analysis of trust attributes of value streams in …
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The Pennsylvania State University
The Graduate School
Department of Architectural Engineering
ANALYSIS OF TRUST ATTRIBUTES OF VALUE STREAMS
IN HOME ENERGY AUDITING PROCESSES
A Dissertation in
Architectural Engineering
by
Fu-Ju Wu
2016 Fu-Ju Wu
Submitted in Partial Fulfillment
of the Requirements
for the Degree of
Doctor of Philosophy
August 2016
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The dissertation of Fu-Ju Wu was reviewed and approved* by the following:
David R. Riley
Associate Professor of Architectural Engineering
Dissertation Advisor
Chair of Committee
Robert M. Leicht
Assistant Professor of Architectural Engineering
James D. Freihaut
Professor of Architectural Engineering
Gül E. Kremer
Professor of Industrial and Manufacturing Engineering
Chimay J. Anumba
Professor of Architectural Engineering
Head of the Department of Architectural Engineering
*Signatures are on file in the Graduate School
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ABSTRACT
In the past decade, significant investments have been made to advance residential energy auditing
methods to enable reduced energy consumption in the residential sector. Previous research has identified
four barriers that make homeowners less likely to implement energy improvements: (1) lack of
information, (2) financial concerns, (3) lack of available workforce to implement improvements, and (4)
conflicts of interest between auditors and homeowners. The goal of this research is to develop methods to
measure value-trust exchange in home energy audits in a quantitative way and assess the impacts of trust
attributes on homeowner’s intention to take action. Additionally, this research seeks to improve the
efficiency and effectiveness of home energy audits. Literature review and industry practice are used to
identify types of value-trust exchanges in the home energy audit process. These value attributes are used
to examine value-adding interactions leading to information delivery and trust relationships between
homeowners and auditors. Models are developed to evaluate 90-minute home audits and evaluate the
types and efficiency of value-trust exchanges that take place during in-home energy audits. Forty-eight
surveys and thirty in-house audit recordings were collected to develop statistical models of trust
attributes, constraints on energy improvements and homeowners’ personal characteristics. The
contributions to this research are (1) the systematic identification of value-trust exchanges which take
place during home energy audits, (2) a systematic measurement of value-trust exchange in home energy
audits, and (3) identification of practical activities related to critical trust attributes that may be utilized to
improve the accumulation of trust during audit process planning and design.
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TABLE OF CONTENTS
LIST OF FIGURES ix
LIST OF TABLES xii
DEDICATION xiv
CHAPTER 1 INTRODUCTION 1
Problem Statement 2 1.1
Research Goal and Objectives 3 1.2
1.2.1 Research goal 3
1.2.2 Research objectives 4
Research Approach 5 1.3
Expected results and contributions 6 1.4
CHAPTER 2 LITERATURE REVIEW 8
The Home Energy Audit Market 8 2.1
Professional Accreditations for Auditors and Energy Audit Methods 9 2.2
2.2.1 The Residential Energy Service Network (RESNET) 10
2.2.2 The Building Performance Institute (BPI) 10
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2.2.3 The National Energy Leadership Corps (NELC) 11
Comparison of Energy Audit Practices 14 2.3
2.3.1 Audit flow between the BPI and the NELC Energy Audit 16
Challenges of Current Home Energy Audit Delivery 19 2.4
2.4.1 Lack of access to clear and reliable information 20
2.4.2 Lack of financing 21
2.4.3 Lack of trust between auditors and homeowners 22
2.4.4 Lack of skilled workers 22
Motivation of homeowners to increase adoptions of energy audits 22 2.5
Strategies in response to the challenges of home energy audits 24 2.6
Value Dimensions of Home Energy Audits 26 2.7
Trust attributes informing the creation of a value-trust framework 27 2.8
Characterizing Trust Attributes 31 2.9
Chapter Summary and Research Approach 32 2.10
CHAPTER 3 METHODOLOGY 34
Research Goal 34 3.1
3.1.1 Research Objectives 35
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3.1.2 Research Approach 38
Lean perspective of value exchange 38 3.2
Effort and Value 39 3.3
Value- Trust Model 43 3.4
Approaches to Measure Value-Trust Exchange 46 3.5
CHAPTER 4 SURVEY DESIGN 50
Survey design – Homeowners’ confidence level 50 4.1
Survey design – In-house walkthrough trust attributes 51 4.2
Survey Design – Homeowners’ Intention to Implement Energy 4.3
Improvements and Practical Constraints 54
Survey data computation 56 4.4
Other Survey Design Variables 58 4.5
4.5.1 Classification of investment cost 58
4.5.2 Worldview 61
Chapter Summary 62 4.6
CHAPTER 5 DATA COLLECTION AND CODING INSTRUMENT 64
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Data collection methods 64 5.1
Survey Data Demographic 65 5.2
Audit Recording Demographic 67 5.3
Frequency of Response 67 5.4
Correlations of trust attributes 69 5.5
Coding Instrument of Eight Trust Attributes 71 5.6
Classifying Value-Trust Attributes Based on Home Zones (Home-System)76 5.7
Coding Tools 78 5.8
Chapter Summary 80 5.9
CHAPTER 6 DATA ANALYSIS 81
Developing Simple Regression Models for Home Energy Audit Value-Trust 6.1
Exchange 81
6.1.1 Linear Mixed-Effects Models 88
Methods of Data Analyses, Model Collinearity and Model Fit 89 6.2
Mixed effects model selection with SPSS 98 6.3
6.3.1 Interpretation of the mixed effects model E 100
Chapter Summary 123 6.5
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CHAPTER 7 CONCLUSIONS 125
Summary of Findings 125 7.1
Research Contributions 129 7.2
7.2.1 Identification of value-trust exchange in an in-house audit 129
7.2.2 Survey design and the characterization of the measurable trust attributes in
energy audit process 129
7.2.3 Develop theoretical framework of audit process with practical cases 130
7.2.4 Developed an organizing framework for audit coding 131
Research Limitations and Future Research 132 7.3
REFERENCES 134
APPENDIX A – CODING INSTRUMENT OF IN-HOUSE ENERGY AUDIT 138
APPENDIX B – STATISTICAL RESULTS OF MODE 143
APPENDIX C – SAMPLE AUDIT REPORT 152
APPENDIX D – SURVEY SAMPLES 156
APPENDIX E – IRB APPROVAL 175
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LIST OF FIGURES
Figure 1.1.U.S. Energy Flow (2013), quadrillion BTU based on U.S. Energy Information Administration (EIA) ............. 2
Figure 2.1.Building Energy Data Book,2013. DOE Energy and Environmental and Renewable Energy ........................ 9
Figure 2.2 Residential home energy value chain map (Riley et al. (2012), Building America report 6.1) .................... 13
Figure 2.3.Workflow difference between the traditional BPI energy audit and the NELC home energy audit ............ 18
Figure 2.4.Reasons homeowners make home improvements (Palmer K. 2013) .......................................................... 23
Figure 2.5.Motivators to increase adoption of home energy efficiency improvements (Palmer K. 2013) ................... 23
Figure 3.1. Research flow illustrates the architecture of the research processes and objectives in each chapter ...... 37
Figure 3.2 Initial framework of value model: Layers of value types in the home energy audit. .................................. 42
Figure 3.3. Trust- value exchange model - the categorized tasks of an assessment walkthrough with corresponded
trust attributes and value dimension.( Wu & Riley, 2015) ........................................................................................... 45
Figure 3.4 The relationships between independent and dependent variables ............................................................ 49
Figure 4.1. The relationship between independent and dependent variables ............................................................. 54
Figure 5.1. 48 survey respondents were collected from State College and nearby communities ................................ 65
Figure 5.2.Survey response rate by gender .................................................................................................................. 66
Numbers of survey delivered to communities in Pennsylvania regions ....................................................................... 66
Figure 5.3.Numbers of surveys sent to communities near State College ..................................................................... 66
Figure 5.4.Screen shot of coding matrix in StudioCode ............................................................................................... 78
Figure 5.5 Screen shot of instance footnote in an in-house audit ................................................................................ 79
Figure 6.1 Model 1 represents the relationship between homeowners’ overall trust level in home energy audits and
homeowners’ intention to implement energy improvement ....................................................................................... 83
Figure 6.2 Model 2 represents the relationship between audit process and homeowners’ overall trust level in home
energy audits. .............................................................................................................................................................. 83
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Figure 6.3 Model 3 includes measurable trust variables to study homeowners’ implementation of energy
improvements .............................................................................................................................................................. 83
Figure 6.4 Model 3 focuses on the relationship between practical constraints on energy improvements and
homeowners’ intention to implement energy improvement ....................................................................................... 84
Figure 6.5. Model 5 includes homeowners’ personal characteristics, such as worldview, gender, and confidence level
to study the relationships between these variables and homeowners’ intention to implement energy improvement84
Figure 6.6 Categorical variables in each group to for the prediction of homeowners’ homeowners’ intention to
implement energy improvement ................................................................................................................................. 87
Figure 6.7 Model 6.4 accumulates groups of measurable variables to study the comprehensive influences of
homeowners’ actions to energy improvements........................................................................................................... 92
Figure 6.8.Normal Probability Plot (left) and Histogram (right) – trust attributes against homeowners’ overall trust
level of home energy audit .......................................................................................................................................... 94
Figure 6.9.Normal Probability Plot (left) and Histogram (right) – trust attributes against homeowners’ actions to
energy improvements .................................................................................................................................................. 95
Figure 6.10.Normal Probability Plot (left) and Histogram (right) – constraints of energy improvements against
homeowners’ actions to energy improvements........................................................................................................... 97
Figure 6.11 Mixed effect model E with eight trust attributes, homeowners’ overall trust of home energy audit and
cost category and priority of recommendations to against to homeowners’ action to energy improvements. ....... 102
Figure 6.12 Mixed effect model F of seven trust attributes, constraints of energy improvements, homeowners’
overall trust of home energy audit and cost category and priority of recommendations. ........................................ 106
Figure 6.13 Model G is created to indicate the relationships between “time (%) spent on each zone” and
“Homeowners’ intentions to implement energy improvements. ............................................................................... 111
Figure 6.14 Mode H, Relationship I and J discuss the relationships between "time spent on trust attributes" and
homeowners' overall trust level" and "intentions to energy improvements" ............................................................ 117
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Figure 6.15 Combined results of Model E,F and H to present (1) significant factors, (2) time spent on significant trust
attributes can increase homeowners' implementations of energy improvements of their homes. .......................... 121
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LIST OF TABLES
Table 2.1 Summary of standard procedures of ASHRAE energy audit for commercial buildings with the marked
procedures that occurs in the existing models of residential energy audit between RESNET, BPI and NELC (RESNET
(2014), BPI (2014) ASHRAE (2011) and NELC (2013)) .................................................................................................. 15
Table 2.2 Summarized critical barriers to energy improvements from the previous research (Palmer et al, 2013).... 20
Table 2.3 Strategies of the BPI and the NELC energy audit in response to critical barriers of home energy audits (Wu
and Riley, 2015) ........................................................................................................................................................... 25
Table 2.4. Trust attributes identified from research to respond to existing barriers of home energy improvements . 30
Table 3.1: Examples of effort contributed to value adding processes and the corresponded value dimensions and
objectives of value ....................................................................................................................................................... 43
Table 3.2 Summary table of trust attributes and trust behaviors ............................................................................... 48
Table 4.1 Summary table of trust attributes and justified survey questions ............................................................... 53
Table 4.2 Constraints and corresponding questions of energy improvements ............................................................ 55
Table 4.3. Computation of weight of maximum time to implement energy improvements........................................ 58
Table 4.4 Examples of common tasks recommended in our audit cases with its cost range, assumed maximum time
to implement it and the corresponded weight as following. ....................................................................................... 60
Table 4.5 Worldview†: Intrinsic and extrinsic motivations of each type of worldview (UtilityPulse program, Shelton
group, 2013). ............................................................................................................................................................... 62
Table 5.1 Information on the 30 audited houses (Source: www.zillow.com) .............................................................. 67
Table 5.2 Response rate of grouped variables ............................................................................................................. 68
Table 5.3 Spearman Correlation between trust variable during the in-house audit ................................................... 70
Table 5.4. Criteria for coding interactions/ conversation during audit for each trust attribute. ................................ 73
Table 5.5 Instances of tasks in home system and the corresponded value dimension and trust attributes in home
zones ............................................................................................................................................................................ 77
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Table 5.6 Example key words and contents of trust attributes of coding .................................................................... 79
Table 6.1.Grouped variables are presented with measureable options ...................................................................... 88
Table 6.2. Summary of candidate models with corresponding AIC, BIC, and grouping predicators. ........................... 98
Table 6.3. Type III tests of fixed effects for the mixed effects model E ...................................................................... 103
Table 6.4. Estimates of fixed effects for model E ....................................................................................................... 103
Table 6.5. Type III tests of fixed effects for the mixed effects model F ...................................................................... 107
Table 6.6. Estimates of fixed effects for model F ....................................................................................................... 107
Table 6.7.The average time in minutes and proportion of time in percentage spent on each space zone of thirty
audit houses. .............................................................................................................................................................. 110
Table 6.8 Cases comparison of in-house audits ......................................................................................................... 114
Table 6.9. The average time spent on each trust attribute in an in-house audit. ...................................................... 116
Table 6.10 Summary of observed interactions in the in-house audit that were found to contribute to homeowners'
intention to implement improvements. ..................................................................................................................... 123
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DEDICATION
To my son
William Cheng-Yu DeGraw
January 13th, 2016 – January 23
rd, 2016
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Chapter 1
Introduction
In the United State, the majority of the residential housing is comprised of single family
homes and a large number of these homes were built prior to the development of energy codes
and standards. The U.S. Energy Information Agency (EIA) states that in the year 2013, 21.13% of
the annual energy consumption of the United States was used in the residential sector, 17.93% in
the commercial sector, 31.46% in the industrial sector, and 27.01% in transportation (EIA, 2013).
The White House Council on Environmental Quality (CEQ) has identified homeowners’ lack of
access to clear and reliable information, lack of access to financing, and lack of availability of a
skilled workforce to perform retrofits as the primary barriers to a self-sustaining home energy
upgrade market (2009 CEQ report). Palmer (2013) also states key challenges facing homeowners
in need of home energy efficiency improvements were found to be: 1) a lack of information, 2) a
lack of financing, and, 3) a lack of trust relationship between auditors and homeowner to
undertake home energy upgrades. The purpose of this research is to identify and prioritize
opportunities to improve efficiency of auditing process in a manner that can increase likelihood of
action by the homeowners.
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Literature in service industries has documented that a trust relationship is critical in
maintaining satisfaction between clients and service providers (Coulter, 2002). Barriers of
information and finance are challenging to overcome during an audit process. However, the
establishment of a trustful relationship is also worthy to develop between homeowners and
auditors and can potentially contribute to homeowners’ intention and action to implement energy
upgrades. Methods to establish trust and the contributions trust can make in the home energy
audit process are deeply explored through this research
Problem Statement 1.1
Traditional home energy audit practices focus on the justification of home energy
efficiency investments based on return of investment (Riley, 2012). Limited research has been
performed on the improvement of the home energy audit process based on a view of the audit as a
service, and the related application of service-based business development, such as the
development of trust. Various opportunities exist to improve audit processes based on unique
Figure 1.1.U.S. Energy Flow (2013), quadrillion BTU based on U.S.
Energy Information Administration (EIA)
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conditions in homes and in a manner that generates value for both homeowners and energy
efficiency service providers. Multiple variables can influence homeowners’ intention to act upon
home energy improvement recommendations. Research is needed to distinguish significant
variables influencing homeowners’ intention to energy improvement through based on value-
oriented interactions between energy service providers and homeowners.
The research presented here focuses on value characterization of the trust relationship in
home energy audit processes. It seeks to identify value-trust exchange instances based on
observation and from homeowners’ feedback to identify relationships between effort invested in
an audit process and the identification of resulting value-trust exchanges contributing to
homeowners’ intentions to make home energy improvements.
Research Goal and Objectives 1.2
1.2.1 Research goal
The goal of this research is to characterize value-trust transactions in the home energy
audit process while seeking to overcome barriers to the advancement of home energy efficiency
in single family homes. The approach includes the design of a framework and evaluation metric
for qualitative and quantitative value dimension/trust attributes that can take place during a home
energy audit. This framework is then used to study the relationships between value-trust
distribution methods and the audit impact to homeowners’ intentions to implement energy
improvements. The use of a post-audit survey and measurement of value-trust instances during
recorded audits are demonstrated and tested to determine the feasibility and potential application
of the results of this research.
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1.2.2 Research objectives
This research studies home energy audit process and seeks to characterize value-trust
exchanges that encourage implementation of energy improvements. To do so, four objectives are
pursued:
1. Conduct literature review to explore the existing home energy audit research and
industry practices with a focus on the comparison of existing auditing methods
and characteristics of value and trust attributes as well as the key indicators of
value-trust exchange in home energy audit.
2. Develop a survey instrument to evaluate the audit process with defined trust
attributes, practical constraints to making improvements, and homeowner
characteristics that may influence homeowners’ intention to implement energy
improvements. In addition, develop a coding instrument to examine audit
recordings designed to identify and classify value-trust during the audit process.
3. Construct a series of value-trust models for statistical analysis that enable the
study of relationships between variables in the audit process and the
homeowners’ overall self-identified trust level in the energy audit and resulting
influences on intentions of homeowners to implement energy improvements.
4. Evaluate results and identify critical interactions that encourage homeowners to
act upon energy improvements and implications of these results on the design of
home energy audit program and process design.
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Research Approach 1.3
A home energy audit is a technical service in which a trained auditor uses observation
and diagnostic equipment to evaluate the energy efficiency features of a house and the situational
conditions such occupancy and use patterns that influence energy use. This research focuses on
identifying value-trust exchange during audit process and characterizing trust attributes. This
research is established based on the program of the National Energy Leadership Corp at the
Pennsylvania State University in which college students are trained to deliver free or low-cost
audits in homes in their local community (Riley et al & The NELC, 2013). After receiving energy
an audit and the customized energy audit report, including priorities of recommendations and
levels of cost investments, homeowners are asked to volunteer for a post-audit survey developed
for this research. In addition, recordings of audit process are used to classify time spent during the
audit in different zones of house and to detect instances of value-trust exchange during the audit.
In this research, a home energy audit is treated as a production process which contains
both operational (technical characteristics) and intellectual (service characteristics) tasks in a
service process. The research applies the methodology of “case study method of observation”
combined with “survey investigation”. The former helps to examine the characteristics of a
particular process and defines the environment in which the research takes place. The latter is
used to collect overall feedback on the audit service and the distinguish relationships between the
process and homeowners’ intentions to implement energy improvements. The exploratory nature
of this research is intended to examine and better explain the home energy audit value-trust
exchange and the development and testing of a systematic value-trust evaluation of home energy
audits. The following steps will be pursued to accomplish this research:
Define of effort, value, and trust attributes in the home energy audit process (Chapter 2).
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Develop a survey and a coding instrument to identify indicators and research variables in
home energy audits (Chapter 4).
Provide a justification of the audit recording process and the analysis methods for this
data (Chapter 5).
Compute value formula and value model to represent impact of value-trust variables on
intention to implement energy improvement implementations (Chapter 6).
Provide statistical methods to analyze survey data to and testify relationships between
grouped variables and homeowners’ intention to energy improvements. (Chapter 6).
Summarize results and contributions of research with an emphasis on guiding more
detailed studies of audit delivery and continuous improvement (Chapter 7).
Expected results and contributions 1.4
1. Definition of value-trust exchange in home energy audit process – This research
adopts value-trust attributes from the literature to study in-home energy audits. In
doing so, new and additive forms of value exchange are identified with examples
in support of measuring value-oriented home auditing practices.
2. Development of a value-trust metric and a coding instrument to identify and
classify value-trust exchange during a home energy audit. The metric enables the
evaluation of a home energy audit process in a quantitative way and for value-
delivery to be linked to the time and location of effort expended during a 90-
minute home energy audit.
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3. Development of statistical analysis approach and model for studying the
relationships between grouped variables and homeowners’ intention to energy
improvements. This process will also verify the value of the post-audit survey as
an instrument to inform the continuous improvement of audit practices.
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Chapter 2
Literature Review
This chapter presents a review of literature and industry practice and consists of two main
parts. The first section discusses the background of home energy audit market and comparison
between professional home energy audit processes and delivery methods. The second section
explores the challenges of home energy audits and the studies of the value dimensions and trust
attributes used in the service industries. The discussion includes the evaluation of trust
relationships and the development of value- trust exchange framework. The methods to study the
home audit process are also presented and justified including survey design, coding of field
observations and statistical methods.
The Home Energy Audit Market 2.1
Data of Department of Energy (DOE, 2013) indicated that 111.1 million homes were
built before 2005 in the United State, with the average single-family home as 2,838 square feet,
941 square feet for multi-family homes, and 1,062 square feet for mobile homes (Figure 2.1).
Residential houses have the similar systems and components as commercial buildings, but in
more condensed spaces. Residential houses include building envelope, systems of heating,
cooling, lighting and the occupants with their unique conditions. The small-scale and personal
nature of homes influences homeowner interests in energy retrofits and energy auditing services,
which are often delivered through public programs and utilities, as opposed to in the open market
(Ketchman K., 2016). However, home energy audit is widely considered as the first step in
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making home more efficient (DOE, 2013). A home energy audit can help a homeowner assess
how much energy a home consumes and identify where the energy efficiency can be improved.
Common opportunities include improving insulation, repairing air leaks, and updating of heating,
cooling, and lighting systems. Audits may also detect safety and health issues that exist in homes,
many of which may also have energy implications (NELC curriculum, 2013).
Professional Accreditations for Auditors and Energy Audit Methods 2.2
There are various professional audit methods recognized in the United States which
provide a basis for how traditional home audit processes are approached. The most well-known
authoritative entities of residential energy audit are the Residential Energy Service Network
(RESNET) and the Building Performance Institute (BPI). Both RESNET and BPI have
developed audit approaches and certification curriculums to train professional auditors, as well as
Figure 2.1.Building Energy Data Book,2013. DOE Energy and Environmental and
Renewable Energy
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provide audit services national wide (BPI & RESNET website 2014). Each is described in more
detail below.
