design process study for the demonstration homes - Architectural ...

UTILITY-FOCUSED MARKET MODEL FOR 

ZERO ENERGY NEW HOMES: DESIGN 

PROCESS STUDY FOR THE 

DEMONSTRATION HOMES 

Prepared For: 

California Energy Commission 

Public Interest Energy Research Program 

Managed By: 

Architectural Energy Corporation 

Prepared By: 

ConSol 

PIER PROJECT REPORT 

Arnold Schwarzenegger 

Aug 2006 

Governor 

CEC-500-04-024

Prepared By: 

Architectural Energy Corporation 

Judie Porter 

Boulder, Colorado 

Contract No. 500-04-024 

Work Authorization No. (if applicable) 

ConSol 

Steve Vang, Project Manager 

Stockton, California 

Prepared For: 

California Energy Commission 

Public Interest Energy Research (PIER) Program 

Cheri Davis, 

Contract Manager 

Ann Peterson, 

Building End-Use Energy Efficiency Program 

Manager 

Nancy Jenkins, 

Office Manager 

ENERGY EFFICIENCY RESEARCH OFFICE 

Martha Krebs, Ph.D., 

Deputy Director 

ENERGY RESEARCH AND DEVELOPMENT 

DIVISION 

B. B. Blevins, 

Executive Director 

DISCLAIMER 

This report was prepared as the result of work sponsored by the 

California Energy Commission. It does not necessarily represent 

the views of the Energy Commission, its employees or the State 

of California. The Energy Commission, the State of California, its 

employees, contractors and subcontractors make no warrant, 

express or implied, and assume no legal liability for the 

information in this report; nor does any party represent that the 

uses of this information will not infringe upon privately owned 

rights. This report has not been approved or disapproved by the 

California Energy Commission nor has the California Energy 

Commission passed upon the accuracy or adequacy of the 

information in this report.

Preface 

The Public Interest Energy Research (PIER) Program supports public interest energy research 

and development that will help improve the quality of life in California by bringing 

environmentally safe, affordable, and reliable energy services and products to the marketplace. 

The PIER Program, managed by the California Energy Commission (Energy Commission), 

annually awards up to $62 million to conduct the most promising public interest energy 

research by partnering with Research, Development, and Demonstration (RD&D) 

organizations, including individuals, businesses, utilities, and public or private research 

institutions. 

PIER funding efforts are focused on the following RD&D program areas: 

• Buildings End-Use Energy Efficiency 

• Energy-Related Environmental Research 

• Energy Systems Integration 

• Environmentally Preferred Advanced Generation 

• Industrial/Agricultural/Water End-Use Energy Efficiency 

• Renewable Energy Technologies 

What follows is the final report for the Zero Energy New Homes contract, contract number 500- 

04-024, conducted by Architectural Energy Corporation. The report is entitled Utility-focused 

Market Model for Zero Energy New Homes: Design Process Case Study for the Demonstration Homes. 

This project contributes to the Buildings End-Use Energy Efficiency program. 

For more information on the PIER Program, please visit the Energy Commission’s Web site 

www.energy.ca.gov/pier/ or contract the Energy Commission at (916) 654-5164. 

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Preface i 

Table of Contents 

Abstract ............................................................................................................................................... iv 

Executive Summary........................................................................................................................... 1 

1.0 Introduction.......................................................................................................................... 3 

1.1. Objectives ........................................................................................................................ 4 

1.2. Building America Program........................................................................................... 4 

1.3. Building Industry Research Alliance........................................................................... 5 

1.4. Federal, State, and Utility Incentives........................................................................... 6 

2.0 ZEH Case Studies ................................................................................................................8 

2.1. Case Study # 1: Premier Homes – Premier Gardens (Rancho Cordova, California) 

and Premier Oaks (Roseville, California) ................................................................... 8 

2.2. Case Study #2: Clarum Homes – Vista Montana (Watsonville, California) and 

Shorebreeze (Palo Alto, California) ............................................................................. 19 

2.3. Case Study #3: Morrison Homes – Lakeside (Elk Grove, California) .................... 20 

2.4. Case Study #4: Treasure Homes – Fallen Leaf (Sacramento, California)............... 22 

2.5. Case Study #5: Pardee Homes – Soleil (San Diego, California)............................... 25 

3.0 Discussion on Case Studies................................................................................................ 28 

3.1. Advantages to the Builder ............................................................................................ 28 

3.2. Disadvantages to the builder........................................................................................ 29 

3.3. Lessons learned .............................................................................................................. 30 

4.0 Recommendations for the Energy Commission’s ZENHome Program...................... 33 

4.1. Cost and features............................................................................................................ 33 

4.2. Facilitate involvement of local government ............................................................... 33 

4.3. 1-kW requirement .......................................................................................................... 33 

5.0 Benefits to California........................................................................................................... 34 

6.0 References............................................................................................................................. 35 

7.0 Glossary ................................................................................................................................ 36 

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List of Figures 

Figure 1. BIPV example...........................................................................................................................13 

Figure 2. Comparison of electric bills for Premier Gardens and Cresleigh Rosewood September 

2004 ....................................................................................................................................................16 

Figure 3:.Comparison of June 05 electric bills Premier Gardens (ZEH) versus Cresleigh 

Rosewood (non-ZEH)......................................................................................................................17 

Figure 4. Comparison of July 05 electric bills Premier Gardens (ZEH) versus Cresleigh 


Figure 5. Comparison of August 2005 electric bills Premier Gardens (ZEH) versus Cresleigh 


Figure 6. ZEH features for Vista Montana and Shorebreeze .............................................................19 

Figure 7. Vista Montana publicity flyer ................................................................................................20 

Figure 8. ZEH features for Lakeside......................................................................................................21 

Figure 9. Lakeside - ZEH model ............................................................................................................22 

Figure 10. ZEH features for Fallen Leaf................................................................................................24 

Figure 11. Fallen Leaf sales center / model..........................................................................................24 

Figure 12. ZEH features for Soleil..........................................................................................................26 

Figure 13. Soleil plans..............................................................................................................................27 

List of Tables 

Table 1. Typical Title 24 features and ZENHome features analysis Premier Garden —Plan 2248 

w/options .........................................................................................................................................10 

Table 2. Comparison of Premier Gardens and Cresleigh Rosewood ...............................................15 

iii

Abstract 

To help address California’s critical issue of growing energy use and demand, the California 

Energy Commission under the Public Interest Energy Research Program has initiated a Zero 

Energy New Home Program. Zero Energy New Homes are intended to provide even greater 

energy reductions than those offered by 2005 Title 24 standards and produce only 1 kilowatt of 

electricity demand during the summer peak. One of the projects under this PIER program is the 

Utility-focused Market Model for Zero Energy New Homes. The overarching goal of this project 

is to develop a sustainable market model for building new zero energy homes. This market 

model integrates innovative energy efficient electric technologies with on-site electricity 

generation from photovoltaic panels and creates a larger role for electric utilities in marketing 

these innovative types of homes. 

To help guide the implementation of this project, this report documents best practices from 

other high-efficiency residential design projects, such as the U.S. Department of Energy’s 

Building America Program. As shown, builders that offer tracts of 100% Zero Energy Homes 

were able to sell all homes in record time despite a cost premium and gained significant benefits 

in terms of free national press coverage, while homeowners realized impressive average energy 

bill reductions. 

Keywords: zero energy home, zero energy new home, Building America Program, highefficiency 

home building, energy efficient home construction, ENERGY STAR, energy efficiency 

builder rebates, energy efficiency builder incentives, 2005 Title 24 standards, peak demand 

reduction 

iv

Introduction 

Executive Summary 

As California’s population steadily rises—along with the number of new homes built to meet 

the population’s needs—the state’s ongoing problems related to the cost and production of 

electrical power to meet demand, and especially the summer peak demand, continue to 

intensify. To help address the issue of growing energy use and demand, the California Energy 

Commission under the Public Interest Energy Research (PIER) Program has initiated a Zero 

Energy New Home (ZENHome) Program, which includes four projects. 

Purpose 

One of the projects under the PIER ZENHome Program is the Utility-focused Market Model for 

Zero Energy New Homes (Utility-focused Market Model for ZENHomes). The overarching goal 

of this project is to develop a sustainable market model for building new zero energy homes, 

which are intended to provide even greater energy reduction than those provided by 2005 Title 

24 standards and to produce only 1 kilowatt (kW) of electricity demand during the summer 

peak. This business model is based on integrating innovative energy efficient electric 

technologies with on-site electricity generation from photovoltaic (PV) panels and on creating a 

larger role for electric utilities in marketing sustainable homes. To help guide implementation of 

this project, this report documents best practices from other high-efficiency residential design 

projects, such as the U.S. Department of Energy’s (DOE’s) Building America (BA) Program. 

Project Objectives 

• Evaluate case studies of highly efficient residential design projects with PV systems built 

under the Building America program and assessing the elements that contributed to 

their successes and failures 

• Assess lessons learned from the BA Zero Energy Homes (ZEH) program—in areas such 

as construction protocols and practices, avenues to acquire incentives to lower builders’ 

cost, marketing and media exposure, collaborative partnerships, competitive sales, and 

enhanced reputation and positive exposure—to facilitate and improve upon the concept 

of ZENHomes under the Utility-focused Market Model for ZENHomes project 

• Provide recommendations to the Energy Commission to modify the goals of the Utilityfocused 

Market Model ZENHomes project as needed to ensure success within the 

context of real-world constraints 

Project Outcomes 

After assessing five case studies, the project team developed these findings: 

• Federal and utility energy efficiency rebates that lower the cost to builders to construct 

Zero Energy Homes are essential and should be continued. 

