Construction Trends for Energy Efficient Homes in California

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Construction Trends for Energy Efficient Homes in
California

• Laura Stevens
• McNair Scholars Program
• Mentor Ted Bradshaw, Ph.D.
• Department of Community and Regional Development
• University of California, Davis

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Introduction
Why do we need energy efficient homes?
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Introduction

• Eliminate our dependence on fossil-fuels
• Lower emitted greenhouse gases (global warming)
• Lower dependence on imported energy
• Eliminate the risks of power shortages
• Failed transmission lines
• Deliberate manipulation of the energy market.
• Improved housing quality and lower costs
• AffordabilityLower lifetime costs
• Comfort

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Hypothesis
Super-insulation provides the greatest energy
efficiency in commercially-built residential
communities as measured by the Home Energy Rating
System (HERS)
Bigelow Home Duplexes (joined only at the
garage).
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Background
Research premised on construction standards set
by Perry Bigelow in Illinois Bigelow Homes -
Commercially-built affordable, energy-efficient
housing (early 1990s)
Bigelow duplexes (joined only at the garage).
Living areas range from 86 to 350 m2 (930 to 3800
ft2),including basements.
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Background
Perry Bigelow Homes in Aurora, Illinois has been
a leading proponent of energy-efficient,
affordable houses.
A three-year heating guarantee. "We guarantee
that heating costs will not exceed 400 a year. .
. . We will reimburse the owner the difference if
the cost of heating is higher," said Mike
Venetis, VP Marketing for Bigelow.
(COSTA MESA, Calif. 9/8/2003) Bigelow Homes to
Help Close Gaps on Homelessness
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Background Previous Studies
Studies on Bigelow Homes
January 1995 Issue 10
Typical Conventionally-built homes in area exceed
1000 therms (average gas price during the study
period was about 40 per therm)
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Background Public Policy
1993 Model Energy Code (MEC) 1995 Energy Star
Homes (exceeds MEC by 30) 2000 (Title 24) AB
970 Urgency Legislation 2001 (Title 24) SB 5X
Urgency Legislation 2005 (Title 24) Effective
Oct.1 New Standards 2010 Zero Energy Homes
(exceeds MEC by 90)
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Background Public Policy
EPA Energy Star Homes Campaign Benchmark to
exceed the 1993 Model Energy Code standard by a
minimum of 30. Min. Home Energy Rating System
(HERS) score of 86
Look for this label when buying your next home.
Look for this label when buying your appliances
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Background Research and Development
By 2010 U.S. Department of Energy (Building
America) Cost-effective systems for homes that
produce as much energy as they use a zero energy
home. (ZEH)
Four Teams Consol, Stockton, California Davis
Energy Group, Davis, California NAHB Research
Center, Upper Marlboro, Maryland Steven Winter
Associates, Norwalk, Connecticut
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Background Currently.1,532,000 Single Family
Homes built in 2004(To date -- 302,000 Energy
Star Homes built)
304 (12)
119 (6)
700 (38)
409 (44)
1. Attached and Detached Homes 2.Percentage of
ESH
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Methods/Materials
Qualitative surveys were sent out to contractors
in California who met or exceeded Title 24,
Energy Star and ZEH. Ratings based on EPA
Energy Star homes campaign Benchmark to exceed
the 1993 Model Energy Code standard by a minimum
of 30. (Minimum Home Energy Rating System
(HERS) score of 86)
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Methods/Materials Primary and Secondary Data
Rated for Residential Housing

• Data on construction techniques used in the
  energy efficient homes and Bigelow Homes were
  collected
• Government and Developers website
• Two case studies (Energy Star and ZEH)
• Interviews via phone, email and face-to-face

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Results
177 Energy Star Contractors in California (top
15 Listed) and 9 ZEH Contractors Nationwide
ZEH BUILDERS Centex Homes Clarum Homes Morrison
Homes Pardee Homes Ponderosa Homes Premier
Homes Schingler Development Shea Homes Standard
Pacific Homes William Lyon Companies
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Results Ca. has additional construction rating
standardsClimate and Energy Budget Zones (Title
24)

• Climate Zone (CV)
• CZ 1 Arcata CZ 2 Santa Rosa CZ 3 Oakland
  CZ 4 Sunnyvale CZ 5 Santa Maria CZ 6 Los
  AngelesCZ 7 San DiegoCZ 8 El Toro CZ 9
  PasadenaCZ10 RiversideCZ11 Red BluffCZ12
  SacramentoCZ13 FresnoCZ14 China LakeCZ15 El
  CentroCZ16 Mount Shasta

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ResultsClimate Zones and Energy Budget Zones
Aurora, Illinois (Kern County)
Zone 14 COLD Based on a ratio of days above and
below (65F basis)
Sacramento, California (Sacramento County)
Zone 6 HOT-DRY less than 20 in. rain above 45F
1,500 Energy Star Homes (4 in Midwest)
49,000 Energy Star Homes (43 in West)
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Results Then and Now
1980s-1990s Bigelow 1993 MEC Today Energy
Star HERS score 89.7 HERS score
80 HERS score 86
49 0 30
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Results Tightness, Ventilation and scaled-down
HVAC
Did You Know?The typical household spends
1,500 a year on energy bills. With ENERGY STAR,
you can save up to 30 or more than 450 per
year. EPA

• Three primary construction techniques
• Tested Tightness
• Simple Ventilation
• Scaled-down HVAC/Dist.

Energy sources are electricity, natural gas, fuel
oil, kerosene, and liquefied petroleum gas.
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Case Study D.R. Horton Inc.Elk Grove, Ca
(Energy Star Home)
Largest Model Home (Nautilus) 2663 Sq.Ft. 5
bedroom, 3 bath, 2 laundry locations, 3 bay
Garage As of July 2005, Sale Price 494,000
Click on picture to start short video
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Results Migrating to ZEH
Building America Research Teams are introducing
ZEH concepts into the single-family, new home
construction Industry.
Photovoltaics (PV)
Uses 90 less energy than conventional homes 
DOE press release 2004
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Case Study Premier Homes (ZEH Homes)Elk Grove,
Ca
Premier ProEnergy at Premier Gardens At Premier
Gardens, youll find something truly unique in
todays new home market. This is the first
community of its kind in the Sacramento regiona
community that offers a Zero Energy Home as a
standard feature. But what does that mean to you,
the homebuyer? How about a savings of up to 60
on your monthly utility bill? Now thats the way
a home should be. Here are some of the energy
saving features you will find in your Premier
Gardens home.

As quoted by the Sales Agent, Location,
Location, Location New Premier homes being
built in Live Oak, Ca. are selling for 350,000
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Conclusion Superinsulation
Without Superinsulated houses, reducing the
demands for heating/cooling may not be possible.
1993
2005
2010
Using alternative energy sources does not make a
home more energy efficient -- just cheaper to
run. Its in the homes tight construction that
true efficiency is realized.
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Discussion
Studies have shown HERS (Home Energy Rating
System) does not account for variations in
occupancy and socio-economic habitation.
(Accuracy of Home Energy Rating Systems Lawrence
Berkeley National Laboratory, 1997) Next
StepUnderstand how super energy efficient
housing can be introduced into the affordable
housing market.
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Acknowledgements

• Professor Ted Bradshaw
• D.R. Horton Homes (Elk Grove, Ca)
• Premier Homes (Elk Grove, Ca)
• McNair Scholar Program

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Construction Trends for Energy Efficient Homes in
California

• Laura Stevens
• McNair Scholars Program
• Mentor Ted Bradshaw, Ph.D.
• Department of Community and Regional Development
• University of California, Davis