2.2.1 The Residential Energy Service Network (RESNET)
RESNET classifies energy audits a one of two types: a home energy survey or a general
energy audit (RESNET website, 2014). A home energy survey is presented as a visual inspection
that focuses on general energy performance of an existing home without using diagnostic testing
equipment. The general energy audit expands on the home survey by collecting details on energy
usage information and energy cost analysis as well as including diagnostic testing with
specialized equipment, such as blower door testing, duct leakage testing, combustion analysis,
and infrared imaging. (RESNET website, 2014)
2.2.2 The Building Performance Institute (BPI)
Building Performance Institute (BPI) certified auditors provide energy audit through a
house-as-a-system approach that considers the interaction of the different components and
systems of a house affects the performance of the entire house. The BPI energy audit consists of
an interview with homeowner to identify their main concerns and house conditions, an interior
and exterior walk-through with several technical tests (such as blower door testing, infrared
imaging). Energy simulation tools are then used to explore the return on investment of packages
of energy efficiency investment. A detailed report with retrofit recommendations, and should a
retrofit take place, a second evaluation is used to verify the energy savings after implementation
of retrofits (BPI website 2014).
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2.2.3 The National Energy Leadership Corps (NELC)
The NELC is an alternative model for the delivery of home energy audits developed at
the Pennsylvania State University in which entry-level college students are trained to deliver free
of low-cost audits to homes in the local community. Through research and experimentation, the
NELC program has led to the development of a curriculum, an audit process model, data
collection tools, and reporting tools that enable college students to deliver retrofit- related
information and resources to homeowners. The NELC program also serves as the foundational
effort supporting this research and as the platform that will be used to deliver audits for local
community as research data samples.
Riley et al (2012) studies the value chain of home energy audit and how energy
efficiency upgrades are delivered to the marketplace. Through a series of process phases,
homeowner and house conditions are characterized and considered in the marketplace, and
energy solutions are presented to homeowners as a single or bundled package of energy
efficiency measurements (EEMs) that are considered feasible to upgrade by homeowners and
service providers.
The NELC audit is developed based on the belief that initial energy audit can be
delivered in a low cost approach and in a manner that is aligned with emerging energy and
sustainability programs in colleges and universities. Initial studies that informed the NELC
program design include broad research on the design of home energy audit process design
(Building America, 2013) which defined four types of audit delivery modes of do-it-yourself,
assisted, traditional, and whole house methods. (Hinsey, 2012) examined and demonstrated the
business case for low-cost energy assessment program design. (Mohr, 2012) examined the value-
adding processes of pre-audit surveys in the delivery of affective in-home audits. (Sprehn, 2015)
demonstrated the impact of customizing home audit reporting based on cognitive style and world
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view. Riley et al. also developed a generic representation of the value chain that can be used to
illustrate differences in variable approaches to the home audit process as Figure 2.2 (Riley et al.
(2012).
.
I. Homeowner engagement refers to the processes in which homeowners are engaged in
energy efficiency and can vary from do-it-yourself (DIY) upgrades, community based
weatherization efforts, utility-sponsored upgrades to professional contractors.
II. Home energy audit phase includes a range of methods used to gather data and
characterize the home including studies of community scale market evaluation, self-
audits conducted by homeowners, assisted audits in which technical support is provided
to homeowners, and traditional professional audits.
III. Characterization of data includes the organization and analysis of data based on
situational conditions, homeowner priorities, home conditions, utility data, and additional
monitoring and analytical tools.
IV. Upgrade analysis is used to evaluate energy efficiency measures as individual or
packages of recommendation, and inform recommendations made to justify variable
scales of investment of improvement and resulting energy savings.
V. The delivery of upgrades is then performed through do-it-yourself actions, specialty
contractors, general contractors, or whole-house energy services contractors.
13
Figure 2.2 Residential home energy value chain map (Riley et al. (2012), Building America report 6.1)
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Comparison of Energy Audit Practices 2.3
Multiple models of energy auditing exist in the energy audit industry. Focusing on
commercial buildings, the American Society of Heating, Refrigerating, and Air-Conditioning
Engineers (ASHRAE, 2011) defined three levels of audits, called ASHRAE Level 1, 2, and 3
audits. The ASHRAE Level 1 audit is a walk-through audit that identifies energy efficiency
measures (EEMs) with limited engineering time and cost to produce a report. ASHRAE Level 1
is generally sufficient for a small building which uses very little energy. The ASHRAE Level 2
audit is an energy survey and analysis, which is more detailed and requires proficiency and
thought to create a quality audit report. ASHRAE Level 2 includes basic inspection and the
balance of cost effective for buildings. The ASHRAE Level 3 audit is a detailed survey and
analysis that is designed to provide additional energy rigor for more expensive capital projects
where less risk is tolerated. All three levels of audits require a preliminary energy use analysis,
which involves the following steps:
A site visit and analysis of the utility bill to determine utility saving,
A summary of utility data and calculation of the energy use intensity (EUI),
Benchmarking to compare the site energy usage to similar sites in the same
regions.
Estimate of the energy and cost savings if the building were to meet an energy
intensity target.
Table 2.1 summarizes the procedures of three steps of ASHRAE energy audits for
commercial buildings with the marked characters of residential energy audits within RESNET,
BPI and NELC. It is clear the BPI audit covers most of the procedures ASHRAE requires for the
15
commercial buildings, whereas RESNET and the NELC assessments operate audit procedures in
the ASHRAE Level 1 and selective procedures in the ASHRAE Level 2.
Table 2.1 Summary of standard procedures of ASHRAE energy audit for commercial
buildings with the marked procedures that occurs in the existing models of residential energy
audit between RESNET, BPI and NELC (RESNET (2014), BPI (2014) ASHRAE (2011) and
NELC (2013))
ASHRAE
Level
Procedures of energy audit in the commercial sector,
by ASHRAE
Models of existing residential energy
audits and its presented procedures
RESNET BPI NELC
1
Walk-through survey • • •
Identify low-cost/no-cost recommendations • • •
Estimate low-cost/no-cost saving • •
Identify capital improvements • •
Estimate saving from utility rate change • •
Summary of utility data, the estimation of savings
associated with a rate change, the calculation of the
energy benchmarking and targeting
• • •
2
Detailed on-site survey • • •
A complete description of the facility, including an
equipment inventory, and energy balance. •
Measure key parameters • •
Estimate capital project costs and saving • •
Estimate saving if EUI met target
Meet with owner/operator to review
recommendations • •
3
Additional testing/ monitoring
•
Detailed system modeling/ simulation
•
Schematic recommendations for future upgrades • • •
Detailed description of recommended measures • •
Detailed life cycle cost estimates
•
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2.3.1 Audit flow between the BPI and the NELC Energy Audit
This research adopts the NELC energy audit for the auditing process study, which
emphasizes the value-oriented processes to conduct energy audits for residential houses. The
NELC home energy audit includes five steps to conduct an in-house audit and presentation of
findings and recommendations to homeowners as described below:
a. Sign-up / survey: A short on-line sign-up survey is used for homeowners to apply for an in-
house walkthrough assessment. The application includes basic information on home
conditions and residents, including year of construction, square footage, house orientation,
ceiling height, house structure, mechanical systems, and the numbers and age range of
residents. The primary use of the application is to enable potential homes to be screened
based on the ability to respond, and also to enable preliminary research on the home through
web resources.
b. Pre-audit interview: The in-home audit begins with a 30-minute scripted interview to learn
homeowners’ confidence levels, energy awareness, preferences, concerns, as well as recently
completed or planned home upgrades. The primary value of this interview includes
informing how time is spent during the walkthrough to investigate concerns and questions, as
well as to gain deep insight into the priorities and decision-making patterns of homeowners
that can be used to prioritize recommendations and improve the likelihood recommendations
will be well received by homeowners.
c. In-house walkthrough: A 60-90 minute in-house walkthrough is used to gather specific data
and information about the condition of the home as well as to gather pictures and
thermographic images of the home to inform recommendations.
17
d. Report delivery: After in-house visit, a six page, customized home energy report (sample in
Appendix A) is presented to homeowners including a summary of home energy use, key
issues identified in the audit walkthrough with the top five energy efficiency
recommendations.
e. Post-audit survey: A survey is delivered to the homeowner to evaluate the in-house
walkthrough including the experience of the homeowner overall as well as the intention of
homeowners to pursue the recommendations.
Figure 2.3 compares the workflow and objectives between the BPI audit and the NELC
assessment. The highlighted procedures state the differences between both models. For example,
the BPI audit includes diagnostic tests such as blower door and carbon monoxide testing as part
of the audit, while the NELC provides a pre-audit survey and scripted interviews to learn
homeowners’ preferences and to build trust relationships during the audit. Figure 2.3 illustrates
the comparison of workflow of both energy audits.
18
Pre audit interview
Whole House Walkthrough
Prioritize EEM Recommendations
2rd Round Whole House Walkthrough if apply incentive
Main concerns & house condition
Visual inspection
Completed and detailed report
Diagnostic Tests Infrared camera, Blower door, CO detector
EEM Implementations by homeowners
Work flow Objectives
Verify results of upgrade
NELC Home Energy Audit
Scripted Interview / survey
Whole House Walkthrough
Prioritize EEM Recommendations
Deliver report and explain EEM recommendations
Visual inspection & Infrared camera
Pre- audit survey Priorities & World view
Identify concerns, preview process & build Trust
Highlighted summary report
Encourage implementation of recommendations
Work flow Objectives
Deliver Survey Indicate homeowners’ feedback and intention to action
BPI Home Energy Audit
Figure 2.3.Workflow difference between the traditional BPI energy audit and the NELC
home energy audit
19
Challenges of Current Home Energy Audit Delivery 2.4
Although various home energy audit methods exist in the energy services marketplace,
there are significant challenges in these processes that contribute to limited market adoption.
These shortcomings include high audit costs, high skill requirements for home energy auditors,
and a lack of financing for home energy improvements that would make the audit worthwhile. It
is commonly understood that energy service providers achieve a low translation rate of home
audits to home energy upgrades. (Riley, 2012). Recent research has identified opportunities to
improve home energy audit practices. Notable opportunities include reducing process
inefficiencies such as wasted work effort in generating an audit, poor communication between
homeowners and audit professionals, lack of voice of the customer, lack of understanding by
auditors of consumer behavior and purchasing preferences, poor delivery of energy audit
information, and tendencies by energy service contractors to offer one-off transactions as opposed
to long term customer service (Riley et al, Building America Report 6.1, 2012 edit).
A survey included of nearly 500 home energy auditors and contractors in summer 2011
(Palmer et al, 2013) indicated that “half or more of their clients do not make any of the suggested
improvements recommended in an audit.” Table 2.2 summarizes the critical barriers for
homeowners to implement energy improvements for their homes. Up to 72% of survey
respondents identify financial barriers such as “cannot afford the recommended upgrade”, “high
cost of audit”, and up to 63% of respondents identify information barriers such as “lack of
understanding about the audit” and “not being awareness of the benefit of energy audit”. Also,
nearly 25% of survey respondents state that the barrier of “lack of trust in reliability and accuracy
of audit” contributes to their intention to not to enact home improvements.
20
Table 2.2 Summarized critical barriers to energy improvements from the previous
research (Palmer et al, 2013)
% of survey respondents
Critical barriers to adopt home energy audits
72% Homeowners cannot afford the upgrade that would be recommended
63% Homeowners lack of understanding about the information audit provided
50% Homeowners lack of awareness of audits in general as issues that are critical or major importance
42% High actual or perceived cost of audits
< 25% A lack of trust in the reliability and accuracy of audit
The “Recovery through Retrofit Report 2009” published by the White House Council on
Environmental Quality (CEQ, 2009) also identified three primary barriers to foster home energy
retrofit market (White House Report, 2009), which are “lack of access to information”, “lack of
financing”, and “lack of skilled workers”. These barriers are further explored below.
2.4.1 Lack of access to clear and reliable information
Homes are complex systems. Most homeowners have limited access to detailed
information about their home’s operation in general, and especially energy use. This coupled
with the high availability of low cost energy results in little attention paid to the details of
monthly utility bills. Few homeowners have the experience or judgment to make improvements to
their homes and often require advice to understand and gain confidence in the investments in
energy upgrades. Home energy audits are especially vivid and personal due to the face-to-face
interaction (Costanzo 1986). Yate and Aronson (1983) have describes several methods that
21
energy auditors can help homeowners understand their energy utility, for example, “use
homeowners’ owe bill to illustrate energy consumption and the alternatives to save energy.
Furthermore, indication of how much energy homeowners are losing each month by not investing
in energy expense (Costanzo 1986). In many cases, this advice comes from an individual with
variable expertise that is motivated to “sell” upgrades, which can lead to interest conflicts or
inflated promises of energy savings from home energy improvements (NELC curriculum, 2013).
The Shelton Group found that an overall feeling of disappointment by homeowners who did make
investments in audits and energy upgrades, and that most were not experiencing anything close to
the savings promised by auditors (Shelton Group, 2013).
2.4.2 Lack of financing
While the potential to reduce energy use in most homes is significant, the availability of
affordable energy can result in a less attractive return on investment for homeowners that have
capital to invest. In homes that lack capital, there is a need to provide financial assistance for
upgrades. This type of assistance has been challenging to administer and make available at scale.
Innovative financing methods related to utility or governmental sponsor enable energy upgrades
linked to tax payments, hold promise but require action by regional governments and have not
been widely adopted, such as the property-assessed clean energy (PACE) program that finances
for energy efficiency and renewable energy improvements on private property (PACE website,
2016). Coupled with the lack of access to reliable information, a significant proportion of public
and utility-based incentive programs for energy efficiency go unused (Palmer, 2013).
22
2.4.3 Lack of trust between auditors and homeowners
Riley (2012) and Palmer (2013) both found that “trust” is a major factor for homeowners
when they consider implementing energy improvements in their homes. Riley (2012) found that
most auditors focus on one-time sales interactions. Homeowners that resist the short-term sales
pitch are likely to hesitate in taking action after energy audits. Palmer (2013) found that
homeowners are not interested in home energy audits due to a lack of trust in the reliability and
accuracy of audits. Homeowners are less likely to take action if they feel uncertain about the
auditing process and the outcome of improvements.
2.4.4 Lack of skilled workers
A consequence of the lack of rigid energy codes and standards has been the limited
development of a broadly available workforce capable of retrofitting homes with new and
efficiency building systems. To respond to this issue, the Department of Energy (DOE) has
launched certified and accredited training programs, such as the weatherization and
intergovernmental program to strategically coordinates with state and local leaders to ensure
qualified workers to adopt technologies and best practices of energy efficiency and the renewable
energy ( DOE website, 2016). This investment, coupled with increased demand and new energy
standards has helped to make energy efficiency upgrades more accessible in some communities.
Motivation of homeowners to increase adoptions of energy audits 2.5
A summary of the reasons and motivations that homeowners would like to adopt the
energy improvements for their home are provided in Figure 2.4 and Figure 2.5 (Palmer, 2013).
23
Figure 2.4 shows that the reasons homeowners make home improvements, which are mainly
related to saving on utility (72%), low cost of investments (67%), benefits as safety and comfort (
57%), affordable cost (47%), easy installation ( 41%), and increase green value (18%) and
property value (14%).
Figure 2.4.Reasons homeowners make home improvements
(Palmer K. 2013)
Figure 2.5.Motivators to increase adoption of home energy
efficiency improvements (Palmer K. 2013)
24
Figure 2.5 shows that the motivations to adopt energy improvements. These include
energy cost, governmental rebate and subside, better understanding of audit, better access to
finances, better options for improving energy efficiency and less uncertainty in cost saving from
investments.
Figures 2.4 and 2.5, homeowners reveal high interests in the adoption of energy retrofits
by homeowners when they have better access to implement energy improvements (overcome
information barriers), when financing is available (overcome financial barriers) and less
uncertainty in their energy efficiency investments (overcome trust barriers). The major barriers
and the motivators that encourage homeowners action in adopting energy retrofits provides a
point of departure for this research, which centers on overcoming these barriers by improving
efficiency of energy audit process with an investigation of trust relationships between
homeowners and auditors.
Strategies in response to the challenges of home energy audits 2.6
The BPI and the NELC energy audit have developed strategies in respond to the critical
barriers of home energy audits. Table 2.3 summarizes the key strategies of BPI and the NELC to
overcome the critical barriers, as well as the comparison of strategies between BPI audit and the
NELC energy assessment
25
Table 2.3 Strategies of the BPI and the NELC energy audit in response to critical barriers of home energy audits (Wu and Riley, 2015)
Critical barriers and difficulties to adopt audits
Key strategies of BPI Home Energy Audit Key strategies of NELC Home Energy Audit
Homeowners rarely take time for home audits and also rarely implement improvements recommended in an audit
1. A BPI audit takes 2-4 hours to complete a in house walkthrough
2. Comprehensive inspection of whole house in details with blower door test, IR camera screen
3. Detailed report with savings estimates and recommendations of for home improvement
1. The NELC audit takes 1.5 hours to complete a value- oriented in-house walkthrough
2. Provides recommendations for improvements based on homeowner’s preferences and feasibility of implementation.
Homeowners cannot afford the upgrades that are recommended
4. Use detailed analysis to estimate savings that can be observed
5. Focus recommendations on improvements that have a high return on investment.
3. Focus on recommendations that homeowners are likely to pursue based on priorities, preferences cost, health and safety. Mix recommendations with health and safety issues and appeal to world view.
Homeowners lack of understanding about the information audits provide
6. Most of auditors communicate with engineering language and knowledge, which hard for homeowners to understand
4. Auditors are trained to communicate with homeowners with understandable skills and behaviors. Links to additional information and support are included.
Homeowners lack awareness of audits and home energy systems
7. Seek to educate homeowners as a side element of audit process and as a part of energy services business development
5. Inform and empower homeowners through survey of current awareness, custom reports, and linkage additional forms of assistance
A lack of trust in the reliability and accuracy of audit
8. BPI audit focuses on one- time sale of energy efficiency services
6. Provide 3rd party advice that seeks to initiate a long term relationship
26
Value Dimensions of Home Energy Audits 2.7
The first step in exploring the dimensions of value and trust in a home energy audit is to
identify the specific types and forms of value and trust related to home energy auditing processes.
“Value refers to any aspect of a potential product that could influence the likelihood that
customers would purchase that product” (Ralph L. Keeney, 2004). Thus, in the exchange of
“value” within homeowner-auditor relationships, the value of an energy auditor is defined heavily
by the level of trust the homeowner has built in with the recommendation of the auditor has
provided.
Different industries have unique definitions of “value”. Womack (Womack, 1996)
defines value as: “a capability provided to a customer at the right time at an appropriate price, as
defined in each case by the customer.” Neep (Neap & Celik, 1999) also defined value as the “fair
equivalent in service or commodities that an owner/buyer receives in exchange for money.”
To categorize value, this research adopts the value definition cited by John Kelly (Kelly,
Male, & Graham, 2004) in the book “Value Management of Construction Projects”. Kelly states
that value can be categorized as one of two kinds of value: “objective value” and “subjective
value”. Objective value refers to a measure of the input resources used to create a physical
component, object, or service, such as units of cost, mechanical-related effort, information and
resources. Examples of objective value creation in a home energy audit include the gathering and
exchange of information about the conditions within a home and the priorities of homeowners.
Subjective value refers to the desire to obtain or retain an item, or how much the owners/buyers
are prepared to pay for prestige, appearance, aesthetic, judicial, religious or moral reasons (Neap
& Celik, 1999). In a home energy audit, subjective value may take the form of the trust
27
developed between the homeowners and the service provider, and is created through the means
and methods used delivering an audit. Subjective value is strongly related to service providers’
personalities and delivery style, such as the approach to communicating with homeowners, how
well issues are explained, and the demonstration of respect.
Trust attributes informing the creation of a value-trust framework 2.8
In 1993, Construction Industry Institute (CII) presented findings from a study of the
relationship between cost and trust on construction projects. The study identified two types of
cost associated with trust. One type resulted from a consequence of mistrust. The other was
linked to cost-saving opportunities created as a result of trust. The real value associated with
cost/trust relationship is immeasurable. To extend this study, Hartman developed an architecture
to develop, maintain, or lose trust in contracting partnerships (Hartman, 2003). The trust model
evolved three distinct types of trust: Competence (Can you do the work well?), Integrity (Do I
trust you to consistently look after my interest?), and Intuitive (Does this feel right?). Hartman
also identified fourteen factors to measure the trust level in contracting partnership (Wong &
Cheung, 2004).
Various types of trust attributes have been characterized and adopted in different
industries (Coulter, 2002, Kahel, 1988, Wong, 2004). This research has adopted seven
characterized trust attributes (Competence, Customization, Reliability, Promptness, Similarity,
Politeness and Empathy) from service marketing research (Coulter, 2002) to respond to the
existing barriers in the energy audit environment. The characteristic of these seven trust
attributes are used to measure the relationship between trust performances and the target audit
outcomes including key questions: (1) how much does the homeowner trust the audit team and
28
the recommendations? And (2) what is the likelihood that homeowners will act upon
recommendations?
The research approach treats the energy audit as a technical service and proposes to
investigate value-trust exchange in the energy audit process quantitatively. Owing to the
similarity between the service industry and the energy audit process, eight trust attributes are
chosen from the service industry as a theoretical foundation for this research. Table 2.3 illustrates
the corresponded reasons for selecting these trust attributes applying in home energy audit from
previous researches. Column 1 lists the existing issues of home energy audit from Palmer’s
research (Palmer, 2013). Column 2, lists the seven selected trust attributes and column 3 lists the
trust treatments from research of service market (Coulter, 2002 & Kahel, 1988) and research of
construction industry ( Wong, 2004). Seven trust attributes are defined based on how they can be
applied to develop trust during the home energy audit process: “Competence”, “Customization”,
“ Reliability”, “ Promptness”, “ Similarity”, “Empathy” and “ Politeness”. Trust attribute
“Competence” refers to technical capabilities to indicate feasible investments for saving utility
usage. “Customization” refers to provide solutions based on homeowners’ unique conditions,
“Reliability” refers to the provision of solid information from governmental resources or evidence
of home issues to draw homeowners’ attention to potential saving. “Promptness” refers to
provide efficient and sufficient respond to homeowner during in-house audit. “Similarity” refers
to create an environment for homeowners receiving understanding and being heard, and
“Empathy” and “Politeness” refers to ensure respectful and appreciative interactions with
homeowners.
In addition to the seven trust attributes in literature, communication plays an important
role in an audit process to exchange information and building trust relationships during a home
29
energy audit. Most of the homeowners are challenged to understand all the information provided
by auditors (Palmer, 2013). Non-technical conversations and translation of energy systems
interactions are needed to smooth and improve communication in the auditing process. As such,
an additional attribute of “Open and Effective Communication” is added as the eighth trust
attribute in this research to address the need for communicative information between energy
auditors and homeowners (Wu & Riley, 2015).