• Market activities from the ZEH support team resulted in national media coverage that 

generated hundreds of thousands of dollars of free publicity for builders—which they 

perceived as a major benefit. 

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• Homes in 100% ZEH projects sold just as well as comparable homes offered in non-ZEH 

projects. 

• ZEH support team partners provided builders innovative building design, energy 

efficiency design techniques, and best construction protocols. 

• Placing PV systems on the front of homes does not create an aesthetic barrier to 

homeowners, suggesting that PV panels can be sited wherever needed to provide the 

greatest energy benefits. 

• Energy bill analyses showed that ZEH use less energy than typical 2005 Title 24 homes 

and reduce peak demand. 

Recommendations 

The Utility-focused Market Model for ZENHomes project should consider the following 

recommendations as the project is implemented: 

• Collecting on rebates and incentives was a major challenge for builders. Support teams 

should handle rebate and incentive paperwork for builders. 

• Support team marketing efforts should continue, as the resulting free media coverage is 

a major incentive to builders. 

• It costs builders about $8,000 to $15,000 more per house to build to ZEH standards 

rather than to 2005 Title 24 standards. Therefore, builder incentives and rebates will play 

a critical role in convincing builders to construct to the ZENHome standards. 

• Local governments need to be brought on-board early in the process to mitigate 

inspection delays caused by lack of familiarity with ZENHome or energy efficiency 

construction practices and materials. 

• The 1-kW peak demand goal for the PIER ZENHome Program may be hard for large 

homes and homes in harsher climates to meet. Further study will examine this goal. 

Benefits to California 

Increasing the number of ZEHs in California would create major benefits for the state: 

• These homes have been shown to decrease energy use and peak demand, which in turn 

decreases the need for purchasing high-cost peak power and constructing new 

generation—potentially reducing energy costs for all ratepayers. 

• ZEHs are built to the very highest construction standards, and will therefore create a 

stock of quality, long-lasting homes in California. 

• Energy and peak reductions from each home will continue well into the future. 

• As the benefits of ZENHomes become more widely known and understood, these 

homes will create greater market demand for energy efficiency—thus proliferating the 

related energy and demand benefits. 

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1.0 Introduction 

As California’s population steadily rises—along with the number of new homes built to 

meet the population’s needs—the state’s ongoing problems related to the cost and 

production of electrical power to meet demand, and especially the summer peak demand, 

continue to intensify. To help address the issue of growing energy use and demand, the 

California Energy Commission under the Public Interest Energy Research (PIER) Program 

has initiated a Zero Energy New Home (ZENHome) Program, which comprises four 

projects, including the Utility-focused Market Model for Zero Energy New Homes 

(Utility-focused Market Model for ZENHomes). 

The overarching goal of the Utility-focused Market Model for ZENHomes project is to 

develop a sustainable market model for building zero energy new homes. According to 

the goals established by the California Energy Commission, ZENHome designs should 

provide the following benefits at a cost premium of no more than $5,000: 

• Electricity savings of 25% greater 2005 Title 24 standards 

• 70% annual electric bill reduction for homeowners 

• No more than 1 kW electricity demand during the summer peak 

These goals are aggressive for production homes, and will require creative thinking about 

the home as a system. However, it is important to realize that these are goals rather than 

absolute requirements. The technology base for this business model includes innovative 

and cost-effective combinations of energy efficiency devices coupled with on-site 

electricity generation from photovoltaic (PV) panels to reduce both electrical demand and 

consumption. (Note that while natural gas consumption is also reduced through these 

strategies, gas savings per se are not within the scope of this project.) 

The Utility-focused Market Model for ZENHomes also emphasizes developing the role of 

the electric utility in creating a sustainable market for ZENHomes. To this end, the project 

will evaluate the benefits that ZENHomes offer to utilities and create relationships 

between utilities and other market participants to promote a sustainable market. A key 

element to this process is the use of best practices from other high efficiency residential 

design projects, such as the U.S. Department of Energy’s (DOE) Building America (BA) 

Program, and assessing the elements that contributed to their successes and failures. 

At the federal level, DOE, through its BA program, has been promoting the concept of 

Zero Energy Homes (ZEH) for several years. Specifically, BA fosters energy efficient 

technology development and helps builders construct ZEHs, defined as homes that offer 

energy savings of at least 30% compared to the BA benchmark, which is less stringent 

than the 2005 Title 24 standards. More details on the BA program and similar efforts are 

provided below. 

For reference, California established Title 24 Energy Efficiency Standards for Residential 

and Nonresidential Buildings in 1978 in response to a legislative mandate to reduce 

California's energy consumption. Referred to as Title 24, these standards set the 

requirements for the energy efficiency of new residential construction in California and 

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are the baseline for the performance of new homes. The most recent update of these 

standards went into effect in 2005. 

1.1. Objectives 

The California Energy Commission decided to sponsor a Zero Energy New Homes 

program based on the successful federal BA program, but with more stringent 

requirements. The Utility-focused Market Model for ZENHomes project created under the 

Zero Energy New Homes program focuses on building sustainable markets ZENHomes, 

rather than on technology development. Therefore, this does not overlap or duplicate 

DOE’s current work, but rather, builds upon the existing research. 

This report documents the activities performed under the Utility-focused Market Model 

ZENHome project. For this project, the contractor will: 

• Evaluate case studies of highly efficient residential design projects with 

photovoltaic systems and assessing the elements that contributed to their 

successes and failures 

• Assess lessons learned from the federal ZEH program—in areas such as 

construction protocols and practices, avenues to acquire incentives to lower 

builders’ cost, marketing and media exposure, collaborative partnerships, 

competitive sales, and enhanced reputation and positive exposure—to facilitate 

and improve upon the concept of ZENHomes under the Utility-focused Market 

Model ZENHomes project 

• Provide recommendations to the Energy Commission to modify the goals of the 

Utility-focused Market Model ZENHomes project as needed to ensure success 

within the context of real-world constraints 

1.2. Building America Program 

The Building America program is a private/public partnership sponsored by DOE that 

conducts research to find energy-efficient solutions for new and existing housing that can 

be implemented on a production basis. The program combines the knowledge and 

resources of industry leaders with DOE’s technical capabilities to act as a catalyst for 

change in the home building industry. BA work focuses primarily on the development 

and integration of technologies into the ZEHs, development of rate structures to promote 

demand response, and development of controls to implement demand response. These 

activities focus on creating technology, rather than on creating markets. 

The BA program helps builders to build communities that will generate as much energy 

as they consume on an annual basis by the year 2010. Currently, seven BA teams are 

active across the nation, with each team responsible for certain climate zones. The 

Building Industry Research Alliance (BIRA) team, led by ConSol, is responsible for the 

marine and hot-dry climate zone which includes California. BIRA’s work with production 

builders to achieve this goal is discussed in the next section. 

DOE’s BA program uses a systems engineering approach to produce homes on a 

community scale that: 

4

• Reduce energy use by 40% to 70% 

• Reduce construction time and waste 

• Improves productivity 

• Provides new product opportunities 

• Implements energy-and material-saving technologies 

The goal of the BA teams is to increase the requirements each year to achieve an annual 

zero energy bill by 2010. A home can achieve a zero energy bill by building with today’s 

technology. However, such a home would be very expensive, and builders are reluctant 

to take this approach. The gradual approach of BA is a far more palatable proposition for 

builders, who can choose to build ZEHs in one of three ways: 

• As an option, leaving the sales agent to sell the benefits of ZEH 

• By building a designated number of pre-plotted lots to ZEH standards 

• By building the entire community to ZEH standards 

There are positive and negative impacts to these three options, which will be discussed in 

the case studies section of this report. 

1.3. Building Industry Research Alliance 

The Building Industry Research Alliance team, a diverse coalition of 31 industry partners, 

is the newest coalition to join the BA program. From its large BIRA membership, a core 

design-team will work with builder partners (and other interested builders) to develop 

and modify home plans to make them more resource efficient. The full BIRA team meets 

periodically to review progress and provide input and constructive criticism of the design 

team’s efforts and results. BIRA’s goal for the ZEH program today is to promote houses 

that reduce the total energy bill by at least 60% and produce as much electricity as they 

consume annually. BIRA core design team activities include the following: 

• Studying builder's market demographics 

• Performing systems analyses of home designs to optimize energy saving features 

and construction practices 

• Constructing prototype homes 

• Evaluating the design, construction practices, and operation of prototypes for cost 

and performance 

• Improving the design and construction practices in either additional prototypes or 

in full community implementation. 

