Southwest Energy Efficiency Project

Residential Energy Codes and Best Practices

Benefits of Adopting
Above-Code Programs for New Homes

Homebuyers benefit by having lower energy bills and a home that is more energy efficient, comfortable, durable, and environmentally friendly.
Homebuilders benefit by offering a higher quality, product, with fewer warranty and ‘callback’ issues.
States, cities and utilities benefit by having desirable communities that reduce demand for new energy supplies and infrastructure.

The six-state Southwest region of the United States (Arizona, Colorado, Nevada, New Mexico, Utah and Wyoming) is a fast-growing region that is experiencing a boom in population and new housing construction. Nearly 2 million homes are projected to be built in the Southwest between 2008 and 2020, equivalent to about 150,000 new homes per year.

Adopting and enforcing building energy codes that go well beyond current requirements is one of the most cost-effective ways to reduce energy use in new homes. This section describes the savings potential and cost effectiveness of adopting residential energy building codes, steps for adopting a program with local examples, and information on SWEEP’s programs, publications and activities in support of residential above-code programs.

Savings Potential and Cost Effectiveness

The energy, economic and environmental benefits of improving the efficiency of new homes in the Southwest region are significant. SWEEP estimates that adopting above-code requirements for new single-family homes in the Southwest region would result in the following energy and cost savings between 2008 and 2020:

Over 2.7 million GWh of grid electricity savings– enough electricity to meet the annual electricity consumption of approximately 250,000 typical households.
A 200 MW reduction in peak electricity demand, with average hourly summertime peak loads per home reduced between 50 and 67%.
Reduction in residential natural gas consumption of 228 million therms (up to 50% reduction in natural gas use per household).
Southwest households would save a total of $500 million in reduced electricity and natural gas bills (average savings of $600 per household, annually).
Emissions of greenhouse gases from power plants would be reduced by 2.4 million tons of CO2 between 2008 and 2020.

Steps for Adopting a Residential Above-Code Program:

Developing and adopting an above-code requirement for new homes typically involves the following steps. See the local examples below for additional information about above-code programs, including guidelines developed by individual communities.

Establish the performance level for above-code programs. Most communities pursue programs that achieve 30% energy savings, although a few have also pursued programs targeting higher levels, including net-zero energy goals for new homes.
Identify what types of homes will be affected. Most programs include new single-family homes, and major renovations or additions to existing homes. Separate standards for multi-family housing (low-rise and high-rise) and affordable/low-income housing may also be considered.
Obtain input from affected stakeholders, including homebuilders, contractors and trades, green building organizations, and residents. Municipal building officials, planning staff, and building code enforcement officials should also be consulted.
Prepare legislation requiring an advanced code. Typically, city or county staff prepares a draft ordinance or legislation establishing the advanced code requirements, which are then implemented by the planning and building departments as a new energy code, or amendments to existing codes, such as the IECC.
Adopt and enforce the code, and provide training and technical assistance to builders on complying with the new code requirements.
Track and evaluate progress toward implementing the code annually, and review and update the energy savings goals and code requirements periodically (typically every 3 years).

Progressive Codes

A few communities in the Southwest have adopted ‘progressive energy codes’ that increase in stringency as home size increases, or require payment of impact fees for large homes or for energy-intensive exterior features (e.g., heated roofs and driveways). Incorporating home size into building codes and land use policies is a new trend that is designed to counter the trend toward larger homes, which consumer more energy and resources than smaller homes (the average house built today is about 30% larger than a home built in 1970). Communities that have adopted or are considering ordinances addressing house size include Austin, Texas, Boulder County and the City of Aspen, Colorado, and Marin and Santa Cruz Counties, California.

Program Examples and Best Practices

The following communities have adopted residential building codes or green building guidelines that go well beyond minimum energy code requirements:

For more information about these and other residential energy code programs, see the G reen Building Programs page.

SWEEP Programs and Information Resources

SWEEP has completed several reports and studies that analyze the savings potential from adopting more stringent residential building energy codes, and provide recommendations to state and local officials and other policymakers for adopting and enforcing above-code programs. A list of key reports is provided below; for more information, see the case studies, publications, and policies and legislation sections of the SWEEP web site.

SWEEP is also providing technical assistance to help local governments throughout the Southwest develop and implement above-code residential building codes, and is preparing a guide to above-code programs for state and local governments.

The following SWEEP reports and studies provide analysis of the savings potential from adopting energy efficient residential building code requirements, along with policy recommendations for developing and adopting building codes at the state and local levels.

High Performance Homes in the Southwest, November 2007
Building Energy Codes in Arizona: Best Practices, September 2007
Increasing Energy Efficiency in New Buildings in the Southwest: Energy Codes and Best Practices

© 2002-2008 Southwest Energy Efficiency Project
2260 Baseline Rd. Suite 212, Boulder, CO 80302
(303) 447-0078 fax: (303) 786-8054 info@swenergy.org

Last Updated: 04/07/2008