30
Table 2.4. Trust attributes identified from research to respond to existing barriers of home energy improvements
(1) Existing issues
(Palmer, Walls, Gordon, & Gerarden, 2013)
(2) Trust attributes
(Coulter & Coulter, 2002)
(3) Treatments from the value-trust aspect
Wong (Wong & Cheung, 2004) Kahle (Kahle & Kennedy, 1988)
Low cost improvement
High saving on utility bills Competence
Competence of work
Alignment of effort and rewards ( alignment)
Better options for home energy efficiency
Improvement provides other benefits : comfort/safety/health
Installation is convenient
Customization Problem solving
Less uncertainty in cost saving from energy efficiency
Reliability Reputation
Long- term relationships
Promptness Effective and sufficient information flow (
information flow )
Similarity Compatibility; The sense of unity (unity) Sense of belonging
Empathy Politeness
respect and appreciation of the system ( respect )
Warm relationships with others Being well respected
Self - respect
Self- Fulfillment
A sense of accomplishment
Better understanding *Open and effective communication
Openness and integrity of communication ( openness )
Frequency and effectiveness of communication ( communication
*Added trust attribute by author
31
Characterizing Trust Attributes 2.9
To connect trust to value, the selected eight trust attributes are further categorized into
groups of “Objective Value” and “Subjective Value”. In this research, objective value is
considered to be a measure of information exchange related to home energy audit, such as audit
inspections, recommendations and solutions of energy improvement. The auditing processes
related in objective value are identified by trust attributes: “Competence”, “Customization”,
“Reliability” and “Promptness”. Subjective value refers to the measurement of trust relationship
resulting from interactions between homeowners and auditors. The interactions related to
subjective value are identified by trust attributes: “Similarity”, “Politeness”, “Empathy” and
“Open and effective communication”. The eight trust attributes are presented as follows to test
activities of in-house audit:
Objective value:
Competence: test the degree to which homeowners perceive that the auditors
possess the required skills and knowledge to supply the basic service.
Customization: test the auditors’ ability and/or willingness to adjust the service to
suit the homeowners’ needs.
Reliability: test the professional delivery of the inspection service.
Promptness: test the delivery of the service in a timely manner.
Subjective value:
Empathy: test the degree to which the auditors possess a warm, considerate and
caring attitude during the walkthrough.
32
Similarity: test the degree to which a homeowner perceives himself/herself to be
similar to the auditors, based on factors such as comparable tastes, preferences,
appearance, and lifestyle.
Politeness: test the degree to which the auditors are perceived as being
considerate, tactful, deferent and courteous.
Open and Effective Communication: test whether there was sufficient
information flow and transparency on the part of the auditors.
Chapter Summary and Research Approach 2.10
This chapter contains two sections; the first section presents existing background of home
audit market and barriers of adopting energy improvements for residential houses, and the
comparison of strategies of BPI audit and the NELC home energy audit in response to the
existing barriers.
The second section states the literature reviews of value dimensions and trust attributes
from service industry in respond to existing issues of home energy audit. Trust attributes are
selected regards to characterize trust attribute in respond to measuring activities of in-house
walkthrough, which provides a foundation for developing framework to assess value-trust
exchange of energy audit quantitatively.
The nature of this research will engage the survey methods to evaluate the home energy
audit process and method of observation to identify and classify value-trust exchanges as they
take place during an actual home energy assessment. Due to the challenges associated with both
collections of survey responses and observations of audit processes, multiple methods are applied
33
to gather data with an emphasis on the design of data collection in a manner that is integrated into
the audit process. For example, the post-audit survey of homeowners will be designed in a
manner that is both informative for homeowners and that informs the design of a continuous
improvement process for the NELC program. The observation and coding of audits will be
performed in a manner that can be replicated, and that could be used to provide feedback to an
audit trainee or professional. Detailed descriptions and rationale for the research methods and
techniques for data collection and analysis are explained more thoroughly in the following
chapters
34
Chapter 3
Methodology
Chapter 3 develops a framework to investigate the relationships between value-trust
exchanges and outcomes in the home energy audit process. The research problem statement and
objectives are defined based on the results of literature review and current practice. The
foundations of the research approach provided by Lean principles are introduced to explain
principles of value-trust exchange. The characteristic of effort, value and waste is presented as the
initial method to create a systematic framework of measuring trust attributes during an in-house
audit. A series of value-trust exchange models are presented as the basis of the research data
collection. Finally, the characteristics of trust attributes are defined for the development of a
survey and statistical analysis.
Research Goal 3.1
Information, financing, available workforce, and trust are indicated as major barriers to
the implementation of energy improvements by homeowners in the wake of home energy audits
(Palmer, 2013). This research proposes to further define value transactions in the home energy
audit processes while seeking to overcome barriers to the advancement of home energy efficiency
in single family homes. The research process includes the design of a framework that enables
evaluation of value-trust exchange qualitatively and quantitatively. This framework is then used
35
to study the relationships between value-trust delivery methods and the audit impact on
homeowners’ intention to implement energy improvements.
3.1.1 Research Objectives
This research seeks to examine the home energy audit process from a standpoint of value-
trust exchange. To achieve the research goal, the following objectives are pursued with the
architecture presented in Figure 3.1:
1. Conduct literature review to study background of home energy audit research and
industry practices with a focus on the comparison of existing auditing methods.
Study characteristics and deliver methods of value dimensions and trust attributes
and the key indicators of value-trust exchange in home energy audit.
2. Develop a survey instrument to evaluate audit process and the trust attributes,
constraints and homeowner characteristics that may influence homeowners’
intention to implement energy improvements. In addition, develop a coding
instrument to examine audit recordings designed to identify and classify value-
trust exchange during the audit process in the manner of time.
3. Construct a series of value-trust models for statistical analysis that enable the
study of relationships between variables of audit process and the homeowners’
overall self-identified trust level in the energy audit and influences on
homeowners’ intentions to implement energy improvements.
36
4. Evaluate results and identify critical interactions that encourage homeowners to
act upon energy improvements and implications of these results on the design of
home energy audit program and process design.
37
Figure 3.1. Research flow illustrates the architecture of the research processes and
objectives in each chapter
Develop methods for data collection and analysis
Interpret the statistical results from survey data and
coding.
Cross compare the key variables and critical
interactions that encourage homeowners’ action to
energy improvements.
Perform Literature
Review and
Theoretical
Background
Chapter 2
Develop Value/ Trust
exchange model, value/
trust matrix and
coding instrument
Chapter 3, 4, 5
Data collection and
Interpret the statistical
results and coding
finding
Chapter 6, 7
Conduct literature review and identify research scope
Identify the key indicators for value-trust exchange in
home energy audit
Survey design with
value/ trust matrix
Construct coding
instrument for
identifying value/
trust exchange in an
NELC in-house audit
Define research questions and research variables
• Construct analysis
model and model
computation to
measure the value-
trust exchange in
energy audit.
Compare home energy
audit methods and
identify pros and cons
Study energy audit
background and
existing problems.
38
3.1.2 Research Approach
In this research, a home energy audit is treated as a production process which contains
both operational (technical characteristics) and intellectual (service characteristics) tasks in a
service process. The research applies the research methodology of “case study method of
observation” combined with “survey investigation”. The former helps to examine the
characteristics of a particular process and defines the environment in which the research takes
place. The latter is used to collect overall feedback on the audit service and the homeowners’
intentions to implement energy improvements. The exploratory nature of this research is intended
to explore and explain the home energy audit value-trust exchange and the development and
testing of a systematic value-trust evaluation of home energy audits.
The research approach involves identifying value dimensions, trust attributes, classifying
time spent on the numbers of zones of house during an in-house audit and the customization of
the energy audit report with priorities of recommendations and levels of cost investments. The
house zones include exterior walkthrough, interior walkthrough, basement (mechanical room) and
attic.
Lean perspective of value exchange 3.2
The concept of Lean is demonstrated in the working philosophy and practice in the
Toyota Production System (TPS), which focuses on continuous improvement and tools and
methods to improve process efficiency (Womack, J. P. (2006). Lean methods seek to generate
value through the elimination of waste and continuing improvements. Womack and Jones (1996)
defined five main principles of lean thinking:
39
1. Specify value – define the value requested from the end customer, the product
engages a specific capability presented at a specific time.
2. Identify value stream – identify the value stream of the entire product task or
product families as well as the waste that can be eliminated.
3. Make value flow – ensure the remaining tasks are creating value and driving the
next step flow.
4. Let the customer pull value – products are precisely designed and meet the
customers’ requirements.
5. Pursue perfection – defects are a type of waste, ensure perfection of product and
service ensure success as outcome.
Lean thinking has the potential to inform new methods for home energy audit practices.
This research approach seeks to embrace multiple forms of value exchange including: (1)
understanding and incorporating homeowners’ preferences, concerns, and priorities, (2)
identifying and utilizing value dimensions and trust attributes during the audit practices, (3)
providing recommendations that are targeted to unique conditions in each home from the
perspective as a third party, and (4) improving how time is invested in data collection to
maximize value and reduce waste.
Effort and Value 3.3
When considering value in a home energy audit, it is worthwhile to consider the effort
invested in an audit and the initial concept of audit efficiency. As described in Lean principles,
the goal of an audit should be to maximize value adding processes while also expending the
40
minimal effort to be needed to enable these processes. “Value adding processes” refers to
generating continual improvements occur as an ongoing value creation for stakeholders, (Sanford,
2011), including users, co-creators, the environment, community, and investors. “Effort” is
introduced as an investment that can be measured in a variety of ways, such as time and money.
In the case of this research, effort is measured in time, specifically time spent during the home
energy audit. Total audit effort expended includes all of the time spent by auditors on the physical
home energy audit, which is expected to be approximately 90 minutes in the NELC program.
It is inevitable that only some of this time and effort contributes to the generation of value
adding processes, and that some of this time is wasted, such as time spent waiting or looking for a
misplaced tool. There is also time spent on necessary but non-value adding activities, such as
travel time between zones of a home. The first step of research is to categorize (a) Valuable
effort, (b) No-value, but necessary effort and (c). Waste. The categorization of effort in time
invested into a home energy audit systematically elevates the benefits of customization of the
audit process for homeowners individually and highlights value exchange in the inspection
system. The elimination of waste effort spent on unnecessary tasks is also more feasible. For
example, an assessor should spend more time on homeowners’ concerns instead of recently
installed equipment. Also, the auditor should provide recommendations that meet homeowners’
preferences and that are feasible, increasing the chance of implementation. Equation 3.1 is created
to express the transformation from Effort in time to value adding effort, non-value effort and
wasted effort.
Teffort = Veffort + NVeffort + Weffort 3.1
41
where
Total effort (Teffort) = time spent on audit (minutes)
Value adding effort (Veffort) = time spent or invested on the generation of value (minutes)
Non-value effort (NVeffort)= time spent on necessary but non-value adding activities (minutes)
Wasted effort (Weffort)= time spent on unnecessary and non-value adding activities (minutes)
Building on this foundation, the concept of audit efficiency is introduced as useful metric
that can be described as Equation 3.2 below.
Audit Efficiency =Veffort
Teffort⁄ (in a manner of time-minutes) 3.2
While audit efficiency can be calculated through the use of time, the variability of value
adding processes with respect to their contribution to action on the part of homeowners is
significant and often unmeasurable. This research emphasizes the development of improved
understanding of value dimensions and value adding processes as an approach to improving the
design of home audit processes and practices.
Figure 3.1 illustrates the integrated concepts of invested value in an audit, objectives of
value of home energy audit, and value dimension as an initial framework of value model. Terms
of value of exchange (Vexchange) and value of trust (Vtrust) are introduced to define the objectives of
the audit with its associated value dimensions. In layers of value categories in a home energy
audit including invested effort categories of value adding effort (Veffort), non-value effort
42
Dimensions of value
Objectives of value Invested effort in
an Audit
Veffort Vexchange Objective value
Vtrust Subjective value
(NVeffort), and wasted effort (Weffort), the objectives of value, and dimensions of value. Value
adding processes (Veffort) yields instances of value transitions (Vexchange or Vtrust).
Value adding processes in home energy audits take many forms, but can be classified
based on objectives of value and dimensions of value and the number of instances in which they
take place during an audit. Through observations of audits over time, categories of Vexchange, and
Vtrust are linked to a direct task or value transaction during an in-house energy audit. A deeper
exploration of the types of value adding processes that take place during audit and how they
contribute to the generation of trust is presented as Table 3.1. Table 3.1 presents two examples of
value adding processes that can be uniquely identified with corresponding descriptions of how
value is generated, and the categorization of objectives of value (Vexchange or Vtrust) and dimensions
of value (subjective or objective).
NVeffort
Weffort
Figure 3.2 Initial framework of value model: Layers of value types
in the home energy audit.
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Table 3.1: Examples of effort contributed to value adding processes and the
corresponded value dimensions and objectives of value
Example of value adding
process identified in an
audit
Descriptions of how value is
generated
Objectives
of Value
Dimension of
value
Identify envelope
penetrations that are in
need of air sealing
Penetrations which result in a
large (amount) percent of
unwanted heat gain/loss are
detected and can be addressed
through air tightening measures
V exchange Objective
Demonstrate active
listening to homeowner
by repeating and directly
responding to information
they have shared
Demonstration of listening and
responsiveness to homeowners
helps to build trust relationships
V trust Subjective
Value- Trust Model 3.4
Different approaches are used to measure objective and subjective value in this research.
The measurement of objective value mainly focuses on auditors’ capability to detect technical
issues and provide information to solve problems related to energy efficiency, while, the
measurement of subjective value mainly focuses on emotional interactions to make homeowners
feel comfortable to receive information. In addition, a detailed matrix of trust attributes are
introduced to measure the service-level performance with regard to implementations of energy
improvements. This includes homeowners’ perception of trust attributes and homeowners’
intention to implement energy improvements.
Trust attributes are added to evaluate value transitions in details with task instances.
Discreet inspection tasks are firstly classified based on the value dimensions: objective and
44
subjective value. when the objective value categorized trust attributes(Competence,
Customization, Reliability and Promptness) are used to demonstrate the value of inspecting house
and gathering information of home conditions (Vexchange), and the subjective value categorized
trust attributes (Similarity, Empathy, Politeness and Open and efficient communication) are
mainly focused on building trust relationship with homeowners through addressing homeowners’
concerns, priority and preference (Vtrust).
The objective value is evaluated in terms of trust attributes that are identified through
house inspection and data collection. This effort mainly focuses on various home systems such
as: attic, appliances, cooling, heating, lighting, renewable energy, water heating, building
envelope, and living upgrades. Subjective value is used to deliver the value in a manner
compliment, seeking permission, asking about homeowners’ concerns, and providing
explanation/ comments. Figure 3.3 demonstrates the trust-value exchange model, which
categorizes tasks of an audit walkthrough with corresponded value dimensions and trust
attributes.
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Figure 3.3. Trust- value exchange model - the categorized tasks of an assessment walkthrough with corresponded trust attributes and
value dimension.( Wu & Riley, 2015)
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Approaches to Measure Value-Trust Exchange 3.5
Two research methods are used to assess the value-trust performance during the in-house
walkthrough: (1) Post-audit survey and (2) audio recording analysis of in-house audit
walkthrough. The post-audit survey focuses on homeowners’ overall experience with the auditors
during an in-house walkthrough. It is administered after homeowners receive their energy report
with customized recommendations for energy improvements. The audio recording focuses on the
measurements of time spent on interacting with homeowners and the corresponding value-trust
types, as well as how much time spending on different zones of house areas.
The survey and audit recording are used to identify targeted value dimension and trust
attributes in an in-house audit. Each strategy is defined simultaneously to measure trust attribute
presented as recording analysis and surveys. For example, in the recording analysis, the
subjective value, “Empathy”, refers to the “The auditor possesses a warm considerate and caring
attitude at appropriate times to help homeowners feel more comfortable” (Kahle & McAllister,
1995). The trust attribute of empathy is indicated if the homeowner felt that the energy audit team
was “caring”, “warm” and “friendly” to homeowners in the survey. Another example of objective
value in the recording analysis, “Competence”, refers to “Auditor possesses the required skills
and knowledge to supply the basic inspection to home, technical information to energy
efficiency”, whereas the competence is indicated if the energy audit team was “well-trained?”,
“being knowledgeable? ” and “ being an expert in his/her field?”.
Table 3.3 demonstrates the trust behaviors and survey questions applicable to both audit
recording coding and post-audit surveys. (Coulter, 2001, Wong & Cheung ,2004, Kahle &
McAllister, 1995, Zaghloul, & Hartman, 2002). Column 1 illustrates the trust behaviors during
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energy audit which can be addressed as the corresponded types of trust attributes. Column 2
addresses eight types of trust attributes this research focuses on detecting during auditing.
Column 3 illustrates the methods and styles of questions corresponded to trust attributes
addressed in the survey.
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Table 3.2 Summary table of trust attributes and trust behaviors
Behaviors observed during auditing as types of trust
(1)
Trust Attributes
(2)
Survey Questions:
The energy audit team:
(3)
Homeowner perceives himself/herself to be similar to the auditors, such as comparable tastes, preferences, appearance, lifestyle, culture and value standard.
Similarity
Has values and beliefs similar to mine?
Has tastes and preference similar to mine?
Is quite a bit like me?
The auditor possesses a “warm and caring" attitude at appropriate time to make homeowners feeling more comfortable.
Empathy
Is caring?
Is warm?
Is friendly?
The auditor is perceived as being considerate, tactful, deferent, courteous.
Politeness
Is polite?
Treats me with respect?
Is courteous?
Effective and sufficient information flow that creates transparency in a relationship
*Open & Effective Communication
Is well spoken and communicated clearly?
Is able to share technical information in a way I understood?
Auditor possesses the required skills and knowledge to supply the basic inspection to home, technical information to energy efficiency.
Competence
Is an expert in his/her field?
Is extremely experienced in this business?
Auditor’s ability (or willingness) to vary the energy solutions, in order to suit the individual homeowner's needs.
Ability to Customize solutions
Provides me with well thought out alternatives suited to my unique need?
Respond to homeowner’s questions, concerns in a timely manner
Promptness Deals promptly with my needs?
Deals with me in a timely manner?
The delivery of that product/ service in an ethical, dependable manner
Reliability Provides promised service?
Is dependable?
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In addition to the instances related to trust attributes in the audit walkthrough, there are
additional factors that may influence homeowners’ intention to implement energy improvement.
Thus, the dependent variable, “Homeowners’ intention to implement energy improvement” is
aimed to be predicted by fixed effects for the internal scaled predictors, such as: eight trust
attributes, homeowners’ overall likelihood of in-house audit, homeowners’ confidence level to
take actions, implementation constraints and cost of energy improvements, shown as Figure 3.4.
More detailed description of the predictor design will be provided in Chapter 4.
Independent Variables Dependent Variables
Eight Trust attributes
Homeowners’ intention to implement energy improvement
o Similarity o Empathy o Politeness o Open & Effective
communication
o Competence o Customization o Reliability o Promptness
Likelihood of in-house audit
Confidence level to take action
Implementation constraints
Cost of energy improvements
Figure 3.4 The relationships between independent and dependent variables
Predict
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Chapter 4
Survey Design
Chapter 4 describes the development of a post-audit survey and the conversion of data for
statistical analysis. The purpose of this research survey is to identify the level of trust-value that
the homeowners derive from in-house audit processes. This value-trust exchange is highly
related to interactions between homeowners and auditors within a 90-120 minutes in-house
walkthrough. Student auditors trained by the NELC program are required to learn communication
skills and customized behavior to interact with homeowners to match their unique requirements
as well as deliver value processes. The post-audit survey is comprised of three sections: (a)
Homeowners’ confidence level to perform energy improvements, (b) Trust attributes accumulated
during an in-house walkthrough, and (c) the homeowners’ self-reported intentions to implement
energy improvements in an expected timeframe, including the factors affecting this intention,
such as information, financial and trust constraints. Each is described in more detail below:
Survey design – Homeowners’ confidence level 4.1
Homeowners’ confidence level to make energy improvements refer to homeowners’
self-assessed capability, skills and time to implement energy improvements of their homes.
Confidence levels are assessed on a scale that
Homeowners are confident he/she can make improvements themselves.
Homeowners are confident he/she will be able to find professional services needed
to make improvements.
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Homeowners are confident that he/she can afford to invest in improvements
Homeowners are confident that he/she has time to act on the improvements.
Four questions relating to homeowners’ confidence level to implement energy
improvements are asked in the post-audit survey after homeowners receiving their customized
energy audit report. These four statements are:
I am confident I can make improvements myself
I am confident that I have the time to made improvements made
I am confident I will be able to find professional services needed to make
improvements
I am confident that I can afford to invest in improvements
The statements are responded to with a 4 point scale to indicate strongly agree (4
points), agree (3 points), disagree (2 points), and strongly disagree (1 point).
Survey design – In-house walkthrough trust attributes 4.2
Trust attributes accumulated during an in-house walkthrough refers to audit interactions
related to eight trust attributes that enables audit of homeowner’s perception of the auditors’
process. The interactions with homeowners can be classified with specific measurements related
to the eight identified trust attributes of “Competence”, “Customization”, “Reliability”,
“Promptness”, “Similarity”, “Empathy”, “Politeness” and “Open and efficient communication”.
Individual questions in the survey are designed for each set of trust attributes. The 4 point Likert
scale is used instead of the 5 point Likert scale in this research to prevent neutral responses from
occurring in the survey responses, where 1 equals to “Strongly disagree”, 2 equals to “Disagree”,
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3 equals to “Agree” and 4 equals to “Strongly agree”. All responses are converted into the
corresponding scale before conducting statistical analysis.
The trust-attributes are used to evaluate subjective value, objective value, and the overall
trust relationship developed during the in-house walkthrough. Trust attributes of subjective value
refer to “Similarity”, “Empathy”, “Politeness” and “Open and effective communication”. Trust
attributes of objective value are referred as “Competence”, “Customization”, “Reliability” and
“Promptness”. Twenty questions are created to evaluate the homeowner’s perception of the
auditors’ performance related to eight defined trust-attributes. Fifteen questions relate to audit
process and the other five questions relate to report delivery. Multiple questions are asked to
investigate single trust attributes, the value of responses related to single trust attribute are
averaged to assess the relationship with the outcome as equation 4.1:
𝑉𝑧 =∑ survey responses of questions related to z types of trust attribute
number of questions related to z types of trust attribute 4.1
where
Z = types of trust attributes: Similarity, Empathy, Politeness, Open & Effective
communication, Competence, Customization, Reliability, and Promptness.
