Residential Energy Codes and Best Practices

The six-state Southwest region of the United States (Arizona, Colorado, Nevada, New Mexico, Utah and Wyoming) is a fast-growing region that experienced a large growth in new housing starts up to the housing recession and subsequent large drop in housing starts during the housing recession. Since the turn in the recession the southwest has lead the recovery in new housing starts and it is anticipated the region will continue to lead the nation with housing starts.

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 beyond-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 the newest energy code requirements for new single-family homes in the Southwest region would result in the following energy and cost savings over a twelve year period through  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. 

Steps for Adopting a Residential Beyond-Code Program

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

  1. Establish the performance level for above-code programs. As many states and communities have adopted the 2012 IECC the “stretch” in energy efficiency could be anywhere from 10% to 30% energy savings.
  2. 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.
  3. 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.
  4. 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.
  5. Adopt and enforce the code, and provide training and technical assistance to builders and building trades on complying with the new code requirements. 
  6. 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).

Advanced Energy Code Adoption

A few communities in the Southwest have adopted "advanced 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 consume 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 the city of 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 Green Building Initiatives page.

SWEEP Programs and Information Resources

SWEEP has developed a Guide to Developing "Beyond Code" Programs to help state and local governments design and implement successful efficiency programs for new commercial and residential buildings in the Southwest. The guide provides detailed descriptions and analysis of previously implemented programs, including lessons learned and best practices."

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 studiespublications, and policies and legislation sections of the SWEEP web site.

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.