Collaborating with builders, BIRA has overseen the construction of approximately 700 

ZEHs in California (including five ZEH communities), two ZEHs in Las Vegas, Nevada, 

and one ZEH in Oakridge, Tennessee. Some of these projects incorporate such innovative 

technologies as: 

• DOW’s T-Mass wall product, which effectively uses the thermal mass effect of 

concrete to create an “equivalent wall performance R-value” several times greater 

than that is estimated by a traditional material R-value calculation 

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• The structural insulated panel (SIP) wall system, an engineered panel for walls 

and roofs that provides structural framing, insulation, and exterior sheathing in a 

solid one-piece component 

• The optimal value engineering (OVE) wall system, a framing material that enables 

better insulation than is possible in a wood-frame house 

• Freus air conditioning (AC), a high-efficiency AC option 

• Attic radiant barriers, which reduce AC loads by reducing home heat gain 

• Solar water heaters 

• Photovoltaic systems 

• Tankless water heaters 

• OASYS Two Stage Evaporative Coolers 

• The NightBreeze System, which circulates cool nighttime air through a home to 

remove the heat stored during daytime hours in the home’s thermal mass, 

allowing comfortable home temperatures during the day with little or no AC 

needed 

• Radiant flooring 

Other BIRA-sponsored ZEH/BA projects are underway in Arizona, Colorado, 

Washington, Texas, Nevada and California. These homes are in the planning stages and 

will include monitoring equipment to measure the energy performance of the various 

technologies. 

1.4. Federal, State, and Utility Incentives 

As of 2006, the following federal tax credits are available: 

• $2,000 to the builder for building 50% above the 2004 International Energy 

Efficiency Code (IECC) 

• $2,000 to the buyer for installing a PV system on the home 

• $300 to the builder for installing a tankless water heater 

At the state level, the California Energy Commission provides a rebate of $2.60 per watt 

(W) for qualified PV systems through its Emerging Renewables Program (ERP). The ERP 

is open to customers of investor-owned utilities only and applies to systems under 30kW. 

This rebate level is as of August, 2006 and will be reduced over time. Meanwhile, the 

California Public Utilities Commission (CPUC) provides incentives to systems over 30kW 

through the Self-Generation Incentive Program (SGIP). 

The ERP and SGIP are to be replaced by new solar incentive programs in 2007. The CPUC 

and Energy Commission are jointly working on implementation of the California Solar 

Initiative (CSI), a 10-year, $2.9 billion program designed to move California citizens 

toward a diversified energy future. The program also will help reduce the costs of solar 

electricity through incentives. One of the program’s components focuses on incentives for 

PV systems installed on new homes. The California Energy Commission is responsible for 

implementing the new home component of the CSI program (currently called the “New 

Solar Homes Partnership), which runs from 2007 through 2017. 

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In addition, utilities typically have other incentives for building ZEH and participating in 

demand-side management programs. However, these are limited and are constantly 

changing. It is important to note that the builder can apply only for one rebate/incentive 

from the ERP or the utility, but not both. 

Some municipal utilities (also called publicly owned utilities) also provide incentives for 

incorporating PV systems. In the greater Sacramento area, two municipal utilities, 

Roseville Electric and Sacramento Municipal Utility District (SMUD), offer incentives for 

energy-efficient homes and for the installation of residential PV systems. The Roseville 

Electric incentives as of August, 2006 are as follows: 

• $4/watt for PV buy down 

• $600/house for meeting the Platinum Advantage Home program 

The SMUD incentives as of August, 2006 are as follows: 

• $20,000 for marketing 

• $3.00/watt for PV buy down 

• $500/house for line extension refund 

• $200/house for using fluorescent lamps and building to ENERGY STAR® home 

standards 

Builders featured in the following case studies took advantage of incentives, primarily 

from Roseville Electric and SMUD, to offset the initial costs of PV systems for their ZEHs. 

7

2.0 ZEH Case Studies 

2.1. Case Study # 1: Premier Homes – Premier Gardens (Rancho Cordova, 

California) and Premier Oaks (Roseville, California) 

Premier Homes builds an average of 70 to 90 new homes a year in the Sacramento region. 

Prior to the Premier Gardens project discussed below, Premier had built two homes with 

PV systems, offering the PV as standard in both. A sister company, also owned by 

Premier, installed the systems. 

It is interesting to note that owners of the Premier Homes company have exhibited a 

personal interest in renewable energy by supporting these first experiments, starting and 

supporting a solar installation company, and installing PV systems on the homes they 

build. 

2.1.1. Deciding to make ZEH standard in Premier Gardens 

BIRA, SMUD, and GE Energy approached Premier Homes with the concept of offering 

ZEHs in Premier’s development in Rancho Cordova, a southeast suburb of Sacramento 

that is within SMUD’s service territory. The team proposed that Premier Homes build 

new homes with PV systems and energy efficiency features that would save homeowners 

about 60% on electric bills as standard features in their planned community of 94 homes. 

The project included five plan types and the floor area ranged from 1,285 square feet (ft2) to 2,394 ft2. Premier was aware of the marketing success of other ZEH builders in California and was 

particularly impressed that SMUD was committed to supporting the project, not only by 

providing financial and marketing support, but also by offering assistance from their staff. 

Premier decided to become the first builder to “bring the first standard zero energy 

community to Sacramento.” 1 

Premier Homes chose to build ZEH as standard offerings at Premier Gardens for the 

following reasons: 

• To gain more experience with innovative homebuilding technologies, PVs in 

particular 

• To differentiate themselves, attract attention, and consequently sell homes more 

quickly 

• Because available incentives would decrease the financial burden 

• To offer ZEHs as a standard package and make it affordable for entry level 

homebuyers while other builders only offer ZEH as a move-up option 

• To promote innovative construction and energy efficiency, be energy conscious, 

and “do good” for the community 

Premier Homes wanted to differentiate themselves from other builders. Having built a 

few other projects in Northern California with photovoltaic systems, the company wanted 

1 John Stewart, President and Co-Owner, Premier Homes. Declaration at the Grand Opening of Premier 

Gardens, April 21, 2004. 

8

to continue to build more homes with cutting-edge technology. Premier Homes also 

wanted to promote energy efficiency, bring value to the already established Rancho 

Cordova neighborhood, and “to design and to save entry-level homebuyers up to 60% on 

utility costs and conserve energy for the good of the environment.” 2 

Premier Homes understood that building energy efficient homes that produce their own 

electricity is good for the community because “ZEHs will lower energy bills for 

homeowners and will reduce energy demand on hot summer days when electricity is 

most expensive and the power grid is most utilized.” 3 They felt that perhaps this 

community could contribute to preventing the rolling blackouts that California 

experienced the few years prior. 

2.1.2. Premier Gardens features 

The ZEH/Building America features for Premier Gardens are as follows: 

• Wall insulation of R-13 batt with 1-inch foam insulation (one-coat stucco system) 

• Tight envelope with low air infiltration: specific leakage area (SLA) = 3.5 or less 

(inspection and testing by third-party certified inspectors) 

• Dual pane vinyl frame with spectrally selective glass 

• Highly energy efficient furnace of 0.91 annual fuel utilization efficiency (AFUE) 

• Highly energy efficient AC of 14 seasonal energy efficiency ratio (SEER) with 

thermostatic expansion valve (TXV) 

• R-4.2 duct insulation buried in attic insulation, producing R-13 equivalent 

• Tight duct system designed by a licensed mechanical engineer using Air 

Conditioning Contractors of America (ACCA) Manual D 

• Tankless water heater with an energy factor (EF) of 0.82 

• R-4 pipe insulation on all major hot water trunks 

• Gas dryer 

• Fluorescent lighting at all downlights 

• 2.4 kW DC PV system by GE (building integrated panels to blend in with roof 

tiles) 

Table 1 compares the typical Title-24 construction features with the ZEH measures. 

2 John Ralston, VP of Marketing, Premier Homes. 

3 John Stewart, President and Co-Owner, Premier Homes. 

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ENVELOPE (insulation R-values) 

Table 1. Typical Title 24 features versus ZEH 

Premier Gardens —Plan 2248 w/options 

10 

Base T-24 House ZEH Features 

Roof (attic) 38 38 

Roof (at furnace) 19 19 

Wall 13 (2x4) / 19 (2x6) 

Wall (garage) 13 13 

Floor (above garage/ cantilever) 30 30 

Attic radiant barrier No Yes 

Low air infiltration Yes Yes 

Quality installation of insulation credit Yes Yes 

GLAZING 

U-Factor 

Slider (horizontal) 0.40 0.37 

Slider (vertical) 0.40 0.37 

Fixed 0.40 0.33 

Patio 0.40 0.34 

SHGC 4 

Slider (horizontal) 0.43 0.32 

Slider (vertical) 0.43 0.32 

Fixed 0.43 0.35 

Patio 0.43 0.34 

HVAC SYSTEM (tonnage) 4.5 3.5 

Furnace: AFUE 0.80 0.91 

13 + R-4.2 (2x4) / 

19+R-4.2 (2x6) 

A/C: SEER 13 14 TXV SEER 

4 Solar Heat Gain Coefficient

Duct insulation/location R-4.2 

11 

Base T-24 House ZEH Features 

Duct testing Yes Yes 

ACCA Manual D Yes Yes 

WATER HEATING 

R-4.2 (buried in 

insulation) 

Water heater size 50 gal Tankless 

Energy factor 0.60 0.82 

Distribution type Standard Pipe Insulation 

PV SOLAR ELECTRIC 

PV solar electric system None 2.4 kW DC PV 

MISCELLANEOUS 

3rd-party inspections and testing Yes 

Gas dryer stub Yes 

Fluorescent lighting 2005 package 2005 package 

With the ZEH features listed above, the design plan for the largest home (referred to as 

Plan 2248 with options) shows an energy savings of 61% over the 2001 Title 24 baseline 

house. Using the Micropas 5 hourly simulation software, an energy analysis tool to 

evaluate California Title 24 compliance, the team estimated the following energy benefits: 

• Offers 37% greater energy efficiency than the 2005 Title 24 baseline house 

• Reduces annual electric bills by 96% compared to a typical home 

• Consumes 0.4 kW from the utility grid during peak time (based on SMUD’s 

system peak day of July 14 th at 5:00 PM), as compared to the base Title 24 house 

that draws 2.3 kW 

Appendix A contains the peak analysis and comparison of total energy use for this design 

plan. 