Table 4.1 illustrates the descriptions of the eight trust attributes and the justifications applied in
the post-audit survey.
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Table 4.1 Summary table of trust attributes and justified survey questions
Trust Attributes (1)
Question of Trust Attributes from literature review (2)
The service provider
Justification of Trust Attributes in
Survey (3):
The energy audit team
Similarity
Have values and beliefs similar to mine?
Has tastes and preference similar to mine?
Is quite a bit like me?
Was understanding of my concerns?
Was understanding of my interests/priorities?
Empathy
Is caring?
Is warm?
Is friendly?
Was warm and friendly?
Was judgmental about my home?
Politeness
Is polite?
Treats me with respect?
Is courteous?
Was polite?
Was respectful?
Was not pushy or rushing me?
*Open & Effective Communication
Was well spoken and communicated clearly?
Was able to share technical information in a way I understood?
The report is clear and understandable?
Competence
Is an expert in his/her field?
Is extremely experienced in this business?
Was well-trained?
Seemed knowledgeable?
The report provide and enough information or resources for the implementations
Ability to Customize solutions
Provides me with well thought out alternatives suited to my unique need?
Was flexible and responsive to my needs?
The report provides recommendations that meet my interest and preference?
The recommendations are feasible according to my unique conditions?
Promptness
Deals promptly with my needs?
Deals with me in a timely manner?
Arrive one time?
Completed the audit in a timely fashion?
The report is completed and delivered in a timely
Reliability Provides promised service?
Is dependable? Seems reliable?
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In addition to twenty detailed questions related to eight defined trust attributes, an overall
question is added for homeowner to self-evaluate “the overall trust level” homeowners perceived
after in-house audits. The statement is phrased as “Overall, I trust the work done by the audit
team and their recommendations” Homeowners are expected to respond with the 4 point Likert
scale as strongly agree (4 points), agree (3 points), disagree (2 points) and strongly disagree (1
point). Figure 4.1 summarizes the relationship between independent variables and the dependent
variables in this research.
Independent Variables Dependent Variables
Trust attributes
Likelihood of in-house audit
Intention to implement energy improvements ( in a liner time scale )
o Similarity o Empathy o Politeness o Open & Effective communication o Competence o Customization o Reliability o Promptness
Figure 4.1. The relationship between independent and dependent variables
Survey Design – Homeowners’ Intention to Implement Energy Improvements and 4.3
Practical Constraints
The intention to implement energy improvements refers homeowner’s self-reported
intention to take action on the top five recommendations in the report individually, which
includes sub-questions of practical constrains related to homeowners’ major concerns and
difficulties regarding taking action. Homeowners’ intention to each recommendation is designed
to be answered in a manner of time period to indicate “how soon the homeowner will commit to
action”. Four options of time periods, on a scale of 1-4 (4 = already done, 3 = will do in the next
Predict
55
three month, 2 = will do it in the next year and 1 = no plan to implement) are designed to measure
homeowners’ intention to implement energy improvements. Five sub-questions are included to
seek specific feedback on the reasons why or why not homeowners intend to pursue each
recommendation.
After completion of an in-house walkthrough, the homeowner received a customized
report with the recommended top five Energy Efficient Measurements (EEMs). These top five
recommendations are selected and prioritized based on the audit results, homeowners’ concerns,
preferences, and priorities. Along with each recommendation, five potential constraints on
implementations of energy improvements are listed to indicate the levels of difficulty to take
action. These constraints questions are stated as Table 4.2 with the corresponded predictors as
“Cost, “Return on investment”, “Affordable cost”, “Increase safety, health, and comfort” and
“Sufficient skills and information to energy improvements”. The 4 point Likert scale is also
applied to indicate homeowners’ concerns as strongly agree (4 points), agree (3 points), disagree
(2 points) and strongly disagree (1 point).
Table 4.2 Constraints and corresponding questions of energy improvements
Constraint
Questions of constraints on energy improvements
I believe the recommendation
Cost Will save me money on my utility bills
Return on investment Is a good investment that will pay for itself
Affordable cost Will cost more than I can afford
Increase Safety/ Health/
Comfort Will make my home safer, more healthy, and more comfortable
Information/ Skill Requires more investigation/ information
Information/ Skill Will be too complicated to take action
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Survey data computation 4.4
Many variables are listed above in the relationships between energy audit process and
homeowners’ intention to implement energy improvements. However, a homeowner’s intention
to implement energy improvements is a critical element of this research, and can be demonstrated
by various levels of intention based on how soon homeowners indicate they plan to implement
improvements. The timeframe homeowners are asked to state intentions is classified into four
periods that can be weighted to enable strong intentions to be valued greater than more uncertain,
long term intentions. To achieve this, the five recommendations (Top1~Top5) of energy
improvements are provided to homeowners in the report and linked to the survey a question
designed to indicate “When do you plan to implement this recommendation” in a scale of respond
options of “Already done (4)”, “Will do it in 3 months (3), “Will do it in a year (2)”, “No plan to
do it (0).
To compute the time period of implementation with an appropriative weight, a
mathematic formula is established with an assumption of maximum time to implement the
recommendations. The resulting value for the ith individual (where i=1, 2, 3, ... 46) is computed
as in Equation 4.2 as:
Viq =Nq−Xiq
Nq , 4.2
where
q = recommendation number, q = 1, 2, 3, 4, 5
Nq = assumed maximum time (sixty months) to implement the qth recommendation
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Xiq = required time for the qth implementation
The ith individual will have 5 recommendations, thus will get 5 values (Vi1, Vi2, Vi3,
Vi4, Vi5) for 5 periods of time to implement the qth implementations, Xi1, Xi2, Xi3, Xi4, Xi5:
Xi1 → Vi1
Xi2 → Vi2
Xi3 → Vi3
Xi4 → Vi4
Xi5 → Vi5
The maximum time period for a homeowner to implement energy improvements are
assumed into 5 years (60 months), 3 year (36 months) and 1.5 years (18 months) based on the
practical experience of audit ( NELC, 2013). Homeowners are asked to predict how soon they
will take action of each recommendation in a scale of four (“already done (4)”, “will do it in the
next 3 month (3)”, “will do it in a year (2)”, “no plan to do it (1)”). Those four options of
responses were further converted into continuous weight by Equation 4.2 for the statistical
analysis. Table 4.3 illustrates the converted weight of survey option to implement energy
improvements.
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Table 4.3. Computation of weight of maximum time to implement energy improvements
Assumed maximum time to implement energy improvements
60 months 36 months 18 months
Converted weight of survey option to implement energy improvements.
V already done = 60−0
60 = 1
V 3months = 60−3
60 = 0.95
V 1 year = 60−12
60 = 0.8
V no plan = 60−60
60 = 0
V already done = 36−0
36 = 1
V 3months= 36−3
36= 0.9167
V 1 year = 36−12
36 = 0.667
V no plan = 36−36
36 = 0
V already done = 18 −0
18 = 1
V 3 months = 18−3
18 = 0.8333
V 1 year = 18−12
18 = 0.3333
V no plan = 18−18
18 = 0
Other Survey Design Variables 4.5
Besides trust attribute and practical constrains involved in an in-house audit, there are
other variables may also influence homeowners’ decision making to take action. Those variables
includes “cost of investments of energy improvements”, “homeowners’ gender” and “worldview”
that may also vary homeowners’ timeline to implement energy improvements. This section
describes how variables are defined in a systematic approach.
4.5.1 Classification of investment cost
Some investments in energy improvements are easy and low cost, such as upgrading light
bulbs, installing window blinds, while other energy improvements are complicated and
expensive, such as installing solar panel and replacing water heater. Various energy
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improvements are eligible to increase the energy efficiency in single houses. In order to match the
implement weight of each task systematically, energy improvements are classified into five
categories based on its investment cost in the current market: Group 1 (investment cost range
below $500), Group 2 (cost range between $501 and $1000), Group 3 (cost range between $1001
and $1500), Group 4 (cost range between $1501 and $3000) and Group 5 (cost range above
$3000).
Assuming a shorter time period is needed to implement cheaper and less complicated
tasks of energy improvement, the calculated weights of maximum time period to implement
energy improvements are applied as :
(1) Assumed maximum time to implement tasks in Group 1 and Group 2 is 18 months,
(2) Assumed maximum time to implement tasks in Group 3 and Group 4 is 3 years (36
months)
(3) Assumed maximum time to implement tasks in Group 5 is 5 years (60 months)
Table 4.4 illustrates examples of common tasks recommended in energy audit cases with
cost range, assumed maximum time to implement, and the corresponded weight.
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Table 4.4 Examples of common tasks recommended in our audit cases with its cost range,
assumed maximum time to implement it and the corresponded weight as following.
Cost range (USD)
Energy Improvements Assumed Time to
Complete Corresponded Weight
< 500
Upgrade Light bulbs
Upgrade programmable thermostat
Install window blinds
Weather strip door and window
Seal and insulate air ducts
Service Geothermal heat pump
Clean duct and vents
18 months
Already done = 1
Do it in 3 months = 0.95
Do it in a year = 0.8
No plan to do it = 0
501 -1000 Install attic fan
Install a door 18 months
1001 -1500
Add home energy management
Install basement ceiling
Blow-in wall insulation
Attic insulation
Upgrade dishwasher or washing machine
3 years Already done = 1
Do it in 3 months = 0.9167
Do it in a year = 0.667
No plan to do it = 0
1501-3000
Install refrigerator
Install hot water heather
Install electric blinds
Install mini split AC
Air seal exterior
3 years
>3000
Install solar panels
Install a heat pump
Install a whole house fan
Upgrade windows
Upgrade siding
5 years
Already done = 1
Do it in 3 months = 0.8333
Do it in a year = 0.3333
No plan to do it = 0
* Market cost of energy improvement reference: http://www.homeadvisor.com/cost/all-
categories/
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4.5.2 Worldview
Worldview refers to the study by the Shelton Group (2013) in which distinct market
segments of home energy clients are categorized (in percentage of home energy clients) into four
types (% of population): True believer (23.5%), Cautious Conservatives (22%), Concerned
Parents (31%) and Working Class Realists (23.5%). Studying homeowners’ worldview highly
contributes to the mean and methods to communicate to homeowner while mitigating information
barriers. The NELC provides adequate support to translate homeowners’ awareness and
motivation into energy improvement actions, and maintain their engagement (Sprehn, 2013) by
training auditors to recognize homeowners’ worldview as well as provide corresponding
interactions to homeowners’ worldview. For data analysis, homeowners’ worldview are
categorized as “Cautious Conservative = 1”, “Concerned Parents = 2”, “Working Class Realist =
3” and “True Believer = 4” for analysis in the mixed effects model with other variables. Table 4.5
illustrates intrinsic and extrinsic motivations of each type of worldview. (UtilityPulse program,
Shelton group, 2013).
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Table 4.5 Worldview†: Intrinsic and extrinsic motivations of each type of worldview
(UtilityPulse program, Shelton group, 2013).
Worldviews & characteristic and motivation and extrinsic qualities % of population
True Believers
Intrinsic – Protect environment live responsibility
Extrinsic – save money, rebates, payback/ ROI, social norms
23.5%
They're very driven by environmentalism and global-warming concerns
They're more likely than average to fall into the 35–44 age group
They’re consistent in their attitudes and actions. 91% of them rate energy conservation as
important or very important in their daily purchase decisions and habits, and 57% of them
(compared to 21% overall) fall into the highest energy-conservation activity category (7–23
activities).
Cautious Conservation
Extrinsic – saving money, control, resale value
22%
The largest numbers of them have adopted an average number of energy-saving products or
habits (41% are in the medium range).
They are knowledgeable about energy but not driven by environmental issues.
Their primary purchase drivers are saving money and getting more control over personal
energy consumption and costs.
Concerned Parents
Intrinsic – health and welfare of their family
Extrinsic – lower bills, payback/ ROI
31%
They are more likely than average to be aged 18–34.
Many (29%) are homemakers and 46% (vs. 41% overall) have children in the home.
They’re very driven by saving money and getting control over personal energy consumption
and costs, but believe conserving energy is important in the way it affects their daily purchase
choices and activities.
Working Class
Extrinsic – lower bills, payback/ ROI
23.5%
Most are single and younger than the overall population.
Many of them are blue-collar and unemployed workers
They have purchased very few energy-efficient products and have few conservation habits.
Chapter Summary 4.6
This chapter discussed the development process of the post-audit survey, and the
classifications of grouped variables designed to predict the impact on homeowners’
63
implementations of energy improvements. Questions are phrased and adjusted based on the
character of each attribute in a four level scale to prevent neutral resonances. Equations are used
to convert survey responses into continuous weight for the further statistical analysis.
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Chapter 5
Data Collection and Coding Instrument
A survey questionnaire was designed and distributed to homeowners who volunteered to
be part of the NELC energy audit program from the fall of 2012 to summer of 2015. Chapter 4
described the development of survey questionnaire. Chapter 5 illustrates the code instruments
used to classify value-trust transactions for the eight trust attributes in the audit recording. The
chapter describes methods of data collection and a coding instrument to clarify activities related
to trust attributes used in constructing the framework for data analysis.
Data collection methods 5.1
This research used both survey questionnaires and audio recordings of audit walkthrough
to collect homeowners’ feedback and observational data directly from the homeowners.
Questionnaires were distributed by email, postal mail, as well as administrated in person. Forty-
six out of forty-nine valid surveys were collected by the researchers. The recordings were made
during in-house audits with homeowners’ permission. Additionally, sixteen homeowners received
their energy report in the Morning Star home. This facility was designed to demonstrate energy
efficiency and renewable energy technologies to community members, and provided a setting for
homeowners to see some of the materials and technologies recommended for homes in the
northeast region of the U.S.
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65
Survey Data Demographic 5.2
The post-audit survey were sent out to homeowners via postal mails, emails or
administered in person after homeowners received the customized audit reports including the top
five recommendations of energy improvements. These top five recommendations have selected
based on audit results, homeowners’ concerns, preferences and feasibility of energy
improvements.
Forty-six surveys were collected from homeowners in State College (Penn State) and
nearby communities (Figure 5.1). Seventeen respondents were male and thirty-one respondents
were female (Figure 5.2). Figure 5.3 shows the distribution of surveys sent to each community on
a Pennsylvania map.
Figure 5.1. 48 survey respondents were collected from State College and nearby
communities
32
3 2 2 1 3
1 1 1 2
0
5
10
15
20
25
30
35
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66
Figure 5.2.Survey response rate by gender
Numbers of survey delivered to communities in Pennsylvania regions
Figure 5.3.Numbers of surveys sent to communities near State College
Recording and coding of audits was performed for thirty in-house audits that in the State
College region. Table 5.4 presents the average size of these 30 houses is 1,965 square feet,
average estimated house market price in December 2015 was $ 276,938 and the average numbers
of bedroom and bathrooms are 3.46 and 2.05 units per house. The smallest size of house is 1,248
sqft and the biggest size of house is 3,265 sqft.
17
31
0%
20%
40%
60%
80%
Male Female
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Table 5.1 Information on the 30 audited houses (Source: www.zillow.com)
Floor area
(square feet)
Estimated market
price (USD) Bedrooms Bathrooms
Average Value 1965 $276,938 3.46 2.05
Audit Recording Demographic 5.3
Thirty audits were recorded for the analysis. Twenty-two home energy audits were
recorded in the State College community, while two were recorded in Bellefonte, two in West
Decatur, two in Boalsburg, one in Tyrone, and one in Howard. These audit recordings were
coded according to the coding instrument (Appendix A) for further analysis.
It is important to recognize that the post audit survey was administered in highly variable
forms and in variable timeframes after the assessment. This variability limits some of
conclusions that can be drawn from the data, but can also be used to inform the design of future
processes to administer the survey. Measures taken to assess the impact of this variability on the
response rates and data are described in Chapter 6.
Frequency of Response 5.4
Post audit surveys were received in person or by mail/email after homeowners received
their home energy reports. The response rate of the survey questions are generally high, as
homeowners were willing to provide feedback on their energy auditing experience for this
research for the same reasons they agreed to the in-home audit by student teams. Table 5.2
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68
presents a summary of data obtained from the post-audit survey. Response rate of data are
received directly from survey response, except the data of cost category and homeowners’
characteristic. Cost categories of investment are defined based on the cost of the energy
efficiency measurement (EEMs) recommended with the reference of current market price range
(Homeadvisor, 2015). The data of homeowners’ characteristics are observed directly by trained
auditors during interactions. The types of variables included in the survey are listed, as well as
the distribution of response rate for the sample (N = 46 valid surveys).
Table 5.2 Response rate of grouped variables
Grouping Variables Response rate
Trust attributes
Competence, Customization, Reliability, Promptness, Similarity, Politeness, Empathy Open & Effective Communication
97.8 % 97.8 % 100% 100% 100% 100% 100% 100%
Trust level of home energy audit 97.8%
Cost categories of recommendations
Total
> $500 $500 ~ $1000 $1000 ~ $1500 $1500 ~ $3000 > $3000
96.5%
47.8% 7% 23% 10% 8.7 %
Constraints on making energy improvements
Save on utility bills Return of investment Affordable cost Safety/ health/ comfort, Information/ skill
96.5% 95.2% 92.1% 95.6% 96%
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69
Homeowners’ characteristics:
Gender (total)
Male Female
Worldview (total) Cautious Conservative Concerned Parents Working Class Realist True Believer
37% 63%
89.1% 47.8% 13% 13% 15.2%
The program received high satisfaction of energy auditing and report delivery from most
of the homeowners, which reveals high response rate (nearly 100%) on variables of trust category
(trust attributes, overall trust level of energy audit). However, the questions related to cost and
practical constraints on making energy improvements, some homeowners’ present uncertainty of
responses may be due to their unique conditions. On the other hand, the identification of
worldview of each homeowner was done by trained auditors, a relatively lower rate (89.1%) of
homeowners’ worldview is because that limited characteristics were observed for auditors to
identify homeowners’ worldview with a strong level of confidence.
Correlations of trust attributes 5.5
A correlation analysis was initially used to identify preliminary trust attributes from the
respondents to the survey questionnaire. Twenty audit-performance-related questions were
designed based on the eight selected trust attributes for homeowners to evaluate the in-house
walkthrough in the options of strongly agree (4), agree (3), disagree (2) and strongly disagree (1).
Table 5.3 presents the Spearman correlation size-to-measure correlations among trust variables
from a sample size of 46 valid responses.
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Table 5.3 Spearman Correlation between trust variable during the in-house audit
Correlations- Spearman's rho
1 2 3 4 5 6 7 8
1.Competence 1.000 .728**
.581**
.635**
.771**
.679**
.359* .831
**
2.Customization .728**
1.000 .589**
.745**
.714**
.651**
.341* .798
**
3.Reliability .581**
.589**
1.000 .674**
.690**
.861**
.259 .658**
4.Promptness .635**
.745**
.674**
1.000 .631**
.711**
.374* .757
**
5.Similarity .771**
.714**
.690**
.631**
1.000 .767**
.478**
.857**
6.Politeness .679**
.651**
.861**
.711**
.767**
1.000 .393**
.748**
7.Empathy .359* .341
* .259 .374
* .478
** .393
** 1.000 .410
**
8.O_E
Communication .831
** .798
** .658
** .757
** .857
** .748
** .410
** 1.000
**. Correlation is significant at the 0.01 level, *. significant at the 0.05 level
Bold indicates the correlations size range between 0.7 to 1.0
Preliminary results indicated significant correlations were observed among the trust
variables. Cohen’s (1998) guidelines were used to for interpreting the effect size of correlations.
Correlation size guidelines for the social sciences are as follows: weak (0.0 to 0.29; -0.29 to 0.0),
Moderate (0.30 to 0.49; -0.49 to -0.30) and Strong (0.50- 1.0; -1.0 to -0.5) (Cohen, 1988). Owing
to the strong correlations between selected trust variables, the research focuses on the correlation
size range of 0.7 to 1.0 (bold) to highlight internal correlation among trust attributes during home
energy audit. The initial findings of the trust performance in this correlation tables suggest
opportunities to strengthen homeowners’ satisfaction and motivation to energy improvements.
The initial interpretations are addressed in the following highlights:
Higher rating of “Competence” suggests expectations that auditors possess the
required skills and knowledge to supply the energy audit; they are expected to
customize solutions to homeowners’ unique conditions (Customization, 0.728), as
well as understanding homeowners’ interests or desires (Similarity, 0.771).
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Higher rating of “Customization” suggests that homeowners expect to have an
auditing experience that can help solving energy issues on time (Promptness, 0.745)
and delivered in a manner that are similar to expectations (Similarity, 0.714).
Higher rating of “Reliability” suggests that homeowners expect to have reliable
information provided in a polite, respectful manner (Politeness, 0.861) similar to their
expectations (Similarity, 0.690).
Higher correlations between Politeness and Promptness (Promptness, 0.711) and
Similarity (Similarity, 0.767) indicate expectations that homeowner will receive a
combination of respectful and on-time service delivered in a manner expected.
Higher rating of “Open and Effective communication” (O/E Comm), suggests that
auditors’ communication is expected to be presented as a multi-value skill regarding
Competence (0.831), Customization (0.7981), Promptness (0.757), Similarity (0.857)
and Politeness (0.748). This multi-value performance greatly reveals the auditing
barrier regarding lack of information (2009 CEQ report).
Coding Instrument of Eight Trust Attributes 5.6
Multiple interactions and the unique conditions of each home make it challenging to
classify value exchanges systematically. This classification greatly relies on characterizing the
interactions and context of the audit process. The coding instrument focuses on identifying the
most prominent value-trust exchanges within the auditing process. Table 5.4 presents the criteria,
applied in the coding process, for coding interactions and conversation during the audit for each
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trust attribute. For each trust attribute, types of behavior, examples of conversation, and types of
value adding processes are described.
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Table 5.4. Criteria for coding interactions/ conversation during audit for each trust attribute.
Trust Attributes
(1)
Behaviors observed during auditing as types of trust
(2)
Key Actions/ Conversation to identify trust attributes
(3)
Example of VALUE ADDING process
(4)
Subjective Value - Build Trust relationship
Similarity
Homeowner perceives himself/herself to be similar to the auditors, such as comparable tastes, preferences, appearance, lifestyle, culture and value standard.
