost analysis are implemented to provide evaluations and recommendations for UCLA Graduate Art Studio retrofits in California. Different building retrofits options are proposed and evaluated to indicate the trade-off between energy savings and economic benefits. The results show that the building retrofitting could have 23% reduction on energy use intensity (EUI). However, building retrofits options with the higher energy savings also have the higher life-cycle cost due to high maintenance, equipment cost and labor fees. The result of the thesis is expected to support the institutional building owners to apply efficient building retrofit strategies.

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Asset Metadata

Creator Chen, Tian (author)

Core Title Building retrofitting evaluation: Energy savings and cost effectiveness of building retrofits on Graduate Art Studios at the University of California, Los Angeles

School School of Architecture

Degree Master of Building Science

Degree Program Building Science

Publication Date 07/18/2018

Defense Date 04/26/2018

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

Tag building retrofit,cost effectiveness,energy savings,IES VE,lifecycle cost,OAI-PMH Harvest

Format application/pdf (imt)

Language English

Contributor Electronically uploaded by the author (provenance)

Advisor Konis, Kyle (committee chair), Koffman, Henry (committee member), Schiler, Marc (committee member)

Creator Email nancy.chen1222@gmail.com,nancychen.aiesec.unnc@gmail.com

Permanent Link (DOI) https://doi.org/10.25549/usctheses-c89-17210

Unique identifier UC11668932

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Legacy Identifier etd-ChenTian-6412.pdf

Dmrecord 17210

Document Type Thesis

Format application/pdf (imt)

Rights Chen, Tian

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...

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