2.1.3. Deciding to make ZEH standard in Premier Oaks 

Premier Gardens was such a huge success—in terms of both sales and the positive PR 

generated--that Premier Homes decided to build another ZEH community of 29 homes 

called Premier Oaks in Roseville, California, 30 miles northwest of Rancho Cordova. This 

5 Micropas is a product of Enercomp, Inc.

project, which sold out before the homes were built out, was supported by team 

composed of BIRA, GE Energy, and Roseville Electric. The building features are the same 

as those at Premier Gardens. 

2.1.4. Risk management 

The unique responsibilities placed on the owners of ZEHs narrow the pool of likely 

customers for these homes. ZEH owners must establish a different type of relationship 

with their electric utility, that of being an electric generator to the utility. Homes with PV 

must have interconnecting equipment that links their homes to the utility grid in a 

different way and safety features not required by conventional homes. In addition, 

homeowners with PV homes must sign Interconnection Agreements with their electric 

utility. 

Premier viewed this new, uncharted territory as a potential risk they needed to manage 

carefully. For this reason, Premier was very interested in SMUD’s promised educational 

campaign to explain the SMUD Interconnection Agreement to Premier management, sales 

staff, and home buyers. Premier found SMUD’s commitment and delivery very 

responsive. SMUD’s commitment was a key factor in Premier’s decision to build 100% of 

their homes in Premier Gardens as ZEHs. Premier found a similar level of service offered 

by Roseville Electric for their second ZEH community, Premier Oaks, in Roseville, 

California. 

2.1.5. Pricing 

A big part of managing risk for homebuilders is assessing the price range in particular 

locations. Adding solar electric systems and high-efficiency energy features into the mix 

of other new home offerings increases an already complex decision-making process. 

With PV systems as a standard feature in Premier’s communities, price and consumer 

value had to be carefully balanced. Premier had to decide which features—such as marble 

countertops—they would remove from their standard offerings and present instead as 

options. 

As a result of their experience in the Premier Gardens and Premier Oaks communities, 

Premier is now studying price ranges for developments planned in the next 6 to 18 

months. They foresee that some developments are more likely than others to bear the cost 

of incorporating PV. In developments where ZEH is not offered as a standard, they plan 

to offer PV as an option. 

2.1.6. Integrated PV systems 

In its first two PV homes, Premier used General Electric’s (GE) Gecko system and has 

been comfortable with the aesthetics of this building-integrated PV (BIPV) system and 

with home buyer acceptance of the installation. BIPV systems integrate seamlessly into 

the roof tiles (see Figure 1). Some homebuilders and architects are hesitant to install PV 

systems on the front view of homes. However, others believe that the visibility of wellintegrated 

PV systems is desirable by homebuyers. Premier continues to specify roofintegrated 

systems, even on the front of the houses. 

12

Figure 1. BIPV example 

As a key requirement, BIPV systems must be sited in a southern direction between east 

and west orientations to optimize performance. A PV system generates the most kilowatthours 

(kWh) per year at the south orientation and may produce up to 15% less for either 

east or west orientations. The PV systems at Premier Gardens are installed in all three 

(south, east, and west) orientations. Another critical requirement is to ensure that PV 

panels are not shaded by trees or other structures. 

2.1.7. Advantages to Premier Homes 

Five major benefits contributed to Premier Home’s decision to build ZEH communities, 

each of which is discussed in more depth below: 

• Utility incentives/rebates 

• Marketing and media success 

• Collaborative partnerships 

• Competitive sales 

• Enhanced reputation and positive exposure 

2.1.8. Utility incentives/rebates 

Premier Homes qualified for utility incentives for the Premier Gardens and Premier Oaks 

communities. It is important to note that both incentive programs required the installation 

of PV systems and energy efficiency features in the homes for the builder to qualify. 

The Roseville Electric rebates for Premier Oaks were as follows: 

• $4/watt for PV buydown ($8,825/house) 

• $600/house for meeting the Platinum Advantage Home program 

13

The SMUD rebates for Premier Gardens in Rancho Cordova follow: 

• $20,000 for marketing 

• $3.50/watt for PV buy down 

• $500/house for line extension refund 

• $200/house for using fluorescent lamps and meeting ENERGY STAR 

2.1.9. Marketing and media success 

Before construction started, there were numerous articles about Premier Gardens in local 

newspapers and in home and garden magazines describing its energy efficiency. On April 

21, 2004, Premier Homes completed three models and had their grand opening ceremony 

where they were interviewed by three Northern California television news stations. 

Premier Homes believed this media coverage was very successful and provided valuable 

exposure of both Premier Homes and Premier Gardens to the community. The entire 

energy efficiency expert team attended the grand opening, including guest speakers such 

as Robert Rivinius, CEO of the California Building Industry Association, who gave high 

praise to Premier Homes for voluntarily building the first ZEH community. Other 

exposure included coverage on Northern California television evening news and the Good 

Morning America show, as well as in local newspapers, trade journals, and Newsweek. Since 

its grand opening, Premier Gardens has enjoyed continuous positive press and has been 

visited by builders, engineers, architects, and dignitaries from the United States and 

abroad. 

The homes at Premier Gardens sold very well, presumably due to the press and 

marketing assistance of the ZEH, ENERGY STAR, SMUD Advantage, and ComfortWise 

programs. Brief descriptions of these programs are provided in Appendix B. 

2.1.10. Collaborative partnerships 

Premier Homes increased its involvement with non-profit business and governmental 

organizations by building ZEHs. Collaborating organizations included ConSol, SMUD, 

City of Rancho Cordova Building Department, the DOE BA and ZEH Programs, National 

Renewable Energy Lab (NREL), the California Energy Commission, GE, and Rinnai 

Corporation. 

These partners provided innovative building design and energy efficiency design 

techniques. They also provided the best construction protocols and ensured the homes 

were built, tested, and inspected with the highest standards. The team also helped make 

Premier Homes a leader in building with energy efficiency and renewable technology. 

2.1.11. Competitive sales 

Premier Homes offered ZEH as a standard package in the Premier Gardens community 

and experienced positive sales results. The Premier Gardens homes were sold-out before 

they were built-out, even with Cresleigh Homes (a competitor development) building 

homes adjacent to them. This adjacent community offered an opportunity to evaluate the 

ZEH development against a comparable, non-ZEH offering. Several variables from the 

two communities are compared and discussed in this section. 

14

Both Premier and Cresleigh constructed 94 similarly sized homes. The Premier Gardens 

homes were ZEH and the Cresleigh Homes were ENERGY STAR and included features 

such as granite countertops as standard. (See Table 2 for a comparison of key features.) 

Premier Homes began construction approximately one month later than Cresleigh but 

sold out at the same time. The home prices ranged from $300,000 to $476,000. During the 

construction phases, both builders raised their prices four to five times, yet had no 

problems selling the homes. The incremental cost to Premier Homes for the ZENHome 

design package was approximately $10,000 per home after rebates. This cost was passed 

on to the homeowner as a mark up. 

The following section compares the neighboring communities of Premier Gardens and 

Cresleigh Rosewood. The homes built in both of these developments are approximately 

the same size and have similar energy features. The small differences are that the 

Cresleigh homes are slightly larger and Premier Gardens homes are more energy efficient 

in a few areas and include PV systems. Table 2 summarizes the two developments. 

Table 2. Comparison of Premier Gardens and Cresleigh Rosewood 

Home builders Premier Gardens Cresleigh 

Energy program ComfortWise SMUD Advantage Home 

Square footages 2,248 2,384 

1,846 2,024 

1,625 2,000 

1,285 1,850 

15 

1,720 

1,610 

Photovoltaics 2kW AC GE None 

Air Conditioner 14 SEER 10 SEER 

Heating Efficiency 91% 80% 

Water heating Tankless 82% EF 40 Gallon 

Ceiling Insulation R-38 R-30 

Wall Insulation Insulation wrap w/ stucco R-17 w/Tyvek wrap 

Windows Vinyl Low-E E-squared vinyl

Comparison of Electric Bills 

Figure 2 below compares the electric bill for Premier versus Cresleigh Homes for the 

month of September 2004. In Figure 2, the largest electric bill in both developments is 

compared to one another, and the next largest, and so on. The average Cresleigh energy 

bill during this period is $66.68 while the average Premier energy bill is 70% less at $19.99, 

and bills for some homes actually becomes negative. While energy use is dependent on 

many factors, including the occupant habits, these data show a dramatic difference in 

energy costs. This difference is primarily due to the savings from the PV systems, in 

addition to the energy efficiency features. 

Figure 2. Comparison of electric bills for Premier Gardens and Cresleigh Rosewood 

September 2004 

Figures 3 through 5 compare the ZEH versus non-ZEH electric bills for the months of 

June, July, and August 2005. For each month, the total electric bill (in dollars) is displayed 

in decreasing magnitude for each of the homes. The average monthly cost for the ZEHs 

and the non-ZEHs are overlaid for comparison. Overall, the electric bills at Premier 

Gardens are much lower than those of the non-ZEH community. SMUD publicized these 

results on numerous occasions and on the Good Morning America show in August 2005. 