“My house has the same issues…”
“I support PSU football too”
“I came from the same (region) as you”
Share common interests with homeowners related to home improvement
Empathy
The auditor possesses a “warm and caring" attitude at appropriate time to make homeowners feeling more comfortable.
“We understand your situation……”
“Your concern is reasonable,”
Acknowledge and compliment homeowners' effort in improving homes
Politeness The auditor is perceived as being considerate, tactful, deferent, and courteous.
“Thank you for having us here”
“Your house is nice and comfortable”
“Please let us know if you want to keep some spaces private”
“Should we take off our shoes?”
Demonstrate understanding to homeowners’ concerns and conditions
Open & Effective Communication
Effective and sufficient information flow that creates transparency in a relationship.
The auditor actively brings up questions related to house condition. Such as “Do you have any concern about this (place) ?”
Demonstrate listening to homeowner by responding to info they shared
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Trust Attributes
(1)
Behaviors observed during auditing as types of trust
(2)
Key Actions/ Conversation to identify trust attributes
(3)
Example of Value adding process
(4)
Objective Value - Information exchange
Competence
Auditor possesses the required skills and knowledge to supply the basic inspection to home, technical information to energy efficiency.
The auditor provides inspections and feasible and professional solutions to improve the issues
Inspect doors and windows for possible air sealing weatherization
Ability to Customize solutions
Auditor’s ability (or willingness) to vary the energy solutions, in order to suit the individual homeowner's needs.
Auditors provide multiple applicable solutions to improve issue, and finalize the most feasible solution according to homeowners’ condition.
Provide multiple feasible EEM recommendations while detecting corresponding home issues.
Reliability The delivery of product and service in an ethical, dependable manner
An auditor provides professional information based on creditable resources, such as DOE, Energy Star websites…etc.
Auditors provide “evidence” to demonstrate their information or camera.
Inspect house conditions include image from IR camera
Promptness Respond to homeowner’s questions, concerns in a timely manner
Auditors reply to homeowner’s questions (immediately) with non-technical information related to the issues. Such as: “I see, we would like to study this question and replay to you later.”
Respond to homeowners' concerns and questions
Non-value activities
Waiting, transfer from one place to the other
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The subjective trust attributes emphasize non-technical conversations and interactions
between homeowners and auditors, which mainly enable the homeowners to perceive “being
understood,” “warm considerate,” “caring,” and “communicable” interactions with the auditors.
For example, the trust attribute Similarity addresses conversation/interactions that reveal how the
homeowner perceives similar tastes, preferences, lifestyles, cultures, or values of auditors.
Examples include sharing the same interests, backgrounds, or memories that might be irrelevant
to technical energy inspections, but that build trusting relationships. The trust attribute Empathy
signifies that a “warm and caring" attitude was expressed in a manner makes the homeowner(s)
feel more comfortable. The trust attribute Politeness is defined as “being considerate”, “tactful”
and “deferent” and is expressed by auditors being respectful of the setting in which they are
investigating someone’s home. Since the lack of information related to energy improvements
was viewed as one of the barriers and obstacles that prevented homeowners from taking action,
the attribute Open & Effective Communication is stated as delivering “effective and sufficient
information” that helps homeowners to understand the observations made during the audit, and
also in a way that is responsive to their questions.
The study of objective value attributes mainly focuses on identifying interactions that
correspond to audit inspection, technical information, and methods that utilize evidence to verify
energy issues. The trust attribute Competence is demonstrated as the required skill and/or
knowledge by auditors to conduct a basic inspection of the home. Auditors are expected to
provide technical capabilities to recognize energy efficiency issues of a home. The trust attribute
Customization refers to the auditors’ ability to vary the audit process based on their interactions,
and also to make recommendations in a way that is perceived as responsive to the unique
conditions and circumstances in each home. The trust attribute Reliability is defined as
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demonstrating methods to gather real evidence, such as utilizing the infrared camera to detect
flawed insulation in the building envelope, such as walls, ceilings, and windows for air leakages
or penetrations. Reliability can also be demonstrated by providing credible and useful information
from resources such as the Department of Energy. Reliability can also be demonstrated by an
auditor doing what they said they would do, in terms of arriving at a certain time, taking the time
to complete the audit on time, and presenting the report in the timeframe promised. The trust
attribute Promptness refers to auditors arriving for the audit and also responding to the
homeowner’s questions or concerns in a timely manner. To differentiate from Competence, the
value Promptness during the audit is represented by a timely response to questions and providing
non-technical information back to homeowners immediately. Homeowners’ expectations of
being heard and understood are considered to be important. The evaluation of this outcome is
considered to be achieved through the questions in the post-audit survey preceding the report
delivery.
Classifying Value-Trust Attributes Based on Home Zones (Home-System) 5.7
In addition to the classification based on value dimension and trust attributes, value-trust
may be classified by categorized tasks of home system (s) shown, as Figure 3.3 (Wu & Riley,
2015). The categories of home systems include attic, appliances, cooling, heating, lighting,
renewable energy, water heating, building envelope and living upgrades. However, during the in-
house walkthrough, it is feasible and practical to identify value-trust exchange along with the
walkthrough in home zones, instead of home systems. In order to identify value-trust exchange in
this manner, categories of home systems are simplified into five home walkthrough zones:
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exterior, basement, 1st floor, 2
nd floor and attic. Where, tasks of building envelope and renewable
energy are commonly identified in the exterior walkthrough, tasks of cooling, heating and water
heating equipment are typically happened in the basement and attic. Tasks of appliance, lighting
and living upgrade are mostly in the 1st and 2
nd floor. Tasks of attic occur in the attic inspection.
Identification of value-trust exchange along the home zones enables tracking time spent on each
home zones for further coding and analysis. Table 5.5 shows categorized tasks during audits, and
instances of value-trust exchange for home zones. A completed and detailed list of categorized
tasks can be found in the Appendix A.
Table 5.5 Instances of tasks in home system and the corresponded value dimension and
trust attributes in home zones
Task in home system Instances of tasks during walkthrough Home zone
Living Upgrade -
Identify home
discomfort issues
Sources of discomfort due to thermal conditions enable an
improvement to energy efficiency, which is valuable to
homeowners.
1st floor or 2
nd
floor
Building Envelope -
Inspect home
envelops for air
infiltration issues
Sources of infiltration result to a large (amount) percent of
unwanted heat gain/loss and are addressed through air sealing.
Air sealing is a service that can be acquired/provided
Exterior
walkthrough
Heating- Inspect
home heating system
Inefficient heating system consumes more energy than it is
needed Basement
Appliance- Identify
aged refrigerator for
energy inefficiency
Aged refrigerator results in noise and energy waste, high
efficient refrigerator contribute to keep food fresh with less
energy consumption
1st floor or 2
nd
floor
Attic- Identify attic
issues
Water damage, leaks, seepages, cracks, and mold are among
the most common attic problems. An attic inspection can help
you stop the damage spread rapidly to the rest of your home
Attic
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Coding Tools 5.8
The audio analysis software StudioCode© was used to support a reliable and
standardized process to identify value-trust exchanges and non-value adding time in observed
audit tasks. StudioCode provides visual coding architecture that enables researchers to review
audio and video recordings and the ability to make footnotes and compute time periods via a
simply use interface.
Figure 5.4 shares the coding matrix based on the trust attributes plus a non-value
category. Coding the total time spent on each trust attribute is simple by clicking the labeled
buttons on the StudioCode operating surface. StudioCode can then be used to indicate the
proportion of time spent on each trust attribute. Figure 5.5 provides an example of coding
footnote instances of task details and corresponded trust attributes, as well as the start and finish
times, content, and the categorized trust attribute of incidents. A screen shot of StudioCode
service and footnote are provided in Figure 5.4 and Figure 5.5.
Total time spent on an in-house audit (100%) 58.5 mins
Objective Value (56.4%)
33mins
Competence (48.7%)
28.5 mins
Customization (3.4%)
2 mins
Reliability (3.4%)
2 mins
Promptness (0.9%)
0.5
Subjective Value (37.6%)
22 mins
Similarity (0%)
0 mins
Empathy (0.9%)
0.5 mins
Politeness (11.1%)
6.5 mins
Open & Efficient Communication (25.6 %)
15 mins
No value (6%)
3.5 mins
Figure 5.4.Screen shot of coding matrix in StudioCode
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Coding requires efforts to ensure it is performed in a uniform manner including catching
the key words or the content of conversation of specific types of trust attribute (Table 5.6) :
Table 5.6 Example key words and contents of trust attributes of coding
Trust attributes Key works and contents to identify trust attribute
Competence “Check” equipment and appliances” , “Inspect”, “ the issues can be
solved by using…”
Customization “According to the issues, you can consider option 1 or option 2”
Reliability “The inferred camera shows…”, “ You can access to the DOE
website for more information “, “ the utility company has some
program of …”
Promptness “ We can do more research for you and provide more information
on the report”
Similarity “It is the common issues in this neighborhood”, “ my parents had a
same issue as you do”, “ I am a big fan of Steel too”
Politeness “Should we take off the shoes ?”, “ can we enter this room?”, “ Your
home is very comfortable,” Your collections are beautiful”
Empathy “We understand your concerns”, “we know it is hard to ….”
Open and effective
communication
“Do you think about install solar panels”, “If you are interested in ….
I will recommend you doing ……”
Figure 5.5 Screen shot of instance footnote in an in-house audit
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The coding process was completed by trained auditors who attended nearly thirty in-
house walkthrough in the past two years. The process used to ensure reliability of coding included
two researcher code the same walkthrough separately and do a cross-comparison of coding results
to standardize coding instruments.
The evidence indicating coding was performed in a uniform manner for this research is
demonstrated by standardized walkthrough process, auditors’ training to catch key words and
contents of trust attributes, and the repeated orbits of energy issues in houses.
Chapter Summary 5.9
Chapter 5 discussed data collection and coding of this research. Forty-six survey
and thirty energy audit recordings were collected in the communities near the State
College, PA. A coding instrument with key words and content of energy audit was
developed to identify trust attributes during the energy audit process, and the time period
spent on each trust attributes. Identified trust attributes were converted and tested into
quantitative data by trained auditors. The instrument informed an applied structure for a
statistical analysis of the data set. The specific model development and analysis are
described in Chapter 6.
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Chapter 6
Data Analysis
Chapter 6 presents two approaches to study the value-trust exchange in home energy
audits and homeowners’ actions to enact energy improvements presented in two parts. Part 1
centers on constructing the framework for statistical analysis of survey data and the interpretation
of results. Part 2 demonstrates the analysis of data from in-house recordings and the relationships
between survey results and the auditing recordings.
Part 1: Statistical Analysis of Survey Data
Developing Simple Regression Models for Home Energy Audit Value-Trust Exchange 6.1
This research aims to develop a quantitative approach to assess value-trust exchange(s)
during the home energy audit processes, and study how these value-trust exchanges affect the
intentions of homeowners to implement energy improvements. To do so, a series of models are
presented using four groups of variables to study relationships within auditing processes. These
four groups of variable are referred to as: (1) audit process and recommendation, (2) practical
constraints, (3) characteristics of homeowners and homeowners’, and (3) overall trust level of
home energy audit. These relationships explored between these variables are described below:
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(1) How does homeowners’ overall trust level of an in-house energy audit influence
intention to implement of energy improvements? (Figure 6.1)
(2) How do measureable trust attributes influence homeowners’ intention to implement
energy improvements? (Figure 6.2)
(3) How do practical constraints, such as cost of investments, return on investment,
affordability, safety, health and comfort, and sufficient skill and information
influence homeowners’ intention to implement energy improvement? (Figure 6.3)
(4) How do groups of variables, “Implementation constraints”, “Audit process and
recommendations”, “Homeowners’ overall trust level of energy audit” and
“Homeowners’ personal characteristics” accumulate to influence homeowners’
intention to implement energy improvement? (Figure 6.4)
(5) How do homeowners’ personal characteristics, such as worldview, gender, and
confidence levels in energy improvements, combine to influence intention to
implement energy improvements? (Figure 6.5)
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Figure 6.1 Model 1 represents the relationship between homeowners’ overall
trust level in home energy audits and homeowners’ intention to implement energy
improvement
Homeowner’s
overall trust
Homeowners’ intention
to implement energy
improvements
Homeowner’s
overall trust
Audit
Processes &
Recommendat
ion
Figure 6.2 Model 2 represents the relationship between audit process and
homeowners’ overall trust level in home energy audits.
Figure 6.3 Model 3 includes measurable trust variables to study homeowners’
implementation of energy improvements
Homeowners’ intention
to implement energy
improvements
Audit
Processes &
Recommendat
ion
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Figure 6.5. Model 5 includes homeowners’ personal characteristics, such as worldview,
gender, and confidence level to study the relationships between these variables and homeowners’
intention to implement energy improvement
Homeowners’ intention
to implement energy
improvements
Constraints on
energy
improvements
Homeowners’ intention
to implement energy
improvements
Homeowners’
Characteristics Worldview
Gender
Confidence
level
Figure 6.4 Model 3 focuses on the relationship between practical constraints on
energy improvements and homeowners’ intention to implement energy improvement
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To study the relationships shown above in the Figure 6.1- 6.5, this research develops a
series of five statistical models to represent energy the auditing processes. Model 1 (Figure 6.1)
shows how the homeowners’ overall trust level of audit will influence their home improvement
actions. Model 2 (Figure 6.2) illustrates the selected trust variables used to measure the value-
trust exchange during an in-house audit and how homeowners perceive these variables to their
overall trust level of home energy audit. The selected variables include trust attributes
(Competence, Customization, Reliability, Promptness, Similarity, Politeness, Empathy and Open
& Effective Communication), the priority of recommendations, and the cost categories of
recommendations. Model 3 investigates how these variables influence in homeowners’
implementations of energy improvements. Model 4 (Figure 6.4) adds practical constraints as a
possible influence in homeowners’ actions. Although homeowners may greatly trust the audit
processes and the recommendations provided by the auditors, in reality there are some practical
constraints that could influence their decisions to take actions of energy improvements.
Homeowners’ might ask questions such as “Would this recommendation reduce utility costs?”,
“Would the return on investment (ROI) of this recommendation be good enough?”, “Is this
recommendation affordable?”, “Would this recommendation will increase safety, health and
comfort level in the home?”, and “Do I (the homeowner) have enough skill/information to
implement this recommendation?” Lastly, model 6.5 (Figure 6.5) includes the homeowners’
personal characteristics as possible influences on their implementation of energy improvements.
These characteristics are the homeowners’ gender, and confidence levels in taking action.
Figure 6.6 illustrates the architecture of value-trust exchange during an energy audit with
all the measureable variables from model 6.1 to model 6.5 included. Each group of variables is
broken down into measureable options for further analysis using linear mixed effects models as
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described in Table 6-1. Table 6-1 presents categories of measurable variables against the internal
scaled outcome, which is “When to implement the energy improvements?” Allowed values for
the outcome are “Already done,” “Will do it in 3 months,” “Will do it in a year,” and “Will never
do it.” The scale and computation of these variables is addressed in Chapter 4.4.
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Homeowner’s
overall trust
Homeowners’ intention
to implement energy
improvements
Constraints on
energy
improvements
Save Utility costs
Return of Investment
Affordable
Safety/ Health/
Comfort Information/ Skill
Homeowners’
Characteristics Worldview
Gender
Confidence
level
Audit
Processes &
Recommendat
ion
Priority of
recommendations
Cost categories of
recommendations
8 Trust
Attributes
Figure 6.6 Categorical variables in each group to for the prediction of homeowners’ homeowners’ intention to implement energy improvement
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Table 6.1.Grouped variables are presented with measureable options
Variables Categories Measurement Approach
Trust attributes Competence, Customization, Reliability, Promptness, Similarity, Politeness, Empathy and Open & Effective Communication
Priority of recommendations selected by auditors
Top 1, Top 2, Top 3, Top 4, Top 5 recommendation
Cost categories of recommendations
Category 1 ( < $500) , Category 2 ( $500 ~ $1000) , Category 3 ($1000~$1500), Category 4 ($1500 ~ $3000), Category 5 ( >$3000)
Constraints of energy improvements
Save utility, Return of investment (ROI), affordable cost, increase safety/health/comfort, sufficient information/skill
Homeowners’ personal characteristics
Homeowners’ personal characters: gender, worldview, and confidence level.
The measurable variables are treated as fixed effects, while homeowners’ characteristics
are treated as random effects for the further linear mixed effect analysis. Random effects refer to
the individual specific effects that are uncorrelated with the independent variables. In this
research, homeowners’ characteristics were regarded as random effects while the random effects
can account for individual differences in response to an energy audit, for example, each person
receive an in-house walkthrough with different occasions, the fixed effect estimates the effect of
energy audit to energy improvements, the random effects refers to the allowance of each person
to respond differently.
6.1.1 Linear Mixed-Effects Models
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Linear mixed-effects models are usually used for repeated measurements on the
same statistical units or where measurements are made on clusters of related statistical units. A
mixed-effects model consists of two parts: fixed effects and random effects. Fixed-effects terms
are usually the conventional linear regression part and the random effects are associated with
individual experimental units drawn at random from a population. The standard form of a linear
mixed-effects model is presented as equation 6.1: (Jiang, 2007)
y = Xβ⏟fixed
+ Z⍺⏟random
+ ε⏟error
6.1
Where
y is a vector of observation,
X is a matrix of known covariates
β is a vector of unknown regression coefficients, which are often called the fixed
effects,
Z is a known matrix.
⍺ is a vector of random effects,
ε is a vector of errors.
In this research, observed variables such as selected trust attributes, constraints of energy
improvements, homeowners’ overall trust level in the energy audit, homeowners’ personal
characteristics, cost category, and priority of recommendations are presented as fixed effects
while the randomly signed-up and unknown homeowners are treated as random effects.
Methods of Data Analyses, Model Collinearity and Model Fit 6.2
This research used a combination of multivariate modeling techniques to analyze the
sample data set. Both simple linear regression and linear mixed effects models (MEM) were
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calculated to determine the relationships between grouped variables related to energy audit
processes and audit outcome. Techniques of collinearity statistics and model fit (AIC &BIC) were
applied to select appropriate variables for the mixed effect model analysis.
Collinearity statistics was applied to assess variance inflation factor (VIF) for selecting
appropriate variables for the statistical analysis. VIF measures how much the variance of the
estimated regression coefficients are inflated as compared to predictor variables that are not
linearly related. VIF is used to describe how much multicollinearity (correlation between
predictors) exists in a regression analysis. A rule of thumb is that if the VIF is greater than 10, the
predictors are highly correlated, which means the predictors must be discarded from the model.
This data analysis also applies to the model selection techniques: Akaike’s Information
Criterion (AIC) and Schwarz’s Bayesian Information Criterion (BIC) evaluate model candidates
for mixed effects model analysis. AIC and BIC are the most comment penalized-likelihood
criteria for model selection. AIC estimates the difference between the likelihood function of a
candidate model and the true likelihood function that generated the data, which is unknown. BIC
assumes that there are a fixed number of models available and that one of these models is the true
model. BIC is sometimes preferred over AIC because a low BIC means that the model is
considered to be close to the true model while a low AIC means that the model is more likely to
provide a likelihood function closer to the truth. (Dziak, Coffman, Lanza, & Runze, 2012)
a. Initial Analysis of Data Reliability with Simple Linear Regression
Before analyzing the multiple relationships within the home energy audit with a linear
mixed effects model, a simple linear regression technique was applied to evaluate the reliability
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of the grouped variables presented above. Forty-six response questionnaires were used to analyze
the trust attributes and constraints on energy improvements compared with homeowners’
implementations of energy improvements as four relationships: (A), (B), (C) and (D) (Figure 6.7):
(A) the relationship between selected trust attributes and homeowners’ overall trust
level of the home energy audit.
(B) the relationship between selected trust attributes and homeowners implementation
of energy improvements, and
(C) the relationship between practical constraints on energy improvements and
homeowners’ intention to implement energy improvement.
(D) the relationship between homeowners’ characteristic and implementation of
energy improvements
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Homeowner’s
overall trust
Homeowners’ intention
to implement energy
improvements
Constraints on
energy
improvements
Save Utility costs
Return of Investment
Affordable
Safety/ Health/
Comfort Information/ Skill
Homeowners’
Characteristics Worldview
Gender
Confidence
level
Audit
Processes &
Recommendat
ion
Priority of
recommendations
Cost categories of
recommendations
8 Trust
Attributes
(A) R2 = 65.3%
(B) R2 = 32.98%
(C) R2 = 36.58%
(D) R2 = 0.077%
Figure 6.7 Model 6.4 accumulates groups of measurable variables to study the comprehensive influences of homeowners’ actions to energy
improvements.
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Figure 6.7 presents the preliminary framework for this simple regression test with R-
squared (R2) to test the goodness of fit of the linear model. The test of R
2, collinearity and Normal
probability plot are presented below to assess reliability of each relationship. R2 is used to test
the goodness of fit to the linear model, the collinearity statistics of grouped variables are used to
test the correlations between variables, and the normal probability plot is used to test the normal
distribution of residuals. Minitab was employed to determine the following relationships:
Relationship A Summary
S R-sq R-sq(adj) R-sq(pred)
0.324732 65.30% 57.37% 37.11%
Coefficients
Term VIF
Constant
Competence 3.81
Customization 2.90
Reliability 4.51
Promptness 3.65
Similarity 6.78
Politeness 5.85
Empathy 1.42
O&E Communication 10.72
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Figure 6.8.Normal Probability Plot (left) and Histogram (right) – trust attributes against
homeowners’ overall trust level of home energy audit
The R2 value of 65.3% reveals a strong relationship between the selected trust attributes
and homeowners’ overall trust level in this model. There are indicators of collinearity of
predictors. As a rule of thumb, if VIF is more than 10, then the predictor from the model is
discarded and in this case the VIF of the predictor “Open & Efficient Communication” is 10.72.
This indicates that there is high collinearity with other predictors, and this predictor should be
discarded. Figure 6.8 presents the normal probability plot (left) and histogram (right) of the data,
the plotted points follows the straight line, while the histogram appears normal in this regression
model.
Relationship B Summary
S R-sq R-sq(adj) R-sq(pred)
0.150501 32.98% 13.84% 0.00%
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Coefficients
Term VIF
Constant
Competence 4.08
Customization 3.21
Reliability 6.27
Promptness 4.47
Similarity 5.69
Politeness 5.58
Empathy 1.36
O&E Communication 11.33
Figure 6.9.Normal Probability Plot (left) and Histogram (right) – trust attributes against
homeowners’ actions to energy improvements
Similarly to Relationship A, relationship B has an R2 value of 32.9%, suggest that 32.9%
of the variation in the response variable (homeowners’ intention to implement energy
improvement) can be explained a linear relationship with the predictors (trust attributes).
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Meanwhile, the VIF of predictors “Open & Effective Communication” is 11.33, which again
requires it be discarded. Figure 6.9 shows that the plotted points follow the straight line, while the
histogram appears normal in this regression model.
Relationship C Summary
S R-sq R-sq(adj) R-sq(pred)
0.316073 36.58% 34.93% 32.48%
Coefficients
Term VIF
Constant
Saving utility 2.36
ROI 2.33
Affordable cost 1.42
Living upgrade 1.35
Information Skill 1.45
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Figure 6.10.Normal Probability Plot (left) and Histogram (right) – constraints of energy
improvements against homeowners’ actions to energy improvements
The result for relationship C reveals the R2 value of 36.6%, which suggests 36.6%
variation in the response variable (homeowners’ action to energy improvement) can be explained
by constraints on energy improvements. The VIF of the predictors (variable of audit
recommendations-saving utility, return of investment, affordable cost, living upgrade and
information and skill) are smaller than 10, which means none of the predictors must be
discarded. Figure 6.10 shows that the plotted points follow the straight line, while the histogram
appears normal in this regression model.
In addition to the trust attributes and constraints on energy improvements, the variables of
homeowners’ worldview, gender, and confidence levels are also studied for influence of
homeowners’’ actions as relationship D in Figure 6.7. The R2 value of 0.077 shows that the
homeowners’ characteristics, such as worldview, confidence level and gender as defined in this
approach have very limited connection to homeowners’ intentions to implementation of energy
improvements.
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Mixed effects model selection with SPSS 6.3
In addition to test the reliability of grouped variables, AIC and BIC indices are also
applied to evaluate the model fit of mixed effect models. Several of model candidates are
provided in Table 6.2 with corresponding AIC, BIC, and the groups of variables. AIC and BIC
are two measures of the relative quality and truth of the model. AIC tries to select the model that
most adequately describes an unknown, high dimensional reality while BIC tries to find the true
model among a set of candidates. Smaller values of AIC and BIC are expected to indicate better
models. When fitting models, it is possible to increase the likelihood by adding parameters but
doing so may result in overfitting. Overfitting generally occurs when a model is excessively
complex, such as having too many parameters relative to the number of observations (James,
G.2013).
Table 6.2. Summary of candidate models with corresponding AIC, BIC, and grouping
predicators.
Groups of Predictors
Model # of variables
AIC BIC Homeowner Trust
Attributes
Constraints Overall Trust
Cost + Priority
A 31 139 145 x x x x x
B 26 203 210 x x x x
C 23 133 139 x x x
D 24 123 130 x x x x
E 21 199 205 x’ x x
F 25 134 140 x x x x
N=230. x in the column of trust attribute includes Competence, Customization, Reliability, Promptness,
Similarity, Politeness, Empathy and Open and Effective communication. x’ in the column of trust attributes =
Competence, Customization, Reliability, Promptness, Similarity, Politeness and Empathy.
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Model A contains all of the groups of predicators in the model, which include
homeowners’ personal characteristics, seven trust attributes, constraints on energy improvements,
homeowners’ overall trust level of home energy audits, cost categories, and the priority of
recommendations. Although the values of AIC (139) and BIC (145) are relatively low, with 31
variables this model is overfitting. Compared with Model A, Model B excludes the constraint on
energy improvements group and results in higher AIC (203) and BIC (210), which indicates that
the constraints on energy improvements are critical factors in the model. Model C includes the
predictors of homeowners’ personal characteristics, constraints on energy improvements, cost
category, and priority of recommendations. Model D includes the predictor groups in model C
and the homeowners’ overall trust level in the home energy audit. The resulting AIC (123) and
BIC (130) are both slightly lower than for model C, which means homeowners’ overall trust level
should be critical predictors in this model. Compared with model A, model E removes the
predictors of homeowners’ personal characteristics and results in smaller values of AIC (134) and
BIC (140), indicating the difficulty of expressing homeowners’ characteristics in this model.
Model E and F were selected as the fittest models for the mixed effects model analysis due to the
investigation of critical predictors. Model E (AIC-199, BIC-205) employs the concept of studying
value-trust exchange in home energy audits and contains predictors of eight trust attributes,
homeowners’ overall trust level of the home energy audit, cost category, and priority of
recommendations. The model F (AIC-134, BIC-140) includes the critical predictors of this trust
research: the trust attributes constraints on energy improvements, homeowners’ overall trust level
in the home audit, cost category, and priority of recommendations.
As noted above, forty-six valid surveys were collected for this research in which each
homeowner was asked to provide feedback on five recommendations, and thus forty-six
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responses can be expanded into a two hundred data point sample for the mixed effects model
analysis. However, in order to expand the data set, the priority of recommendation was set up as a
prerequisite for the mixed effects model. Additionally, cost category of each recommendation
was counted as one of the predicators. The calculated mixed effects model E and F are presented
in Figures 6.11 and 6.12.
6.3.1 Interpretation of the mixed effects model E
Model E (Figure 6.11) includes grouped attributes of trust, priorities of recommendations,
cost categories of recommendations, and homeowner’s overall trust level of the energy audit to
predict homeowners’ intention to implement energy improvement. Figure 6.11 presents the model
diagram and relationships between grouped variables. Table 6.3 displays the summary of the
fixed effects with highlighted significant variables (p < 0.05). The significant variables that
influence homeowners’ intention to implement energy improvement include “Customization (p =
0.002)”, “Similarity (p = 0.028)”, “Open and effective communication (p = 0.028)”, as well as
“Priority of recommendations (p = 0.001)” and “Cost category of recommendations (p = 0.011)”.
However, as discussion in the simple regression relationships A and B, the trust attribute “Open
and Effective Communication” had the VIF value greater than 10 and is discarded.
Table 6.4 presents the estimates of effects table that is produced by choosing “parameter
estimates” under statistics for categorical variables. In model E, “cost category 5
recommendations” and “priority of recommendation = 5” were both set up as the baseline to
compare variables in the same group. Therefore, the intercept value of 0.746502 represents
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homeowners’ intention to implement energy improvement for cost category 5 recommendations
in the top 5 recommendations.
The intercepts for cost categories 1, 2, and 3 are shown to be significant relative to the
baseline cost category 5 (p < 0.05), which means that homeowners are more likely to implement
energy improvements if the recommendations are in the cheaper cost categories category 1 (less
than $500), category 2 ($500~1000), and category 3 ($1000~1500). Similarly, priority of
recommendation 1, 2, and 3 are shown to be significant relative to the baseline priority of
recommendation 5 (p < 0.05). This means that homeowners are more likely to implement energy
improvements when these recommendations were prioritized as the Top 1 (p=0.000), Top 2
(p=0.000), or Top 3 (p= 0.044) recommendation based upon feasibility and homeowners
preference. A complete diagram of the model E that includes all paths and variable paths is
provided in Appendix B.
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Homeowner’s
overall trust
Homeowners’ intention
to implement energy
improvements
Audit
Processes &
Recommendat
ion
Priority of
recommendations
Cost categories of
recommendations
Competence
Customization
Reliability
Promptness
Similarity
Politeness
Empathy
O&E
Communication
P=0.865
P=0.002
P=0.993
P=0.154
P=0.028
P=0.133
P=0.434
P=0.028
P=0.07
P=0.001 P=0.011
Figure 6.11 Mixed effect model E with eight trust attributes, homeowners’ overall trust of home energy audit and cost category and priority of
recommendations to against to homeowners’ action to energy improvements.
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Table 6.3. Type III tests of fixed effects for the mixed effects model E
Source df F Sig.
Intercept 1 13.421 .000
Cost Category 4 3.376 .011
Priority of recommendation 4 5.152 .001
Competence 1 .029 .865
Customization 1 9.866 .002
Reliability 1 .000 .993
Promptness 1 2.044 .154
Similarity 1 4.916 .028
Politeness 1 2.275 .133
Empathy 1 .616 .434
Overall trust level 1 3.310 .070
O&E Communication 1 4.918 .028
Table 6.4. Estimates of fixed effects for model E
Parameter Estimate Std. Error t Sig.
Intercept .746025 .302867 2.463 .015
[Cost Category=1] .302802 .090433 3.348 .001
[Cost Category=2] .275094 .136147 2.021 .045
[Cost Category=3] .186643 .094890 1.967 .051
[Cost Category=4] .131943 .111963 1.178 .240
[Cost Category=5] 0b 0
[Priority of recommendation=1] .286057 .080323 3.561 .000
[Priority of recommendation=2] .287903 .080327 3.584 .000
[Priority of recommendation=3] .162050 .080086 2.023 .044
[Priority of recommendation=4] .063682 .079011 .806 .421
[Priority of recommendation=5] 0b 0
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Interpreting the results for the mixed effects model F
In addition to model E’s predictors, model F (Table 6.5) includes the constraints on
energy improvements, which focuses attention on the influence of the significant variables on
homeowners’ intention to implement energy improvement. Figure 6.12 presents the diagram of
the model with grouped variables and relationships. Compared with the selected trust attributes in
a home energy audit, the constraints on energy improvements have a significant effect on
homeowners’ implementation of energy improvements, such as “Return on investment (p =
0.000)”, “Affordable cost (p = 0.005)”, “Information and skill (p = 0.001)”, “Homeowners’
overall trust level of energy audit (p = 0.035)” and “Cost category of recommendations (p =
0.030)” all are shown to have a significant effect on homeowners’ intention to implement energy
improvement. This means that when homeowners consider taking actions for the energy
improvement of their home, they are more likely to focus on the return of investment, affordable
cost of the investments, and the information and skill to implement improvements. These results
also reflect the intuitive response one would expect from homeowners and indicate the survey
instrument is capable of producing useful results.
Table 6.6 presents the estimates of effect produced by choosing “parameter estimates”
under statistics for categorical variables. Similar to model E, “cost category = 5” and “priority of
recommendation = 5” were set up as baselines to compare other categorized variables. Thus,
when comparing the categorical variables to the baseline (cost category 5 and priority of
recommendations 5), cost category 1 (p= 0.001), 2 (p=0.059), and 3 (p=0.027) have significant
effect on homeowners’ intention to implement energy improvement, which means that
homeowners are more likely to invest in energy improvements when the recommendations cost
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less than $1500 (category 1 is less than $500, category 2 is in the range $500~$1000, and
category 3 is in the range $1000~$1500).
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Homeowner’s
overall trust
Homeowners’ intention
to implement energy
improvements
Audit
Processes &
Recommendat
ion
Priority of
recommendations
Cost categories of
recommendations
Competence
Customization
Reliability
Promptness
Similarity
Politeness
Empathy
P=0.627
P=0.849
P=0.201
P=0.457
P=0.418
P=0.198
P=0.762
P=0.035
P=0.564 P=0.030
Return of
Investment
Affordable
Cost
Safety/ Health/
Comfort
Information
/ Skill
Save
Utilities
P = 0.675 P = 0.000 P = 0.005 P = 0.97 P = 0.001
Constraints of
energy
improvements
Figure 6.12 Mixed effect model F of seven trust attributes, constraints of energy improvements, homeowners’ overall trust of home energy
audit and cost category and priority of recommendations.
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Table 6.5. Type III tests of fixed effects for the mixed effects model F
Source df F Sig.
Intercept 1 .373 .545
Cost Category 4 2.746 .030
Priority of recommendation 4 .744 .564
Saving utility 1 .176 .675
ROI 1 20.463 .000
Affordable cost 1 8.183 .005
Living upgrade 1 2.800 .097
Information /Skill 1 11.546 .001
Competence 1 .241 .627
Customization 1 .037 .849
Reliability 1 1.697 .201
Promptness 1 .568 .457
Similarity 1 .671 .418
Politeness 1 1.725 .198
Empathy 1 .093 .762
Overall trust level 1 4.840 .035
Table 6.6. Estimates of fixed effects for model F
Parameter Estimate Std.
Error df t Sig.
Intercept -.008539 .306914 35.445 -.028 .978
[Cost Category=1] .259171 .079903 168.772 3.244 .001
[Cost Category=2] .223278 .117575 170.831 1.899 .059
[Cost Category=3] .181550 .081226 170.141 2.235 .027
[Cost Category=4] .152629 .095482 167.098 1.599 .112
[Cost Category=5] 0b 0
[Priority of recommendation=1] .039294 .069189 150.712 .568 .571
[Priority of recommendation=2] .095760 .067918 147.502 1.410 .161
[Priority of recommendation=3] .034297 .065961 145.688 .520 .604
[Priority of recommendation=4] -.007011 .065471 145.060 -.107 .915
[Priority of recommendation=5] 0b 0
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6.3.2 Summary of mixed effects models E and F
Part 1 of chapter 6 discussed the analysis of the results of the survey questionnaire. A
series of models were developed and evaluated via statistical techniques (VIF, AIC/BIC). Model
E contains variables of trust attributes, categories of recommendation cost and priority, and
homeowners’ overall trust level. Analysis results indicate that the trust variables “Customization”
and “Similarity” are significant contributors to homeowners’ intention to implement energy
improvements, which means that homeowners are more likely to implement energy
improvements of his/ her home when they believe that energy audit is customized to their issues
and their concerns are being heard.
However, when the model is extended to include practical constraints on implementations
of energy improvements, the result of model F indicates that the constraints of “Cost of
investments”, “Return of investment”, “Affordable cost”, “Information and skill to conduct
energy improvements”, and “Overall trust level of energy audit” are the significant factors that
influence homeowners’ actions. This result implies that when faced with practical constraints
upon their ability to implement energy improvements, they focus on the cost of the
improvements, the information needed to carry out the improvements, and the trust relationship
with the auditor. Also, potentially owing to the small size of the dataset, the variables of
homeowners’ personal characteristics (such as gender, worldview, and confidence level in the
energy audit) are not a significant influence on homeowners’ intention to implement energy
improvements,
In summary, the following statements characterize the results of the data analysis in terms
of the variables found to most influence intention to implement improvements.
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Considering only the audit process (Model E), the following factors are significant:
Customized solutions to homeowners’ energy issue
Homeowners are being heard and see similarities in the situations of others.
Considering the audit process and practical constraints (Model F), the following factors
are significant:
Investment is affordable with the cost less than $ 1500.
Homeowners understand the return on investment of the upgrade
Homeowners have sufficient skill and information to conduct energy
improvements.
Homeowners have higher trust relationships with auditors and the
recommendations.
Part 2: Home Energy Audit Recording Analysis
Part 2 seeks to characterize interactions during the audit process that could help to build
trust relationships with homeowners. Thirty in-house energy audits were recorded to study time
and effort spent. Studying the interactions with homeowners and the length of time spent on
selected trust variables is performed to more deeply examine how auditors can build trust
relationships with homeowners, ultimately leading to taking action to enhance the energy
efficiency of their homes. Two analyses of in-home audit recording data are presented; including
(1) the analysis of time spend in variable zones of the home, and (2) the analysis of the types and
distribution of value-trust exchanges distributed through audit processes.
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The time period spent on each house zone was tracked on audit recordings, to study time
period spent on which house zone during an in-house audit, and auditors were required to name
the zone when entering the categorized spaces to record the time of entry. Equation 5.1 is used to
calculate the proportion of time spent on each zone.
Percentage zone = 𝑇𝑖𝑚𝑒 𝑠𝑝𝑒𝑛𝑡 𝑜𝑛 𝑐𝑎𝑡𝑒𝑔𝑜𝑟𝑖𝑒𝑑 𝑧𝑜𝑛𝑒𝑠 𝑜𝑓 ℎ𝑜𝑢𝑒𝑠
𝑂𝑣𝑒𝑟𝑎𝑙𝑙 𝑡𝑖𝑚𝑒 𝑠𝑝𝑒𝑛𝑡 𝑜𝑛 𝑎𝑛 𝑖𝑛−ℎ𝑜𝑢𝑠𝑒 𝑎𝑢𝑑𝑖𝑡
Table 6.7 indicates the average time in minutes and proportion of time in percentage
spent on each space zone of thirty audit houses with the NELC energy audit. The data reveal that
the average time spent on an in-house audit is 86.51 minutes, of which 32 minutes were spent on
interview, 12 minutes on exterior walkthrough, 4.1 minutes on the garage, 10.7 minutes on
basement (or mechanical room) walkthrough, 14.4 minutes on the first floor (living room,
kitchen, etc.), 8.7 minutes on the second floor (bedrooms and bathrooms), and 4.3 minutes on the
attic.
Table 6.7.The average time in minutes and proportion of time in percentage spent on each
space zone of thirty audit houses.
Total Time
Interview Duration
Exterior Duration
Garage Duration
Basement Duration
First Floor Duration
Second Floor
Duration
Attic Duration
mins 86.51 32.03 12.1 4.16 10.72 14.41 8.71 4.32
% 100% 37.03% 13.99% 4.81% 12.4% 16.66% 10.07% 5.05%
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An initial regression is provided to indicate the relationship between time spent on home
zone of collected data and homeowners’ intention to energy improvement. Model G applies the
linear regression to study the relationship between homeowners’ intention of energy
improvements and “time spent on each house zone: interview, exterior, interior, garage,
basement, first floor, second floor and attic”. Low value of R2 (4.15%) reveals that the model G
has very limited fitness to indicate the relationships between “time spent on each house zone” and
“homeowners’ implementations of energy improvements”. Meanwhile, the summary of model G
also refers that time spent on house zone does not reveal significant effect on homeowners’
intention of energy upgrade, since the P-value of each zones are greater than 0.05 with high
collinearity (VIF > 10).
Time spent on
each zones
T_Intervie
T_Exterior
T_Garage
T_Basemen
T_1st Floor
T_2nd
T_Attic
Figure 6.13 Model G is created to indicate the relationships between “time (%) spent
on each zone” and “Homeowners’ intentions to implement energy improvements.
Homeowners’ intention
to implement energy
improvements
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Model G Summary
S R-sq R-sq(adj) R-sq(pred)
0.379813 4.15% 0.00% 0.00%
Coefficients
Term Coef SE Coef T-Value P-Value VIF
Constant -1.21 5.95 -0.20 0.840
T_ Interview 1.72 5.99 0.29 0.775 520.05
T_Exterior 2.22 6.16 0.36 0.719 120.50
T_ Garage 2.03 5.81 0.35 0.727 47.63
T_ Basement 2.12 5.70 0.37 0.711 91.09
T_First Floor 2.01 6.05 0.33 0.740 158.32
T_Second Floor 0.88 6.02 0.15 0.884 133.39
T_Attic 2.47 6.11 0.40 0.687 41.09
In addition, model G shows the difficulty to indicate the relationship between “time spent on
home zones” and “homeowners’ intention to implement energy improvements” because of the
high collinearity between each trust attributes and small size of data. The recording data also
reveal the difficulty to indicate the relationship between time spent on home zones and home
owners’ intention to energy improvements. Compare the survey data with the recording data of
home A and B. Homeowner A and homeowner B both have the worldview of Cautious
Conservative and have the similar size home. Three of the same recommendations of home
improvements were recommended to both homes, however, Fifty minutes were spent to complete
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an in-house audit with homeowner A, when ninety- one minutes were spent to complete home B
walkthrough. Homeowner A did present the relatively high level of trust relationship with auditor
and high interest to conduct energy improvements, while homeowner B presented relative low
trust relationship with auditors with less interest in conducting energy improvements of home
(Table 6.8. Completed survey of home A and home B can be found in appendix D). Various
variables, such as home size and homeowners’ concerns greatly vary homeowners’ intention to
implement energy improvement.
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Table 6.8 Cases comparison of in-house audits
Time spent on zones (minutes)
Name World View SQFT
# Bedroom
# Bathroom Interview Exterior Basement 1st floor 2
nd floor Attic Total time
A
Cautious Conserv
ative 1620 3 1 18 8 11 10 n/a 3 50
B
Cautious Conserv
ative 1950 3 1.5 35 16 11.5 19 8 1.5 91
Recommendations for Homeowner A (Implement time)
1. Insulate Attic (next 3 month)
2. Seal Ductwork (next 3 month)
3. Insulate water piping (next 3 month)
4. Insulate basement ceiling (next 3 month)
5. Weatherize door (next 3 month)
Recommendations for homeowner B (Implement time)
1. Insulate water pipe (month 3 month)
2. Weatherize door (next 3 month)
3. Insulate basement ceiling (no plan)
4. Add gas fireplace insert (no plan)
5. Upgrade to LEDs (next year)
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b. Interpretation of audit recording data
Part 2 discusses the data from collected audit recordings, revealing “how much time has
spent on each zone and the type of trust attributes to contribute to auditing performance. To
quantitatively study time spent on particular trust attributes during an in-house audit, three coding
layers were constructed with StudioCode. The first layer is the total time spent on in-house audit
(without the interview), which varies from 40 minutes to 108 minutes. The second layer addresses
the time spent on value dimensions: objective value, subjective value, and non-value. The third
layer contains the categories of trust attributes underneath the value dimensions. The system
records not only the period of time spent on each category, but also calculates the proportion
between time periods. Therefore, the same system is applied and presented in a manner of
percentage format, which addresses time spent on each trust attribute over the overall time of an
in-house audit. Equation 6.2
Percentage trust attributes = 𝑇𝑖𝑚𝑒 𝑠𝑝𝑒𝑛𝑡 𝑜𝑛 𝑜𝑛𝑒 𝑡𝑦𝑝𝑒 𝑜𝑓 𝑡𝑟𝑢𝑠𝑡 𝑎𝑡𝑡𝑟𝑖𝑏𝑢𝑡𝑒
𝑂𝑣𝑒𝑟𝑎𝑙𝑙 𝑡𝑖𝑚𝑒 𝑠𝑝𝑒𝑛𝑡 𝑜𝑛 𝑎𝑛 𝑖𝑛−ℎ𝑜𝑢𝑠𝑒 𝑎𝑢𝑑𝑖𝑡 6.2
The thirty in-house audits were recorded during late March to early July, 2015. Excluding
the interview time (average 32 minutes), the average time spent on an in-house walkthrough is
55.35 minutes, of which nearly 30 minutes were spent on generating objective value, 21 minutes
spent on generating subjective values, and nearly 5 minutes is wasted on non-value activities, as
shown in the Table 6.9. Meanwhile, Table 6.9 also states that 54% of time is spent on Objective
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value, while 46.8% of time is spent on Competence, 3.6% of time is spent on Customize, 4% of
time is spent on Reliability and 0.2% is spent on Promptness. The major reason results are
skewed toward Competence is that the in-house audit is typically treated as a technical service,
which relies heavily on auditors’ skills and knowledge to inspect components as a check list. The
proportion of time spent on Customization, Reliability, and Promptness are relatively low because
opportunities to generate these three trust attributes are random and depend upon the
environment. A similar phenomenon occurs with subjective value (36.3%) – most of the time is
spent on communication (29.9%) to understand the house conditions and homeowners’
preferences and concerns, while a smaller proportion of time is spent on the trust attributes of
Similarity (1.4%), Empathy (0.5%) and Politeness (4.6%). In addition to time spent on trust
attributes, 9% of audit time is spent transferring between zones and waiting, which contributes to
no value in each case.