16

$250 

$240 

$230 

$220 

$210 

$200 

$190 

$180 

$170 

$160 

$150 

$140 

$130 

$120 

$110 

$100 

$90 

$80 

$70 

$60 

$50 

$40 

$30 

$20 

$10 

$0 

-$10 

-$20 

-$30 

$310 

$285 

$260 

$235 

$210 

$185 

$160 

$135 

$110 

$85 

$60 

$35 

$10 

-$15 

-$40 

Solar Home bill is 55 % lower than the typical SMUD bill and 60% lower than the Neighboring homes right across 

the street. 

Solar June 05 Bill Non Solar June 05 Bill 

Solar Avg June 05 Bill NonSolar June 05 Bill 

Non Solar Avg June Bill $80.90 

Electric Bills 

17 

Solar Avg June Bill $32.71 

Figure 3:.Comparison of June 05 electric bills 

Premier Gardens (ZEH) versus Cresleigh Rosewood (non-ZEH) 

Solar Home bill is 1 % lower than the typical SMUD bill and 51% lower than the Neighboring homes right across 

the street. 

Non Solar Avg July Bill $148.03 

123456789101 121314151617181920212 232425262728293031323 343536373839404142434 454647484950515253545 565758596061626364656 6768697071727374757677879808182838485868788 909192 


ZEH JuLy 05 Bill Non-ZEH JuLy 05 Bill 

ZEH Avg JuLy 05 Bill Non-ZEH JuLy 05 Bill 

Solar Avg July Bill $72.06 

Figure 4. Comparison of July 05 electric bills 

Premier Gardens (ZEH) versus Cresleigh Rosewood (non-ZEH)

$280 

$260 

$240 

$220 

$200 

$180 

$160 

$140 

$120 

$100 

$80 

$60 

$40 

$20 

$0 

-$20 

-$40 

ZEH bill is 44% lower than the typical SMUD bill and 53% lower than the Neighboring homes right across the street. 

Non ZEH Avg Aug Bill $87.78 

1 11 21 31 41 51 61 71 81 91 


18 

ZEH Aug 05 Bill Non ZEH Aug 05 Bill 

ZEH Avg Aug 05 Bill Non ZEH Aug 05 Bill 

ZEH Avg Aug Bill $41.01 

Figure 5. Comparison of August 2005 electric bills 

Premier Gardens (ZEH) versus Cresleigh Rosewood (non-ZEH). 

2.1.11.1. Enhanced reputation and positive exposure 

Participating in the ZEH program played a major role in enhancing the reputation of 

Premier Homes as not only a quality builder, but also a builder with a vision to “do good” 

for the environment and the community. 6 After the first summer, the electric bills from 

the utility (SMUD) certainly proved that the homes were energy-efficient. 

The homes at Premier Gardens use quality construction to achieve both comfort and 

energy efficiency. In addition to benefiting from numerous press releases, John Ralston, 

Vice President of Marketing at Premier Homes, was interviewed on August 2005 by the 

Good Morning America show about the ZEH features and the low utility bills at Premier 

Gardens. The entire community was highlighted, along with homeowners explaining 

some of the ZEH features and their low energy bills. 7 In addition, Premier Homes won 

second place (silver) in the Energy Value Housing Award for 2005 for this project, 

enhancing their reputation from that of a small quality builder to that of a nationally 

known ZEH builder. 

6 Mike Keesee. SMUD. 2005 

7 Good Morning America. August 2005.

2.2. Case Study #2: Clarum Homes – Vista Montana (Watsonville, California) and 

Shorebreeze (Palo Alto, California) 

Clarum Homes builds an average of 200 new homes in Northern California’s Bay Area a 

year. Clarum began its green building program in 1999, with energy efficiency features 

and sustainable building materials as standard equipment on all homes. Clarum’s 

participation in the DOE ZEH initiative capitalized on the company’s previous experience 

with renewable energy. 

Working with the NREL and BIRA, Clarum decided to build all 257 homes at Vista 

Montana in Watsonville with solar electric panels in August 2003. These homes—which 

ranged in size from 1400 ft 2 to 2500 ft 2—were designed to save at least 50% on energy 

bills. This was the largest ZEH community in the United States at the time, and included a 

combination of apartments, townhomes, and single-family detached units. The PVs were 

installed only on the townhomes and single-family detached units. However, Clarum also 

installed a 60 kW DC PV system to serve such common areas as parking lots, recreation 

buildings, laundry rooms, and hallways. 

This project was scheduled to be completed in three years. However, it was so successful 

that the homes were built out and sold out in 1.5 years. “We have shifted our entire 

company mission and business plan to build nothing other than Zero Energy Homes from 

this point forward” states John Suppes, Vice President of Clarum Homes. 

Using the same ZEH features, Clarum also built another 29-home ZEH community called 

Shorebreeze in Palo Alto, California. The ZEH features for Vista Montana and 

Shorebreeze are shown in Figure 6, and Figure 7 shows a publicity flyer for Vista 

Montana. 

Figure 6. ZEH features for Vista Montana and Shorebreeze 

19

Figure 7. Vista Montana publicity flyer 

Clarum Homes is currently building these ZEH projects: 

• Borrego Springs in Borrego Springs, California (climate zone 15). These homes have an 

average size of 1645 ft 2 and feature four different wall systems, including Dow’s T- 

Mass wall, SIP panels, and the OVE wall system. These homes will also 

incorporate four different heating, ventilation, and air conditioning (HVAC) 

systems (two OASYS two-stage evaporative coolers, an 18-SEER Lennox HVAC 

system, and a Freus AC unit). 

• Vista Verde Project in Blythe, California (climate zone 15). This is an 80-home ZEH 

community with home sizes ranging from 1500 ft 2 to 2800 ft 2. These homes will use 

the SIP wall panels with high energy efficiency HVAC systems. 

• Pajaro Vista in Watsonville, California (climate zone 3). This is a 120-home ZEH 

community with home sizes ranging from 1300 ft 2 to 1600 ft 2. The features are the 

same as Vista Montana. 

Clarum is also planning to build five other ZEH communities in California in 2007, with 

or without rebates. According to John Suppes, they are only building ZEHs in the future. 

2.3. Case Study #3: Morrison Homes – Lakeside (Elk Grove, California) 

Morrison Homes in the Sacramento area builds approximately 90 homes per year. In their 

Lakeside project located in Elk Grove, California, they pre-plotted 10% (or 12 homes) to 

incorporate GE (formerly AstroPower) solar electric panels. The size of these homes 

ranged from 2100 ft2 to 3200 ft2. The 12 ZEHs offer a whole-house energy reduction of at least 60% compared to a Title 24 

home. “Morrison’s goal is to improve homebuilding technology, reduce operating costs 

for our homeowners, and help minimize the impact of homebuilding on our 

environment,” said Bob Walter, President of Morrison Homes. Although the homeowners 

paid a premium of $18,000 for a ZEH, the overall price was still comparable for the area, 

according to Morrison Homes. The average price for the ZEH and non-ZEH was in the 

20

mid $300,000, and the ZEHs sold just as well as the non-ZEHs. Monitoring equipment 

was also installed in four of the homes to track performance. 

This project was supported by the DOE ZEH program, SMUD, and the City of Elk Grove. 

The project gained national attention and appeared in numerous evening news shows, 

local papers, trade journals and radio stations. Rebates for this project included the 

following: 

• $500 SMUD hook-up fee rebate 

• $200 from SMUD to build at the ENERGY STAR level 

• $4/watt from SMUD for PV solar buydown 

Morrison Homes participated in the ZEH program for the following reasons: 

• To gain more experience with innovative homebuilding technologies and with 

PVs in particular 

• To differentiate themselves, attract attention, and thus sell homes more quickly 

• To take advantage of incentives 

Figure 8 shows the energy features for Lakeside, and Figure 9 shows marketing material 

for the homes. 

Figure 8. ZEH features for Lakeside 

21

Figure 9. Lakeside - ZEH model 

2.4. Case Study #4: Treasure Homes – Fallen Leaf (Sacramento, California) 

Treasure Homes is currently building a 32-home ZEH project in Sacramento, California. 

The homes sizes range from 1026 ft2 to 2271 ft2 and the home prices are from $350,000 to 

$489,000. Again, they are supported by the DOE ZEH program and SMUD. These homes 

are designed to have an annual energy savings of 60% compared to a typical Title 24 

house. The rebates the project is receiving are as follows: 

• $300 for installing tankless water heater (federal) 

• $500 SMUD rebate off hook-up fee 

• $200 from SMUD to build to the ENERGY STAR level 

• $3/watt buydown for PV solar from SMUD 

• $2,000 federal tax credit for installing a PV 

The incremental cost without rebates is approximately $22,000 and with rebates is roughly 

$12,000. Phil Barnes, President of Treasure Homes, stressed that they have “always been 

building with high efficiency measures to do good for the environment, and this would be 

a great opportunity to build ZEH in their Fallen Leaf project.” In addition, Barnes also 

mentioned that one of the deciding factors for building 100% ZEH was due to the ZEH 

team support and the following reasons: 


particular 


• Because rebates would decrease the incremental costs 

22

The Fallen Leaf project just completed its models and is now building the first production 

phase. 

Figure 10 summarizes the features of Fallen Leaf, and Figure 11 shows a Fallen Leaf 

home. 

FALLEN LEAF AT RIVERBEND 

SUMMARY OF ENERGY CONSERVATION AND TECHNOLOGY STANDARD FEATURES 

Solar Electric Power: Photovoltaic panels by BP Solar, with a 25-year limited warranty, rated capacity 2.0 

KW AC. The electric output of each panel installation will be verified by SMUD. The Xantrex inverter 

system actually allows the electric meter to run backwards. See the SMUD press release for more details. 

Tankless Water Heater: Electronically controlled high-efficiency gas appliance by Noritz. Provides an 

endless supply of hot water at a flow of 6 gallons per minute. Has no pilot light and uses no gas when not in 

use. 

Appliances: GE kitchen appliances are extremely efficient. The dishwasher carries the ENERGY STAR 

label (ENERGY STAR does not rate ranges and microwaves). The range features the latest design highperformance 

gas oven. The built-in microwave and designer stainless steel finish on all appliances are both 

standard features. 

Radiant Heat Barrier: LP TechShield roof sheathing reduces summer heat gain and winter heat loss by 

reducing heat transfer by thermal radiation. 

High-Efficiency HVAC Components: Top quality York compressors (13 SEER, 11 EER) and furnaces 

(90% efficiency) meet or exceed the new state standards, and are much more efficient than units installed just 

a few years ago. 

Smart Vent System: This high-tech product makes whole-house fans obsolete. By using the HVAC system 

ductwork, Smart Vent circulates fresh cool filtered outside air throughout the house, without the need to open 

windows and let in dust. 

Zoned Heating and Cooling: Provides comfortable indoor temperatures in two-story homes, using Beutler’s 

patented ZTE system. 

Upgraded Ducts: Insulated and tightly sealed ducts maximize the efficiency of the HVAC system. Installed 

ducts are field-tested for performance through a sampling program conducted by a trained third-party 

inspection service. 

Lighting: All exterior and interior lighting fixtures feature the latest in energy-efficient fixtures, with 

brushed nickel finishes. Fluorescent fixtures include bulbs designed to produce natural lighting in the critical 

kitchen and bath areas. 

Two Stage Toilets: Sterling dual flush toilets provide improved performance and save water. According to 

the manufacturer, a typical family can save up to 6,000 gallons per year. 

High-Tech Piping: PEX water supply piping has been proven for decades, and is now available for use in all 

50 states. Wirsbo’s AquaPEX piping uses brass fittings and is extremely reliable, because it has far fewer 

joints and connections than traditional copper. PEX also eliminates “pipe hammering” noises. 

Ward Flex gas piping is a proven engineered product that is superior to traditional cast iron piping. 

23

Engineered Foundation: Ten inch thick concrete slab, reinforced with 5/8” steel reinforcing bars. Upgraded 

concrete mix includes Polyheed 997 water reducer to increase strength and reduce permeability. Concrete 

samples are laboratory tested for strength. 

Enhanced Exterior Moisture Control: Treasure Homes’ industry-leading exterior moisture control system 

includes a Tyvek vapor barrier membrane, the Total Wall foam lath system, Quickflash brand flashings of 

wall penetrations and upgraded caulking products and window flashings. 

Engineered Wood Products: Upgraded construction materials include the LP TechShield Radiant Heat 

Barrier roof sheathing, TJI Floor Joists, Socomi Lam barge rafters, LP SmartPanel roof overhangs, and 

AZEK PVC trim in high-impact areas. 

Super-efficient Windows: Dual pane windows with specially coated “Low E-Squared” glazing to reduce 

radiant heat gain. Vinyl frames feature reduced conductivity to minimize the gain or loss of heat. 

Gas Fireplace: Burns cleanly and efficiently, and without generating the high levels of airborne particulates 

produced by wood-burning fireplaces. 

Gas Dryer Connection: Homes are pre-plumbed for gas dryers, which are more efficient than electric. 

Depending on your usage, a gas dryer could save your family $60 per year. Refer to energyguide.com 

Low Voltage Wiring: Channel Vision structured wiring system and security alarm system pre-wiring are 

included, as well as television and telephone lines in all bedrooms. 

Insulation: All ceilings are R-38, and all stucco wall systems are a total of R-18. Even the Harmony front 

door is insulated, with an attractive and durable fiberglass exterior. 

Figure 10. ZEH features for Fallen Leaf 

Figure 11. Fallen Leaf sales center / model 

24

2.5. Case Study #5: Pardee Homes – Soleil (San Diego, California) 

Pardee Homes is a large builder that builds an average of 1000 homes a year in southern 

California and the Las Vegas area. Pardee’s executive management has exhibited a 

personal interest in building nothing but energy efficient homes. All Pardee Homes 

projects are built to meet or exceed ENERGY STAR home standards. 

Pardee Homes has also been building with renewable solar electric panels in the DOE 

ZEH program. To date, they have built approximately 60 ZEHs. The “Soleil” community 

with more than 20 ZEHs is Pardee’s largest solar project and is supported by the DOE 

program. Home range in size from 2353 ft 2 to 2730 ft 2 and are sold in the mid $800,000 

range. Although the builder offered solar in other projects, only one or two ZEHs were 

sold. 

The only rebate was from the California Energy Commission buydown of $2.60/watt for a 

PV system. The average net incremental cost including rebates for these homes was 

approximately $21,000. Although the rebate was not as large as for other projects in 

northern California, Pardee Homes still built ZEHs at Soleil. Besides being an innovative 

builder, Pardee Homes also participated in ZEH for the following reasons: 


particular 


• Incentives would decrease the incremental cost 

Figure 12 below shows the ZEH features of Soleil and Figure 13 shows marketing 

materials. 

25

Pardee Homes 

"Soleil" (AKA Bordeaux II) 

Floor Area = 

San Diego - CZ 7 

Energy Code Building Features 

Zero Energy Home (ZEH) w/ 2.4kW DC PV 

ENVELOPE: (Insulation R-Values) 

Roof (at flat) 30 

Roof (at furnace) 19 

Wall (2x4 Exterior) 13 

Wall (2x6 Exterior) 13 

Floor (above grg/cant) 13 

Attic Radiant Barrier No 

Low Air Infiltration Yes 

GLAZING: Vinyl frame windows with spectrally selective glass 

U-Factor 

Slider (horz)* 0.34 

Slider (vert)* 0.34 

Fixed* 0.32 

Patio* 0.36 

Glassblock 0.57 

French Doors* 0.55 

SHGC 

Slider (horz)* 0.31 

Slider (vert)* 0.31 

Fixed* 0.32 

Patio* 0.35 

Glassblock 0.67 

French Doors* 0.70 

HVAC SYSTEM: 

Furnace: AFUE 0.80 

A/C: SEER (if option is chosen) 10.0 SEER 

Duct Insulation / Location 4.2 

Duct Testing Yes 

ACCA Manual D Yes 

WATER HEATING: 

Water Heater Size Tankless 

Energy Factor 0.82 

Distribution Type Standard 

3rd Party Inspections and Testing (In ComfortWise Program) Yes 

Gas dryer stub Yes 

Fluorescent lighting (screw-in lamps) All Downlights 

GE Solar (BIPV) 2.4kW DC System 

Figure 12. ZEH features for Soleil 

26

Figure 13. Soleil plans 

Appendix C features more information about the case studies discussed in this report, as 

well as information on additional ZEH case studies. 

27

3.0 Discussion on Case Studies 

3.1. Advantages to the Builder 

Below are some of the reasons builders are building ZEHs. There are five major benefits to 

builders for building ZEHs communities, each of which is discussed in more depth below: 

• Federal and utility incentives/rebates 

• Marketing and media success 

• Collaborative partnerships 

• Competitive sales 

• Enhanced reputation and positive exposure 

3.1.1. Federal and utility incentives/rebates 

Federal, state, and utility incentives were available to the builders and homeowners. 

Rebates are essential for building ZEHs to offset the gross incremental cost, which ranges 

from $18,000 to $25,000, or roughly 3% to 7% of the cost of the homes. 

As seen in the case studies, the net incremental cost to the builder ranged from $8,000 to 

$15,000 with rebates and incentives. This range will impact less expensive homes more 

than high-end homes. For example, a $15,000 incremental cost will have a bigger burden 

on homes that are sold at $350,000 than on homes sold at the $850,000. However, builders 

are constantly trying to cut costs, and every single rebate will help decrease the 

incremental cost to the builders. 

3.1.2. Marketing and media success 

The ZEH case studies detailed in this report are all successful and nationally recognized 

due to the marketing support from the ZEH team. These homes also sold very well, 

presumably due to the ZEH program in conjunction with demand-side management 

programs offered by the utilities and the ENERGY STAR program. With support and 

marketing from all of these programs, the ZEH developments have drawn numerous 

media and newspaper coverage and have also appeared in numerous trade journals. 

3.1.3. Collaborative partnerships 

The ZEH builders increased their involvements with non-profit, business, and 

government organizations by building ZEHs. Collaborating organizations included 

utilities, building departments, the DOE BA and ZEH programs, National Renewable 

Energy Lab, the California Energy Commission, PV manufacturers, and other product 

representatives. These partners provided innovative building designs and energy 

efficiency design techniques. They also provided the best construction protocols and 

made sure the homes were built, tested, and inspected to the highest standards. 