Table 6.9. The average time spent on each trust attribute in an in-house audit.
Total Time: 55.35 mins (100%)
No-Value: 4.95 mins (9.1%)
Objective
Value Competence Customization Reliability Promptness
29.75 26.40 2.00 2.24 0.14
(54.6%) (46.8%) (3.6%) (4.0%) (0.2%)
Subjective
Value Similarity Empathy Politeness Communication
20.82 0.74 0.24 2.47 18.09
(36.3%) (1.4%) (0.5%) (4.6%) (29.9%)
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Analysis of audit recording data 6.4
To study the relationship between “building trust during the audit” and “time spent on
trust attributes,” linear regression techniques are applied to analyze the thirty in-house audit
recordings. Owing to the different periods of time required to complete each in-house audit, the
time spent on each trust attribute was converted into percentages of overall time spent on an in-
house audit. The audit recordings are mainly used to indicate the extent to which “time spent on
trust attributes” can contribute to, (1) homeowners’ overall trust level of energy audit or (2)
homeowners’ intention to implement energy improvement as shown in Figure 6.13.The
contributions are analyzed as relationships H and I with linear regression analysis.
Relationship I Summary – Time spent on trust attributes vs. homeowners’ overall
trust level of energy audit
Time spent on
trust attributes
(I)
(J)
Figure 6.14 Mode H, Relationship I and J discuss the relationships between "time
spent on trust attributes" and homeowners' overall trust level" and "intentions to energy
improvements"
Homeowners’ intention
to implement energy
improvements
Homeowner’s
overall trust
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S R-sq R-sq(adj) R-sq(pred)
0.401155 27.40% 25.33% 23.13%
Coefficients
Term Coef SE Coef T-Value P-Value VIF
Constant 3.687 0.114 32.26 0.000
T_Customization 4.59 1.04 4.42 0.000 1.11
T_Promptness -28.29 8.12 -3.48 0.001 1.19
T_Politness -4.25 1.15 -3.69 0.000 1.08
T_Communication 0.394 0.260 1.51 0.132 1.07
Regression Equation
Overall trust level = 3.687 + 4.59 T_Customization - 28.29 T_Promptness -
4.25 T_Politness + 0.394 T_Communication
Based on the analysis of the thirty recorded energy audits, the R2 value indicates that
27.4% of the response variable variation is explained by the Relation I. Three trust attributes are
shown to be significant as the result of the Relation I in the linear regression analysis. These are
“Customization (p= 0.000)”, “Promptness (p= 0.001)”, and “Politeness (p= 0.000)”. Furthermore,
the sign of the coefficients indicates that spending more time on the trust attribute of
“Customization” and less time on responding to homeowners (Promptness) and Politeness results
in better trust levels between homeowners and auditors during the in-house audit.
Relationship J Summary- Time spent on trust attributes v.s. homeowners’
intentions to make energy improvements.
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S R-sq R-sq(adj) R-sq(pred)
0.389431 1.14% 0.00% 0.00%
The summary of relationship J shows a low goodness-of-fit rate (R2 of 1.14%) to explain
the variability of the response data around its mean. Additionally, no significant trust attributes
were found in the analysis between time spent on trust attributes and the homeowners’ intention
to implement energy improvements (Relation J). Detailed data can be found in the appendix C.
Based on these results, the subsequent analysis is focused on the Relation I to explore
relationships between survey data and recording data.
Interpretations of audit recording analysis
Model F indicates that practical constraints of energy improvements have much more
significant influence on homeowners’ intention to implement energy improvements than trust
attributes, homeowners’ overall trust level of the energy audit still plays an significant role (P =
0.035) on homeowners intentions. When Relation H indicates time investments on
Customization, Promptness, Politeness and Communication may vary the trust relationship with
homeowners.
In light of this result, a combined analysis of model E, F and H is explored to detect the
influence of more specific interactions during an in-house energy audit. This combined analysis is
120
120
shown in Figure 6.14. The combination of models E, F and H shows that “time spent on trust
attributes” could increase homeowners’ trust level of energy audit, as well as actions.
121
121
Homeowner’s
overall trust
Homeowners’ intention
to implement energy
improvements
Audit
Processes &
Recommendat
ion
Cost categories of
recommendations
P=0.035
P=0.030
Return of
Investment
Information
/ Skill
Affordable
Cost
P = 0.005 P = 0.000 P = 0.001
Constraints of
energy
improvements
Figure 6.15 Combined results of Model E,F and H to present (1) significant factors, (2) time spent on significant trust attributes can increase
homeowners' implementations of energy improvements of their homes.
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Model E reveals that the specific trust attributes “Customization”, “Similarity”, and
“Open and effective communication” contribute to homeowners’ intention to implement energy
improvement (the trust attributes in bold print in Figure 6.14). Model H reveals more time spent
on the trust attribute “Customization” and verses time spent on the trust attributes “Promptness”
and “Politeness” contributes to homeowners’ overall trust level of the energy audit. In Figure
6.14: “+” indicates more time is needed and “-” means that less time is needed to contribute to
homeowners’ overall trust level.
Figure 6.14 summarizes the significant factors influencing homeowners’ intention to
implement energy improvements and provides a response to the research question: “What factors
contribute to homeowners’ intention to implement energy improvements?” In addition to cost
related factors, such as “Return on investment,” “Affordable cost of investment” and “Enough
information on energy improvements,” having a trust relationship between homeowners and
auditors, providing customized service, and sharing similar experiences or concerns in response
to homeowners’ energy issues are also found to be significant factors influencing homeowners
intention to take action. The approach to generate trust relationships with homeowners during an
in-house audit could thus be focused on spending more time on customized auditing services so
that the homeowner receives solutions that specifically meet their unique conditions.
Homeowners are more likely to trust the audit team when they responded in the shorter time
(promptness) with more technical conversations over politeness. More specific, examples of
interactions engaged in building trust relationship were observed and summarized from in-house
audit recordings and presented as Table 6.10 :
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Table 6.10 Summary of observed interactions in the in-house audit that were found to
contribute to homeowners' intention to implement improvements.
Significant trust attributes Interactions observed in the in-house audit
Customization Discussing kitchen ideas based on home and desires
Suggest and explain weather-strip based on needs
Recommend choices of insulation for this home
Similarity
Compare other experiences and the design of cat-door
Discuss other homes and their blind issues for high windows, and what solutions we recommended.
Discuss other local home and what we have witnessed compared with their home
Politeness
Compliments on homeowners’ safety habits and features
Show respect and appreciation to have auditors in homes
Ask do homeowners have other questions that haven’t be discussed
Ask about family members
Ask homeowners about taking off shoes before enter home
Ask to close the door after checking the room
Thank you & goodbye
Promptness Present reactions to homeowners’ questions
Indicate follow-up research is required to answer homeowners’ questions
Chapter Summary 6.5
Chapter 6 presents systematic approaches to measure grouped variables related to value-
trust exchange in in-house audit through surveys and audio recording. A series of frameworks
were created to study the value-trust exchange in home energy audits and homeowners’ actions to
enact energy improvements presented. Statistical analysis of survey data reveals that variables,
such as “return on investment,” “affordable cost,” and “sufficient information and skills” are the
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significant factors to enhance homeowners implementing home improvements. Furthermore, the
analysis of data from in-house recordings and the relationships between survey results and the
auditing recordings also indicate that homeowners’ overall level of trust can be increased through
time spent on customizing solutions to energy issues and immediate response to homeowners.
The instances that generate trust through interactions between homeowners and audits were also
be observed and summarized for improving audit processes.
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Chapter 7
Conclusions
This chapter summarizes the key findings, contributions, and limitations of this research.
This research includes the development of a value-oriented approach to home energy audits based
on a framework created to describe value-trust exchange during the audit process. Groups of
latent factors affecting the intention to implement energy improvements are defined. In-house
audit processes were recorded and measured systematically to identify the significant factors that
contribute to homeowners’ intention to implement energy improvements. The significant findings
from the mixed effects model calculation are presented and discussed relative to in-house audit
practices. Research limitations and potential opportunities of future work are also presented.
Summary of Findings 7.1
An examination of the home energy audit process was conducted in this research. The
NELC energy audit approach emphasizes value-oriented audit performance, which centers on a
value-trust exchange during the auditing processes. Measurable variables of value-trust exchange
were reviewed in literature and industrial practices and selected to investigate the interactions and
trust relationships between homeowners and auditors in an energy audit.. This research
demonstrates that differences in auditing processes, interactions between auditors and
homeowners, and the types of recommendations of energy improvements influence homeowners’
intentions to act upon recommendations. Audit processes that accumulate a greater numbers of
trust exchanges were also found to improve homeowners’ intention to implement energy
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improvements. A structured framework was developed and assessed to investigate the impact of
grouped variables in audit processes. This research used data from forty-six questionnaire
surveys and thirty in-house audit recordings, providing two methods to measure value-trust
exchange in an audit. The survey focuses on homeowners’ post-audit evaluation and was found to
be a useful instrument in evaluating the results of an audit from the perspective of the customer.
The in-house audit recording focuses on capturing real-life value-oriented interactions that
contribute to trust relationships between homeowners and auditors.
The indicators to assess these interactions involved groups of variables classified as: (1)
Audit processes and recommendation, (2) Homeowners’ overall level of trust, (3) Constraints on
energy improvements, (4) Characteristics of homeowners and (5) Time spent on trust attributes.
Variables of “Audit processes and recommendations” were used to evaluate value-trust exchange
in an in-house audit with priority and cost categories. Homeowners’ overall trust level of the
energy audit was used to assess homeowners overall trust relationship with the auditing team.
Variables of Constraints of energy improvements were used to indicate practical concerns related
to intention to implement home energy improvements. Variables of Characteristics of
homeowners” refer to latent differentiations between homeowners’ worldview, gender, and
confidence level of energy improvements in real life.
The relationships between grouped variables were analyzed by linear regression and
mixed effects model analysis. Linear regression is used to assess the reliability of grouped
variables, while the mixed effects model is used to detect significant variables influencing
homeowners’ implementation of home improvement in different situations:
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a) How the audit process (trust attributes, priority and cost category of recommendations)
and homeowners’ overall trust level of energy audit influence homeowners’ intention to
implement energy improvements (model E).
b) How constraints on energy improvements and the groups indicators in model E influence
homeowners’ intention to implement energy improvements (model F).
Measurable variables were initially chosen and studied with a simple linear regression,
which indicates reliability of trust variables, latent characteristics of homeowners in the in-house
audit and recommendation processes. Seven out of eight trust attributes and five out of five
constraint variables present reliable influence (VIF < 10) upon the homeowners’ implementations
of energy improvement. The linear regression demonstrates the relationship between audit
variables and homeowners’ implementations of energy improvements are summarized:
1) Trust attributes for audit processes: Eight trust attributes were selected from theoretical
and industrial research and tested with linear regression. Seven out of eight trust
attributes reveal reliable influences (VIF <10) with relatively high explanation rate of
either homeowners overall trust level of energy audit (R2 = 65.3%) and implementations
to energy improvements (R2 = 32.98%). Those attributes are “Competence”,
“Customization”, “Reliability”, “Promptness”, “Similarity”, “Politeness”, and “Empathy”.
2) Constraints on energy improvements: Five constraints on energy improvements present
reliable impact (VIF < 10) in homeowners’ actions with the overall variation explanation
rate R2=36.58%. The variables are “Utility savings”, “Return of investment”,
“Affordable cost”, “Increase safety/ health/comfort”, and “Sufficient information and
skill”.
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In addition to determining the reliability of variables for further analysis, the mixed
effects model presents a comprehensive overview of relationships among grouped variables and
homeowners’ actions. Model E reveals trust attributes of “Customization (P = 0.002)”,
“Similarity (P = 0.028)” and “Communication (P = 0.028)” have significant impact on
homeowners’ intention to take action.
The types of recommendations have an elevated influence on homeowners’ actions, and
contribute to overcoming trust barriers identified in previous research. Homeowners are more
willing to implement energy improvements when the investments are affordable (p = 0.005) –
financial barrier, the return of investment is reasonable (p= 0.000) and when they have sufficient
knowledge and skill to take action (p = 0.001) – information barrier, as well as having a strong
trust relationship with auditors (p= 0.035) – trust barrier.
This research demonstrates that many differences in value-trust interactions, constraints
on energy improvements and homeowners’ characteristics are attributable to homeowners’
intentions to make energy improvements in their homes. Traditional audit processes focus on
technical conditions in homes and estimated return on investments. The recording analysis in this
research indicates that homeowners are more interested in energy improvements when auditors
spent more time on customization of audit services. This research also indicates that
understanding homeowners’ concerns and preferences and providing feasible improvements
increases the likelihood that homeowners will act on energy upgrades.
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Research Contributions 7.2
This research reveals four contributions to the home energy audit industry, which are (1)
identification of value-trust exchange in an in-house audit, (2) Survey design and the
characterization of measurable trust attributes in energy audit processes, (3) Development
theoretical framework of audit process with practical cases, and (4) Developed an organizing
framework for audit coding.
7.2.1 Identification of value-trust exchange in an in-house audit
Home energy audits are typically performed as a technical service during an in-house
walkthrough, with most auditors emphasizing a common list of retrofits such as improving
insulation, repairing air leaks, and upgrading heating systems. Limited formal effort is placed on
learning techniques to build trust as a means to better encourage clients to make energy
improvements. Identification of value-trust exchange throughout the interactions between
homeowners and auditors reveals potential opportunities to address the shortcomings of existing
energy audit practices, as well as the improvement to the implementation rate of energy upgrades.
7.2.2 Survey design and the characterization of the measurable trust attributes in energy
audit process
This research applies both survey and audit recording to assess value-trust exchange
during the auditing process. The survey design of audit processes in a systematic way enabled
measureable indicators of trust exchange to be investigated and tested in the long term. Eight trust
attributes (“Competence”, “Customization”, “Reliability”, “Promptness”, “Similarity”,
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“Politeness”, “Empathy” and “Open and effective communication”) are identified based on the
literature in service industries and industry practice, and further characterized as survey questions
to evaluate audit processes. The statistical analysis of the survey responses reveals the possibility
to measure relationships between trust attributes and homeowner’s intention to implement energy
improvements as this measurable approach. The high survey response rate (76%) and data
collection methods indirectly confirm the survey created to assess homeowner’s level of trust of
energy audit is an effective instrument to evaluate audit processes.
7.2.3 Develop theoretical framework of audit process with practical cases
This research develops a series of models characterizing energy audit processes to
connect surveys and auditing recordings. Categorical variables of cost category, priority of
recommendations, constrain on energy improvements, and characteristics of homeowners are
used to evaluate audit processes. The framework developed in this research addresses both audit
processes and practical constraints on energy improvements. The framework is established as a
flexible model that enables analysis in multiple phases for variable objectives such as: (1)
measuring value-trust exchange of interactions between homeowners and auditors during in-
house walkthroughs, (2) investigate homeowners’ intention to implement energy improvements
while considering practical conditions and (3) provide feedback on audit process related to their
actions. The theoretical framework was found to be useful to evaluate value- trust exchange in
home energy audit process with the application of statistical technique to evaluate significant
variables
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Previous studies of energy auditing have approached auditing qualitatively. This research
categorizes audit processes and measures value-trust exchange interactions in a quantitative way,
which creates an opportunity to apply statistical analysis to study energy audit processes. Forty-
eight surveys are collected and analyzed. Key findings include the observation that homeowners
are more willing to enact energy upgrades in their home when they receive more customized
service and recommendations fit to their priorities and situational conditions and also when they
feel that they are being heard and responded to in a timely manner.
7.2.4 Developed an organizing framework for audit coding
In addition to the statistical analysis, this research develops and applies a coding
framework to identify audit processes as corresponded trust attributes. Using this coding,
researchers can identify the key interactions to specific types of value- trust exchange during an
audit, and track how much time spent on which trust attributes for cross-matching with
questionnaire data. This contribution will also enable training methods such as those employed
by the NELC to emphasize the development of trust, and also provide feedback to auditors on
their success in creating value-trust exchanges during the audit process. Analysis of recorded
audits revealed high-level indications that time spent on developing trust is a better predictor of
homeowners’ intention to act on improvements than the analysis of how and where time was
spent in variable zones of the home. This research also provides a foundation for the application
of trust evaluation between different parties in other sectors of the energy efficiency industry.
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Research Limitations and Future Research 7.3
The framework developed in this research was positively organized to investigate groups
of variables influencing energy improvements in different audits. The application of statistical
techniques helps to indicate significant variables for trust relationships between homeowners and
auditors, as well as the feasibility trust evaluation with post-audit survey and coding instrument.
This research encountered the limitations of shortage of data sample within specific regions.
However, there are opportunities to improve the framework in future research:
1) Develop a consistent methodology for measuring latent variables of energy audit.
The data collection mainly focuses on studying variable the connections between trust
relationships, constraints on energy improvements, and homeowners’ intention to
implement energy improvements. However, there are latent variables that require further
definition and classification, such as homeowners’ income, level of education…etc.
Expanding latent variables with a consistent classification will provides a more in-depth
understanding of audit processes, which may increase accuracy and enable better energy
audit service in the future.
2) Develop a follow-up studies to track energy improvements of each household. The
audits conducted as part of this research were well received and resulted in positive
feedback and high satisfaction with the NELC energy audits. However, the results
presented here are from relatively short-term tracking of homeowners’ intention to act.
The follow-up tracking of energy efficiency improvements in each household will
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strengthen the credibility of the value-oriented energy audit, as well as demonstrate
practical techniques to optimize energy audits.
3) Apply the techniques in this research to data collected from different regions. In-
field data collection is costly and time consuming – the forty-six questionnaires and thirty
in-house recordings were collected for this research using a regional network of
volunteers in the three regions of Pennsylvania. Expansion of the study to other regions
would eliminate possible climate related conditions and regional biases that might affect
the outcome of the study.
4) Variable methods of data collection vary the reliability of data. This research used
both survey questionnaires and audio recordings of audit walkthrough to collect
homeowners’ feedback and direct observational data for evaluating energy audit process.
The variable methods (email, post mail, and administrated in person) of data collections
may vary the reliability of data quality. In the future, a more consistent method of data
collection of survey responses from homeowners will increase the reliability of data and
the further data analysis.
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APPENDIX A – Coding instrument of in-house energy audit
Value Dimension - Subjective value for building trust relationship
Types of trust
attribute Value adding process Definitions
Stage / zone of audit
process
Similarity Share common interests with homeowners related to home improvement
Sharing the same value with homeowners helps to build trust relationships In-house Walkthrough
Empathy Demonstrate understanding to homeowners’ concerns and conditions
Possesses a “warm considerate and caring" attitude to make homeowners feeling more comfortable
In-house Walkthrough
Politeness Acknowledge and compliment homeowners' effort in improving homes
Acknowledge and compliment homeowners' work shows empathy and politeness to build trust relationships
In-house Walkthrough
Politeness Provide inspection in a polite manner Provide inspection in a polite manner shows respect to homeowners and helps to build trust relationships
In-house Walkthrough
Open and
effective communication
Provide a pre- audit interview with homeowner Pre-audit interview helps to learn homeowners' concerns, preference and priority, which helps auditors to customize HEA for them.
In-house Walkthrough
Open and
effective
communication
Apply worldview psychology to increase the
transparence of communication with homeowners
Learn homeowners' personality with the worldview psychology helps to initialize the
transparency of communication with homeowners In-house Walkthrough
Promptness Respond to homeowners' concerns and questions Actively respond to homeowners' concerns and questions help to build trust
relationships In-house Walkthrough
Promptness Complete tasks of an in- house walkthrough on schedule
Professional performance of in house walkthrough on schedule helps to build trust relationships with homeowners
In-house Walkthrough
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Value Dimension - Objective value for exchanging information
Types of trust
attribute Value adding process Definitions
Stage / zone of audit
process
Reliability Collect information with Ipad Application Collecting information with I Pad and the NELC application helps to accelerate the walkthrough process
In-house Walkthrough
Reliability Collect and analyze home's annual utility usage Annual utility demonstrates the homeowners living habits related to energy usage, learn how they use energy helps to eliminate energy waste
Report generation
Reliability Provide in-home energy audit as 3rd party Provide audit as the 3rd party helps to build trust relationship with homeowners without selling products
In-house Walkthrough
Reliability Record house conditions with pictures Record home conditions with pictures provide reliable resources to the future analysis In-house Walkthrough
Reliability Inspect house conditions with IR camera Detect air cracks and penetrations with IR camera provides reliable evidence for future improvement
In-house Walkthrough
Reliability Measure magnitudes of windows, doors or any
other penetrations of house
Knowing magnitudes of windows, door and penetrations of house helps to estimate the
energy saving in the future In-house Walkthrough
Reliability Provide upgrade incentives or governmental rebates and subsidies to homeowners
Provide creditable resources related to incentives and government rebates to homeowners helps to increase homeowners' investment on home improvements
In-house Walkthrough
Customization Provide multiple feasible EEM recommendations while detecting corresponded home issues.
Provide feasible recommendations for home improvements increase homeowners' indentations to take actions
In-house Walkthrough
Customization Customize online home energy profile and related resources of home improvements
Provide a customize energy profile keeps homeowner staying interest in home improvement
Self-improvement
Customization Respond to homeowner's main concerns, preference and retrofit priorities
Learn homeowner's main concerns, preference and retrofit priorities helps to provide the home improvements recommendations suits them.
In-house Walkthrough
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Customization Customize audit report based on homeowner's concerns, worldview and priorities
Customize energy report in responded to homeowners' concerns, worldview and priorities highly increase homeowners' motivation to take action
Report generation
Customization Schedule a meeting and delivery the audit report in person
Deliver and explain the audit report t to homeowners in person helps to understand their feedbacks and interests to take actions
Report delivery
Customization
Explain home improvement alternatives to homeowners
Provide feasible solutions based on homeowners situations increase the possibility for homeowners taking actions
In-house Walkthrough
Customization Identify home safety risks Identifying safety risks allows them to be addressed quickly and potentially in
conjunction with EEM's and valued by homeowners. Pointing them out can also help build trust.
In-house Walkthrough- Living Upgrade
Competence
Identify home health issues
Identifying health problem allows them to be addressed in conjunction with EEM's and
valued by homeowners. Pointing them out can also help build trust.
In-house Walkthrough-
Living Upgrade
Competence Identify energy efficiency issues Identifying energy inefficiency problem allows them to be addressed in conjunction with EEM's and valued by homeowners. Pointing them out can also help build trust.
In-house Walkthrough- Living Upgrade
Competence Identify home discomfort issues Sources of discomfort due to thermal conditions enable an improvement to energy efficiency, which is valuable to homeowners.
In-house Walkthrough- Living Upgrade
Competence Inspect home envelops for air infiltration issues Sources of infiltration result to a large (amount) percent of unwanted heat gain/loss and are addressed through air sealing. Air sealing is a service that can be acquired/provided
In-house Walkthrough - Building Envelope
Competence Inspect doors and windows for possible air sealing weatherization
Gaps between doors /windows and frame result in large amount of unwanted heat gain/ loss and are addressed through weather-stripping.
In-house Walkthrough - Building Envelope
Competence Identify windows/ doors issues for storm windows or upgrade
Single pane glass and uninsulated windows (doors) result in a significant (amount)
percent of unwanted heat gain/loss and are addressed through storm windows or upgrade.
In-house Walkthrough - Building Envelope
Competence Identify envelope penetrations for air sealing Sources of penetrations result in a large (amount) percent of unwanted heat gain/loss and are addressed through air-tightening
In-house Walkthrough - Building Envelope
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Competence Inspect wall systems that need air barriers Sources of conduction result in a significant (amount) percent of unwanted heat
gain/loss and are addressed through improvements of air barriers, which reduce both air
leakage and air convention.
In-house Walkthrough -
Building Envelope
Competence Inspect wall systems that need to add insulation Sources of conduction result in a significant (amount) percent of unwanted heat gain/loss and are addressed through adding suitable insulations
In-house Walkthrough - Building Envelope
Competence Inspect external air condition condensing units Attached bushed and dirty units result in inefficient operation, which consume more
energy than needed
In-house Walkthrough-
Heating/ Cooling
Competence Inspect the primary energy system Identify primary energy system helps to find critical energy consumption In-house Walkthrough- Heating/ Cooling
Competence Inspect home heating system Inefficient heating system consumes more energy than it is needed In-house Walkthrough- Heating
Competence Identify issues of distribution system for energy inefficiency
Leaky or uninsulated pipes/ductwork reduce heating performance. Sealing or insulating ductwork is an easy DIY and cost effective implementation.
In-house Walkthrough- Heating/ Cooling
Competence Inspect home cooling system Inefficient cooling system consumes more energy than it is needed In-house Walkthrough- Cooling
Competence Inspect water heater for energy inefficiency Inefficient water heater consumes more energy than it is needed; water heater jacket is an easy DIY and cost effective implementation.
In-house Walkthrough- Water Heating
Competence Inspect CO and smoke detector for safe hazards CO and smoke detectors are obligated to be installed by building code for preventing
safety hazards in homes
In-house Walkthrough-
Living Upgrade
Competence Inspect heating/cooling systems controls Programmable thermostat helps to reduce energy consumption by setting multiple
indoor temperature based on occupants living styles
In-house Walkthrough-
Living Upgrade
Competence Inspect exhaust ventilation Functional exhaust fan contributes to indoor ventilation, air quality and comfort In-house Walkthrough-Living Upgrade
Competence Inspect Radon Radon is a radioactive gas that causes cancer, you cannot see, smell or taste radon in your homes.
In-house Walkthrough-Living Upgrade
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Competence Identify water vapor and moisture issues of home Redundant moisture cause mold and damp feeling in your house. Attic ventilation or dehumidifiers are effective to improve it
In-house Walkthrough-Living Upgrade
Competence Identify vampire load for electricity waste
Vampire load refers to the electricity many gadgets and appliances waste just by being
plugged in, stopping leaking money from your wallet can be as easy as pulling a few plugs.
In-house Walkthrough-Living Upgrade
Competence Inspect water conservation measures Adopt water conversation products in your showering & bathing, landscaping, toilet
flushing and dish/clothes washing contribute to reduce water consumption in your home
In-house Walkthrough-
Water Heating
Competence Inspect light fixtures and light bulbs LED light bulbs and dimming controls contribute to customize comfort atmosphere in your home with less energy consumption
In-house Walkthrough-Lighting
Competence Inspect indoor appliances for energy inefficiency Inefficient and aged appliances involve potential safety hazards as well as unwanted energy consumption.
In-house Walkthrough-Appliances
Competence Identify aged refrigerator for energy inefficiency Aged refrigerator results in noise and energy waste, high efficient refrigerator contribute to keep food fresh with less energy consumption
In-house Walkthrough-Appliances
Competence Identify attic issues Water damage, leaks, seepages, cracks, and mold are among the most common attic
problems, an attic inspection can help you stop the damage spread rapidly to the rest of your home
In-house Walkthrough-Attic
Competence Inspect attic hatch for hatch air sealing and insulation
Unseal and uninsulated attic hatch result in a significant (amount) percent of unwanted heat gain/loss and are addressed through air sealing and insulation
In-house Walkthrough-Attic
Competence Inspect attic air sealing Attic cracks lead to a large (amount) percent of unwanted heat gain/loss and are addressed through air sealing.
In-house Walkthrough-Attic
Competence Inspect attic layer for adding insulation Sources of conduction result in a significant (amount) percent of unwanted heat gain/loss and are addressed through improvements to thermal envelope
In-house Walkthrough-Attic
Competence Inspect attic system for effective ventilation Functional attic ventilation leads to healthy indoor air quality with natural air circulation and save energy.
In-house Walkthrough-Attic
143
APPENDIX B – Statistical results of mode
Model A
Estimates of Fixed Effectsa
Parameter Estimate Std. Error df t Sig. 95% Confidence Interval
Lower Bound Upper Bound
Intercept -.170305 .344282 25.733 -.495 .625 -.878345 .537735
[EEMCategory=1] .317836 .084559 156.496 3.759 .000 .150812 .484860
[EEMCategory=2] .290335 .120793 159.566 2.404 .017 .051776 .528894
[EEMCategory=3] .248208 .085829 156.761 2.892 .004 .078678 .417738
[EEMCategory=4] .216506 .100850 155.772 2.147 .033 .017296 .415716
[EEMCategory=5] 0b 0
[Priorityofrecommendation=1] .018984 .070175 142.812 .271 .787 -.119732 .157700
[Priorityofrecommendation=2] .084920 .068677 138.994 1.237 .218 -.050866 .220706
[Priorityofrecommendation=3] .055636 .066905 138.605 .832 .407 -.076650 .187922
[Priorityofrecommendation=4] -.009839 .066093 137.248 -.149 .882 -.140531 .120853
[Priorityofrecommendation=5] 0b 0
[Worldview=1] -.041990 .081673 25.538 -.514 .612 -.210019 .126039
[Worldview=2] .121348 .109282 26.399 1.110 .277 -.103119 .345814
[Worldview=3] .024062 .114850 24.504 .210 .836 -.212718 .260843
[Worldview=4] 0b 0
[Gender=1] .027217 .065883 24.401 .413 .683 -.108641 .163074
[Gender=2] 0b 0
Saving_utility .004867 .065804 139.683 .074 .941 -.125233 .134967
ROI .238701 .051741 159.904 4.613 .000 .136517 .340885
Affordable_cost .102345 .035997 136.042 2.843 .005 .031159 .173530
Living_upgrade .074328 .038936 83.239 1.909 .060 -.003110 .151766
Information_Skill .092108 .028575 154.280 3.223 .002 .035659 .148556
Competence -.041025 .112402 24.328 -.365 .718 -.272846 .190796
Customization .023557 .093325 28.569 .252 .803 -.167439 .214552
Reliability .142783 .147493 26.795 .968 .342 -.159956 .445522
Promptness .080644 .131721 24.487 .612 .546 -.190930 .352217
Similarity -.086940 .127747 28.928 -.681 .502 -.348240 .174360
Politeness -.165152 .187465 24.421 -.881 .387 -.551708 .221404
Empathy -.043360 .064107 25.236 -.676 .505 -.175328 .088609
Likelihood -.204001 .094763 26.169 -2.153 .041 -.398727 -.009274
a. Dependent Variable: Weight.
b. This parameter is set to zero because it is redundant.
144
Model B
Estimates of Fixed Effectsa
Parameter Estimate Std. Error df t Sig.
95% Confidence Interval
Lower Bound Upper Bound
Intercept .486266 .350369 28.134 1.388 .176 -.231277 1.203810
[EEMCategory=1] .389096 .098093 175.996 3.967 .000 .195507 .582685
[EEMCategory=2] .325741 .141725 174.438 2.298 .023 .046024 .605458
[EEMCategory=3] .264484 .102791 175.955 2.573 .011 .061622 .467346
[EEMCategory=4] .198445 .122345 174.828 1.622 .107 -.043018 .439908
[EEMCategory=5] 0b 0
[Priorityofrecommendation=1] .254526 .083238 151.851 3.058 .003 .090072 .418981
[Priorityofrecommendation=2] .257075 .083592 151.597 3.075 .002 .091919 .422230
[Priorityofrecommendation=3] .170934 .082178 150.889 2.080 .039 .008565 .333302
[Priorityofrecommendation=4] .052932 .080750 150.154 .656 .513 -.106621 .212486
[Priorityofrecommendation=5] 0b 0
[Worldview=1] -.000918 .081450 26.426 -.011 .991 -.168210 .166374
[Worldview=2] .093839 .106214 26.064 .883 .385 -.124461 .312140
[Worldview=3] .113622 .116274 26.395 .977 .337 -.125209 .352453
[Worldview=4] 0b 0
[Gender=1] -.006426 .066290 26.514 -.097 .924 -.142559 .129707
[Gender=2] 0b 0
Competence -.075181 .113968 26.417 -.660 .515 -.309266 .158905
Customization .238125 .092353 28.574 2.578 .015 .049119 .427131
Reliability -.067044 .149489 28.944 -.448 .657 -.372810 .238722
Promptness .146224 .136107 28.085 1.074 .292 -.132540 .424988
Similarity .139663 .121071 26.064 1.154 .259 -.109172 .388499
Politeness -.242567 .190741 26.786 -1.272 .214 -.634082 .148948
Empathy -.059811 .062933 26.612 -.950 .350 -.189028 .069405
Likelihood -.155532 .095260 28.338 -1.633 .114 -.350558 .039494
a. Dependent Variable: Weight.
145
b. This parameter is set to zero because it is redundant.
Model C
Estimates of Fixed Effectsa
Parameter Estimate Std. Error df t Sig.
95% Confidence Interval
Lower Bound Upper Bound
Intercept -.897400 .196818 111.055 -4.560 .000 -1.287407 -.507394
[Worldview=1] -.028057 .080241 30.042 -.350 .729 -.191922 .135808
[Worldview=2] .092592 .110957 30.777 .834 .410 -.133773 .318957
[Worldview=3] -.003205 .099652 27.717 -.032 .975 -.207427 .201017
[Worldview=4] 0b 0
[Gender=1] .019019 .062986 29.102 .302 .765 -.109783 .147821
[Gender=2] 0b 0
[EEMCategory=1] .286048 .084547 162.453 3.383 .001 .119095 .453002
[EEMCategory=2] .307043 .120535 166.532 2.547 .012 .069070 .545017
[EEMCategory=3] .214865 .086347 161.304 2.488 .014 .044348 .385382
[EEMCategory=4] .170812 .101391 160.092 1.685 .094 -.029425 .371048
[EEMCategory=5] 0b 0
[Priorityofrecommendation=1] .044780 .070611 141.838 .634 .527 -.094807 .184367
[Priorityofrecommendation=2] .115168 .068830 138.669 1.673 .097 -.020924 .251261
[Priorityofrecommendation=3] .078018 .067308 137.397 1.159 .248 -.055076 .211113
[Priorityofrecommendation=4] .011886 .066682 134.333 .178 .859 -.119996 .143767
[Priorityofrecommendation=5] 0b 0
Saving_utility -.072426 .062281 131.556 -1.163 .247 -.195629 .050776
ROI .245121 .050927 167.972 4.813 .000 .144581 .345661
Affordable_cost .073017 .036051 150.352 2.025 .045 .001786 .144249
Living_upgrade .062763 .039617 98.192 1.584 .116 -.015853 .141380
Information_Skill .105224 .028951 166.618 3.635 .000 .048066 .162383
a. Dependent Variable: Weight.
b. This parameter is set to zero because it is redundant.
146
Model D
Estimates of Fixed Effectsa
Parameter Estimate Std. Error df t Sig.
95% Confidence Interval
Lower Bound Upper Bound
Intercept -.295990 .230673 45.479 -1.283 .206 -.760454 .168475
[Worldview=1] -.006392 .070139 32.204 -.091 .928 -.149225 .136441
[Worldview=2] .156860 .098286 33.423 1.596 .120 -.043008 .356727
[Worldview=3] -.020427 .086650 29.719 -.236 .815 -.197461 .156607
[Worldview=4] 0b 0
[Gender=1] .015939 .054844 31.157 .291 .773 -.095892 .127771
[Gender=2] 0b 0
[EEMCategory=1] .287483 .082183 165.837 3.498 .001 .125223 .449743
[EEMCategory=2] .259546 .116929 166.980 2.220 .028 .028696 .490395
[EEMCategory=3] .218954 .084049 165.278 2.605 .010 .053006 .384903
[EEMCategory=4] .190530 .098881 163.731 1.927 .056 -.004717 .385777
[EEMCategory=5] 0b 0
[Priorityofrecommendation=1] .026993 .069780 145.136 .387 .699 -.110922 .164909
[Priorityofrecommendation=2] .097591 .068141 142.114 1.432 .154 -.037111 .232293
[Priorityofrecommendation=3] .063424 .066567 141.023 .953 .342 -.068174 .195023
[Priorityofrecommendation=4] -.000655 .066005 138.270 -.010 .992 -.131165 .129855
[Priorityofrecommendation=5] 0b 0
Saving_utility -.032251 .060571 127.811 -.532 .595 -.152102 .087600
ROI .249702 .049062 165.539 5.090 .000 .152834 .346570
Affordable_cost .094707 .034553 138.071 2.741 .007 .026386 .163029
Living_upgrade .068325 .036639 84.842 1.865 .066 -.004526 .141176
Information_Skill .094355 .027800 159.825 3.394 .001 .039452 .149258
Likelihood -.221830 .058796 39.467 -3.773 .001 -.340710 -.102949
a. Dependent Variable: Weight.
b. This parameter is set to zero because it is redundant.
147
Model E
Estimates of Fixed Effectsa
Parameter Estimate Std. Error df t Sig.
95% Confidence Interval
Lower Bound Upper Bound
Intercept .746025 .302867 188 2.463 .015 .148571 1.343479
[Cost Category=1] .302802 .090433 188 3.348 .001 .124409 .481195
[Cost Category=2] .275094 .136147 188 2.021 .045 .006521 .543667
[Cost Category=3] .186643 .094890 188 1.967 .051 -.000543 .373829
[Cost Category=4] .131943 .111963 188 1.178 .240 -.088923 .352808
[Cost Category=5] 0b 0
[Priority of recommendation=1] .286057 .080323 188 3.561 .000 .127607 .444508
[Priority of recommendation=2] .287903 .080327 188 3.584 .000 .129445 .446360
[Priority of recommendation=3] .162050 .080086 188 2.023 .044 .004066 .320033
[Priority of recommendation=4] .063682 .079011 188 .806 .421 -.092180 .219544
[Priority of recommendation=5] 0b 0
Competence .017885 .104797 188 .171 .865 -.188844 .224614
Customization .285950 .091035 188 3.141 .002 .106368 .465532
Reliability -.001163 .132489 188 -.009 .993 -.262518 .260193
Promptness .160142 .112017 188 1.430 .154 -.060830 .381114
Similarity .311918 .140675 188 2.217 .028 .034414 .589422
Politeness -.261215 .173199 188 -1.508 .133 -.602879 .080449
Empathy -.041648 .053081 188 -.785 .434 -.146360 .063063
Overall trust level -.157665 .086664 188 -1.819 .070 -.328624 .013293
O&E Communication -.438554 .197762 188 -2.218 .028 -.828672 -.048436
a. Dependent Variable: Weight.
b. This parameter is set to zero because it is redundant.
148
Model F
Estimates of Fixed Effectsa
Parameter Estimate Std. Error df t Sig.
95% Confidence Interval
Lower Bound Upper Bound
Intercept -.008539 .306914 35.445 -.028 .978 -.631328 .614251
[Cost Category=1] .259171 .079903 168.772 3.244 .001 .101433 .416908
[Cost Category=2] .223278 .117575 170.831 1.899 .059 -.008809 .455365
[Cost Category=3] .181550 .081226 170.141 2.235 .027 .021209 .341890
[Cost Category=4] .152629 .095482 167.098 1.599 .112 -.035877 .341136
[Cost Category=5] 0b 0
[Priority of recommendation=1] .039294 .069189 150.712 .568 .571 -.097413 .176001
[Priority of recommendation=2] .095760 .067918 147.502 1.410 .161 -.038458 .229978
[Priority of recommendation=3] .034297 .065961 145.688 .520 .604 -.096066 .164661
[Priority of recommendation=4] -.007011 .065471 145.060 -.107 .915 -.136412 .122390
[Priority of recommendation=5] 0b 0
Saving utility .026655 .063470 157.286 .420 .675 -.098708 .152017
ROI .229926 .050828 170.406 4.524 .000 .129592 .330260
Affordable cost .097118 .033951 138.650 2.861 .005 .029989 .164247
Living upgrade .063188 .037762 98.703 1.673 .097 -.011744 .138119
Information/ Skill .094615 .027845 163.582 3.398 .001 .039633 .149597
Competence -.047020 .095704 31.114 -.491 .627 -.242181 .148140
Customization .017254 .089695 34.948 .192 .849 -.164847 .199355
Reliability .168485 .129340 34.855 1.303 .201 -.094128 .431098
Promptness .075824 .100625 28.808 .754 .457 -.130038 .281685
Similarity -.096793 .118161 38.729 -.819 .418 -.335849 .142263
Politeness -.226571 .172505 32.505 -1.313 .198 -.577737 .124595
Empathy -.017002 .055642 33.099 -.306 .762 -.130194 .096190
Overall trust level -.191402 .087004 33.827 -2.200 .035 -.368249 -.014555
149
Model G
Model Summary
S R-sq R-sq(adj) R-sq(pred)
0.379813 4.15% 0.00% 0.00%
Coefficients
Term Coef SE Coef T-Value P-Value VIF
Constant -1.21 5.95 -0.20 0.840
T_ Interview 1.72 5.99 0.29 0.775 520.05
T_Exterior 2.22 6.16 0.36 0.719 120.50
T_ Garage 2.03 5.81 0.35 0.727 47.63
T_ Basement 2.12 5.70 0.37 0.711 91.09
T_First Floo 2.01 6.05 0.33 0.740 158.32
T_Second Floor 0.88 6.02 0.15 0.884 133.39
T_Attic 2.47 6.11 0.40 0.687 41.09
Regression Equation
Weight = -1.21 + 1.72 T_ Interview + 2.22 T_Exterior + 2.03 T_ Garage + 2.12 T_ Basement
+ 2.01 T_First Floo + 0.88 T_Second Floor + 2.47 T_Attic
150
Relation I
Model Summary
S R-sq R-sq(adj) R-sq(pred)
0.401155 27.40% 25.33% 23.13%
Coefficients
Term Coef SE Coef T-Value P-Value VIF
Constant 3.687 0.114 32.26 0.000
T_Customization 4.59 1.04 4.42 0.000 1.11
T_Promptness -28.29 8.12 -3.48 0.001 1.19
T_Politness -4.25 1.15 -3.69 0.000 1.08
T_Communication 0.394 0.260 1.51 0.132 1.07
Regression Equation
Likelihood = 3.687 + 4.59 T_Customization - 28.29 T_Promptness - 4.25 T_Politness
+ 0.394 T_Communication
151
Relation J
Model Summary
S R-sq R-sq(adj) R-sq(pred)
0.389431 1.14% 0.00% 0.00%
Coefficients
Term Coef SE Coef T-Value P-Value VIF
Constant -0.15 6.01 -0.03 0.980
T_Competence 0.74 6.00 0.12 0.902 606.66
T_Customization 0.65 6.29 0.10 0.918 42.89
T_Reliability 1.54 6.18 0.25 0.803 45.62
T_Promptness 3.0 11.8 0.25 0.799 2.47
T_Similarity 1.90 7.15 0.27 0.791 7.04
T_Empathy -0.39 7.14 -0.05 0.957 4.54
T_Politness 1.30 6.44 0.20 0.841 31.60
T_Communication 0.71 5.95 0.12 0.905 590.50
T_NoValue 0.84 5.89 0.14 0.887 123.96
Regression Equation
Weight = -0.15 + 0.74 T_Competence + 0.65 T_Customization + 1.54 T_Reliability
+ 3.0 T_Promptness + 1.90 T_Similarity - 0.39 T_Empathy + 1.30 T_Politness
+ 0.71 T_Communication + 0.84 T_NoValue
152
APPENDIX C – SAMPLE AUDIT REPORT
153
154
155
156
APPENDIX D – SURVEY SAMPLES
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
APPENDIX E – IRB APPROVAL
176
Vita
Fu-Ju Wu
Fu-Ju Wu is a native of Taiwan and has worked in the Taiwan, China, and the United
States as a designer, architect, and researcher. She graduated from Chung-Yuan Christian
University with a bachelor’s degree in architecture and a minor in language studies in 2005 and
from Peking University with a master’s degree in architecture in 2008. Following graduation, she
worked in Beijing, China and Shenzhen, China as an architectural designer. In 2011, she traveled
to the United States to study construction management. In 2012, she earned a master’s degree
from the University of Washington and joined the doctoral program of the Department of
Architectural Engineering at the Pennsylvania State University.