3.1.4. Competitive sales 

ZEHs sold just as well as non-ZEHs in all of the ZEH projects. As seen with Premier 

Homes and Clarum Homes, their ZEHs sold out even before the projects were completed. 

A study by the RAND Corporation is underway to research the buying factors for 

homeowners in the Premier Gardens ZEH project and the Cresleigh Homes conventional 

28

project in Rancho Cordova (two side-by-side projects). Study results should be available 

in 2006. 

3.1.5. Enhanced reputation and positive exposure 

The media coverage provided the builders excellent local and national exposure and built 

up the builders’ reputations. The estimated value of the media coverage is in the 

hundreds of thousands of dollars and the coverage was perceived as a major benefit by 

the builders. 

3.2. Disadvantages to the builder 

Although ZEH builders experienced numerous benefits, some disadvantages surfaced 

and are discussed in this section. 

3.2.1. Cost 

The cost to build to ZEH standards was an issue for builders, even after rebates and 

incentives. The average net incremental cost of achieving ZEH was from $8,000 to $15,000 

and was economically challenging. In fact, all ZEH cases did not result in an economic 

advantage. 

The PV system was the most expensive component, at approximately $8,500 per one kW 

DC. Although the incremental cost of the energy efficiency measures (up to $4,000) 

seemed inexpensive compared to the cost of the PVs, they also were a significant cost to 

the builder when applied to numerous homes or to a 100% ZEH community. 

Typically, builders are trying to cut costs as much as possible, and the ZEH package was a 

considerable initial risk for builders, since they did not know whether the homes would 

sell at a price that would fully cover the additional costs. 

3.2.2. ZEH sold as an option were a liability 

As discovered in the case studies, it was better to pre-plot ZEHs or build 100% ZEH to 

save time and money. When homes were pre-plotted for ZEH or 100% of the homes were 

ZEHs, they sold just as well as non-ZEHs. However, when the ZEH was sold as an option, 

as found in previous ZEH projects, builders sold one, two, or none due to the following 

reasons: 

• Most homebuyers would not spend up to $30,000 (including mark ups from the 

builder) to have a ZEH option in a home. 

• The pressure is on sales agents to sell the benefits of ZEH. Most are not trained 

well enough to explain the concept of ZEH. Even given sales commissions, the 

ZEH option was hard to sell. 

Given the findings, it was a waste of time, effort, and money to the builders, engineers, 

and PV manufacturers to design the homes to ZEH standards when the ZEH option 

would not sell. 

29

3.2.3. Learning curves caused delays (builders, electricians, roofers, and cities) 

There was a learning curve for both the builder and the subcontractors. Builders’ sales 

staff needed to attend additional ZEH training classes to market their homes because they 

did not understand the entire ZEH concept. 

The PV systems required that the electrician and roofer work together and communicate 

extensively to avoid delays, a relationship that rarely occurs in typical home construction. 

The roofer had to lay the PV arrays on the roof and drill a hole through the roof to drop 

the PV connection wires into the attic. The electrician then had to connect these wires and 

route them to the inverter and the main electrical panel. These tasks were beyond their 

normal scope of work and necessitated an understanding of PV installation procedures. 

Ordering of the PV systems was also time-consuming, since builders had to schedule the 

arrival and installation of the PV panels. 

In addition, the city plan checkers and inspectors had trouble understanding ZEH 

features. For example, in Premier Gardens by Premier Homes and in Lakeside by 

Morrison Homes, buried ducts (when duct runs are buried in attic insulations to improve 

efficiency of the HVAC system) were one of the energy efficiency features. The city 

inspectors had issues with laying ducts on the roof trusses to be buried and wanted 

documentations from the uniform mechanical codes that ensured the procedure was 

acceptable. City plan checkers and inspector also questioned PV construction documents 

and installation procedures. These issues needed special attention and resolutions, and 

took two to three days to resolve, which delayed the construction schedule. 

City inspectors also delayed a ZEH project at the Clarum Homes Borrego Springs project. 

The project was on hold for four months because the inspectors did not know if the highmass 

walls and innovative HVAC systems incorporated in these homes met the structural 

or mechanical codes. 

3.2.4. Implications on collecting rebates (including federal tax credit) 

Since builders were already overwhelmed with the new technical details of ZEH, they did 

not want to spend the time and effort to collect all of the different rebates, especially with 

the federal rebates now available. Excessive paperwork had to be generated to acquire 

rebates and incentives, which took effort especially when documentation came from 

many sources. Builders typically had neither the time nor the expertise to pursue the 

various kinds of rebates. The energy consultants, HVAC contractors, and the utilities 

decided to take on the task of ensuring the paperwork for the rebates was correctly filed 

and that the rebates were delivered directly to builders. Most builders want the ZEH team 

to continue this role. With rebates available for the home buyer, the issue of collecting 

rebates may again fall to the ZEH team. 

3.3. Lessons learned 

The following section discusses the lessons learned from the ZEH projects. 

3.3.1. Great press and media coverage 

Media coverage in the form of press releases provided tremendous exposure for the 

projects at no cost to the builder. 

30

One of the lessons learned is that being innovative in building ZEH can result in extensive 

exposure and media attention, translating into free advertisement. Equating a dollar 

figure to the amount of press received by each ZEH project is difficult. As John Ralston 

mentioned in the Premier Gardens project, it was “certainly in the hundreds of thousands, 

maybe more” since he did “not know much about the cost of advertising on some of these 

national media like CBS and Good Morning America.” 

3.3.2. Lower electric bills and peak reduction 

While not a surprise, the electric bills confirm that ZEHs use less energy. Based on the 

electric bills from SMUD, the homes at Premier Gardens by Premier Homes use fewer 

kWh (or less energy) than typical Title 24 homes, and have even lower electricity bills 

when combining energy efficiency and PVs. 

More important, these homes also help reduce peak demand for summer afternoon loads 

because the afternoon PV generation overlaps with the utility’s peak load period. This 

directly benefits the utility by reducing peak demand and indirectly benefits the 

ratepayer, who ultimately pays for new utility infrastructure. 

It is important to note that lifestyles and behaviors of homeowners affect the energy bill of 

a home and that some ZEHs may use more energy than typical Title 24 homes. For 

example, the ZEH owner may decide to add a swimming pool, spa, or multiple 

appliances to the home. In the Morrison Homes Lakeside project, one of the ZEHs had 

consistently low energy bills for a few months and then the bills suddenly tripled. This 

was due to the addition of a spa, more televisions, and a swimming pool. Overall, 

however, when evaluating comparable lifestyles and behaviors, a ZEH will use less 

energy than a typical Title 24 home. ZEH owners are very pleased that they will be saving 

money due to the lower energy bills and have some insurance against energy price 

volatility. 

3.3.3. Financial implications to the builder 

Upgrading from Title 24 compliant standards to ZEH standards add a significant net 

incremental cost--approximately $8,000 to $15,000 per house. This was a financial 

challenge to the builders, who had no idea if they could recover the ZEH cost. Although 

building ZEHs may have been a financial burden at the start of all ZEH projects, the 

builders successfully recovered their costs at the end and gained a great reputation. In 

fact, a builder like Clarum Homes will continue to build to nothing less than ZEH 

standards, and as mentioned by John Ralston with Premier Homes, “it was worth it” to 

build to ZEH standards. 

3.3.4. PV Placement 

Builders do not typically install PVs on the front side of the homes because the panels are 

viewed as obtrusive and unattractive. However, orienting the PV arrays toward the east, 

south, or west is crucial to maximize electricity generation. Depending on street and 

house orientations, builders may need to install PVs on the front side of homes. 

Installing BIPV systems on the front side of the house to maximize electricity generation 

was something new to Premier Gardens. As stated by John Ralston of Premier Homes, the 

builder “did not know if this would have a negative affect on the homeowners.” After the 

31

homes were sold and occupied, Premier Homes found that “the homeowners did not care 

much because the BIPV system blended in aesthetically with the roof tile” 8. This was great 

news to Premier Homes because they can place PVs to optimize electricity generation, 

even on the front of the house, without changing roof plans or fearing that buyers may 

find it unattractive. 

3.3.5. Issues around installing monitoring equipment 

Several homes and PV systems discussed in this report were monitored to gather 

performance data, and some issues arose during the installation of the monitoring 

equipment. While the recorder is not difficult to install, it is important to have conduit for 

the wiring installed during the rough-in phase of construction. If installed during the 

rough-in phase, the wiring to the main power panel is hidden, reducing the visual impact 

and increasing the safety of the installation. Coordinating this task with the electrical 

contractor can be a challenge because the electrical contractor needs to meet contractual 

schedules and this ‘non-standard’ activity removes some flexibility. 

Installation of the current transformers (CTs) can also be a difficult problem. Issues 

primarily arose due to the use of the All-in-One panels that use metal buss bars in the 

circuit breaker section of the panel. It is impossible to mount CTs around these buss bars. 

The solution has been to obtain the utility’s permission to install the CTs in the ‘utility’ 

portion of the panel where the service wires are accessible. This installation requires 

utility technicians to actually perform the installation with supervision from an energy 

consultant. It also requires a cooperative utility that is willing to perform this extra work. 

Measuring natural gas usage using a second gas meter between the revenue meter and 

the house also created some challenges. There is usually insufficient space to place two 

meters near the gas entrance to the house. The best solution, to date, has been working 

with a utility company to allow the energy consultant to add a commercial magnetic 

pulser module to the existing gas meter. This eliminated the need for a second meter. It is 

important to note that the referenced gas meter solution was for a Nevada ZEH project. 

Again, a cooperative utility, in this case Southwestern Gas in Las Vegas, allowed the best 

solution to be implemented. 

8 Ralson, John. 2005. VP of Sale and Marketing, Premier Homes. ZEH Presentation. 

32

4.0 Recommendations for the Energy Commission’s ZENHome Program 

4.1. Cost and features 

The net incremental cost for ZEH features over a base Title 24 home in California ranged 

from $8,000 to $15,000, depending on the aggressiveness of the rebates from the utility 

service territories. For example, in investor-owned utility territories where the state 

incentive is only $2.60/watt for a PV buydown (compared to the $3.50/watt incentive 

from SMUD or the $4.00/watt incentive from Roseville Electric), it would be more 

expensive to build ZEHs. 

The net cost to achieve the PIER Utility-focused Market Model ZENHomes will depend 

on the rebates available at both the state and federal levels during project term (2006– 

2008), but will be similar to the incremental cost quoted from the ZEH case studies. The 

features required to achieve ZENHome goals are similar to ZEH features as well. 

It is important for the ZENHome project team (Architectural Energy Corporation, 

Southern California Edison, ConSol, Geltz Communications, ConsumerPowerline, and the 

PV manufacturer) to work to acquire all possible rebates and incentives to minimize the 

cost of building ZENHomes to the builder and homeowner. It also is important to identify 

and attempt to quantify benefits gained from media coverage, modifications in the 

entitlement processes, and mortgage advantages from significantly lower energy bills. 

4.2. Facilitate involvement of local government 

Local government participants need to be on-board early in the Utility-focused Market 

Model for ZENHomes project. Some of the energy efficiency features (e.g., DOW T-Mass 

walls, buried ducts, OASYS evaporative cooler, etc.) could require significant discussions 

with the local building department, resulting in project delays. The ZENHome team must 

work proactively with building departments to facilitate understanding of the features 

and minimize delays and, if possible, make these projects highly visible within the local 

government. Delays may be avoided and plan reviews may occur faster if the building 

department and city government are included as an integral part of the project. 

4.3. 1-kW requirement 

One of the goals for the PIER ZENHome Program is to achieve 1 kW peak demand in 

each home. This goal will be studied in the Utility-focused Market Model for ZENHome 

project. It is important to note that the ease with which the 1-kW goal can be met depends 

on the size of the home. The 1-kW goal will be harder to achieve for larger homes and in 

harsher climate zones. An in-depth discussion on the 1-kW issue and the effects of square 

footage and climate zones will be provided in future deliverables. 

33

5.0 Benefits to California 

Increasing the number of ZEHs in California would create major benefits for the state: 

• These homes have been shown to decrease energy use and peak demand, which in 

turn decreases the need for purchasing high-cost peak power and constructing 

new generation—potentially reducing energy costs for all ratepayers. 

• ZEHs are built to the very highest construction standards, and will therefore create 

a stock of quality, long-lasting homes in California. 

• Energy and peak reductions from each home will continue well into the future. 

• As the benefits of ZENHomes become more widely known and understood, these 

homes will create greater market demand for energy efficiency—thus proliferating 

the related energy and demand benefits. 

34

6.0 References 

Burton, Franklin. 1996. Water and Wastewater Industries: Characteristics and Energy 

Management Opportunities. Electric Power Research Institute Community Environmental 

Center Report CR-106941. 

35

7.0 Glossary 

AC air conditioning 

ACCA Air Conditioning Contractors of America 

AFUE annual fuel utilization efficiency 

BA Building America 

BIPV building-integrated photovoltaic 

BIRA Building Industry Research Alliance 

CARB California Air Resources Board 

CSI California Solar Initiative 

CT current transformer 

CPUC California Public Utilities Commission 

DOE Department of Energy 

ft 2 square feet 

EF energy factor 

ERP Emerging Renewables Program 

GE General Electric 

HVAC heating, ventilation, and air conditioning 

IEEC International Energy Efficiency Code 

kWh kilowatt-hour 

NREL National Renewable Energy Laboratory 

OVE Optimal value engineering 

PG&E Pacific Gas & Electric Company 

PIER Public Interest Energy Research 

PV photovoltaic 

SEER seasonal energy efficiency ratio 

SIP structural insulated panel 

SLA specific leakage area 

SMUD Sacramento Municipal Utility District 

TXV thermostatic expansion valve 

36

W watt 

ZEH zero energy home 

ZENHome zero energy new home 

37

Appendix A: Energy Analysis for Premier Gardens 

Premier Homes "Premier Gardens" Plan 2248 w/ Options (ZENH Peak Analysis) 

Rancho Cordova, CA - CZ 12 

PV Hourly Generation Non Cooling Energy use 

(Typical 20° roof pitch with PV facing West) 

day time Cooling enduse in kWh kWh 

14-Jul 15 1.276 (divided by 2) Refrigerator 0.074 annual use 650 kWh/8760 hours in the year 

14-Jul 16 1.192 Lighting 0.180 kitchen - 18w x 6 fixtures and bathroom - 18 w x 4 fixtures 

14-Jul 17 1.008 

Appliances & Plug 

Loads 0.205 annual use 1800 kWh/8760 hours in the year 

14-Jul 18 0.68 Total 0.460 

14-Jul 19 0.245 (divided by 2) 

Peak hour based on SMUD is 5.00 pm on July 14TH 

Micropas peak hour results 

day time Cooling enduse in kWh 

14-Jul 15 0 (divided by 2) 

14-Jul 16 0 

14-Jul 17 1.858 

14-Jul 18 1.624 

14-Jul 19 0 (divided by 2) 

Peak Hour kWh 

Cooling energy use 0.871 

Non Cooling energy use 0.460 

PV output 0.910 (2.4 kW DC PV) 

Net Energy Consumption 0.4 

Hourly House Energy for July 14th based on Micropas 

HEATFUEL HEATELEC COOLFUEL COOLELEC COOLELEC 

Hour (Btu) (Wh) (Btu) (Wh) (kWh) 

15 0 0 0 0 0 

16 0 0 0 0 0 

17 0 0 0 1858 1.858 

18 0 0 0 1624 1.624 

19 0 0 0 0 0 

Total 0 0 0 3482 3.482 

Hourly PV Generation per GE Solar (2.4 kW DC) 

Table 1: Plan 2248 Peak Analysis 

A-1 

Hour kWh 

15 1.276 

16 1.192 

17 1.008 

18 0.68 

19 0.245

Appendix A: Energy Analysis for Premier Gardens 

Comparison of Total Energy Use 

Plan 2248 and Options 

Title 24 Code House 

ZEH: Tankless WH, 

Fluorescent lighting, 2.4kW 

DC PV, Inspections and 

Diagnostics 

Energy Use Dollars Energy Use Dollars 

Therms kWh $ Therms kWh $ 

Energy Code Related 

Space Heating 387 $290.50 267 $200.13 

Space Cooling 2158 $179.58 891 $ 74.17 

Water Heating 239 $179.39 164 $122.74 

Other Uses 

cooking 44 $ 33.00 44 $ 33.00 

microwave 209 $ 17.39 

209 $ 17.39 

dishwasher 361 $ 30.04 

361 $ 30.04 

cloths dryer 700 $ 58.25 35 $ 26.25 

refrigerator 1100 $ 91.53 

1100 $ 91.53 

Miscellaneous 1800 $149.78 1088 $ 90.55 

reduce kWh by solar contribution n/a -3,420 $284.58 

Total use 671 6328 $1,029.46 509 230 $401.23 

100% 96.37% 61% 

price of gas/therm $ 1.00 

price of electricity/kWh $ 0.11 

Table 2 : Comparison of Total Energy Use 

1 

1067 $ 85.79 /mo $ 33.44 /mo

Appendix B – ENERGY STAR, SMUD Advantage, and ComfortWise 

ENERGY STAR 

ENERGY STAR qualified homes are independently verified to be at least 30% more energyefficient 

than homes built to the 1993 national Model Energy Code or 15% more efficient than 

state energy code, whichever is more rigorous. These savings are based on heating, cooling, and 

hot water energy use and are typically achieved through a combination of: building envelope 

upgrades, high performance windows, controlled air infiltration, upgraded heating and air 

conditioning systems, tight duct systems and upgraded water-heating equipment. 

These features contribute to improved home quality and homeowner comfort, and to lower 

energy demand and reduced air pollution. ENERGY STAR also encourages the use of energyefficient 

lighting and appliances, as well as features designed to improve indoor air quality. 

Website: http://www.energystar.gov/ 

SMUD Advantage 

SMUD Advantage Homes are built with a package of energy-efficient features. SMUD offers 

two levels of Advantage Homes – Tier III and Gold. More information is available at the below 

url. 

Website: http://www.smud.org/residential/saving/advantage/index.html 

ComfortWise 

ComfortWise is a proprietary program by ConSol. ComfortWise homes are at least 30% more 

energy-efficient than required by the national Model Energy Code and 15% more energyefficient 

than required by California Residential Energy Efficiency Standards (Title 24). 

ComfortWise homes qualify for the Department of Energy and the Environmental Protection 

Agency’s ENERGY STAR® Homes program, but ComfortWise homes exceed even ENERGY 

STAR standards. The ComfortWise program requires specific energy features. 

Website: http://www.comfortwise.com/index.shtml 

1

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