energy codes
Similar to building and rehab codes, which lay out design and construction specifications to achieve minimum levels of building safety, energy codes (which are a subset of building codes) detail standardized measures intended to achieve minimum levels of energy efficiency in new homes and existing buildings undergoing substantial rehabilitation. Adoption of an energy code helps to ensure that all new construction and substantial rehab projects will meet or exceed these minimum standards, resulting in energy savings that extend over the life of the building.

Energy codes apply to a subset of activities addressed by traditional building codes, and cover areas most closely related to energy consumption, including:
  • "Wall and ceiling insulation,
  • Window and door specifications,
  • Heating, Ventilation, and Air-Conditioning (HVAC) equipment efficiency, [and]
  • Lighting fixtures and controls." [1]
Most states rely on national model codes to provide a foundation for a state-specific energy code. Learn more about model codes and their benefits.
The energy and cost savings that result from adoption of energy codes can be significant.
energy codes, some of the nation's strictest, apply to new construction, additions to existing buildings, and alterations that change the building envelope or space-conditioning, water heating, or lighting systems. [2] Through compliance with energy-efficiency regulations, the state has realized savings of more than $56 billion in electricity and natural gas costs since 1978. According to the California Energy Commission, projected savings are expected to grow by an additional $23 billion by 2013. [3]

Similarly, a recently-published study reveals the effectiveness of Florida's statewide Energy Code over the more than thirty years and 15 updates that it has been in place. Florida's code applies to new construction as well as additions to existing buildings and renovations that affect the building envelope or HVAC, lighting or water systems and exceed a specified cost threshold. (If costs over a one-year period equal or exceed a cumulative total of 30 percent of the assessed value of the structure prior to the improvement or renovation or prior to when damage occurred, if renovation is in response to damage, then the project must comply with the Energy Code.)

Authors of the study report that with adoption of the 2009 version of the Energy Code, new homes built in Florida should be about 17 percent more efficient than homes built to similar model energy code published just three years before.

According to the Department of Energy's Database of State Incentives for Renewable & Efficiency (DSIRE), all states at least make reference to an energy code in some way, although the applicable sectors and stringency of enforcement vary widely. For example, South Dakota has developed a voluntary energy code for new residential construction. However, builders and sellers of all new single-family and small multifamily (4 or less units) homes must provide information on the building's energy efficiency to the buyer. In contrast, residential and commercial builders in Vermont must comply with mandatory statewide codes, which undergo updates on a 3-year cycle. Several local jurisdictions, including Chicago, IL and Austin, TX, have also adopted their own energy codes. Local codes typically include more rigorous requirements than those at the state level.

Prescriptive versus Performance-Based Codes
In most cases, energy codes describe a series of measures that must be taken in order to achieve compliance with the code. For example, the code may specify certain types of acceptable insulation, or require that all furnaces installed demonstrate a minimum level of performance efficiency. This "prescriptive" approach assumes that buildings that conform to the code's requirements will achieve a desired level of energy efficiency.

In contrast, performance-based energy codes use total energy consumption as a starting point, and give builders and developers more flexibility to adopt the energy-conserving measures needed to achieve this target. Under a performance-based code a builder may choose to install a relatively low level of insulation but a highly-efficient furnace, as long as these trade-offs result in the desired level of energy efficiency for the overall structure. [4]
Solutions in Action
In January 2010, a California state commission unanimously approved a new building code, CALGreen, which has been described as the most stringent state code in the nation -- both in terms of its energy-efficiency requirements as well as requirements related to other environmental goals. The mandatory code, which applies to all residential, commercial, hospital, and school buildings, became effective in January 2011 and includes the following requirements for developers of new construction in California:
  • Reduce indoor water consumption by 20 percent, with voluntary standards for additional reductions; [5]
  • Divert 50 percent of construction waste from landfills, with voluntary standards for achieving a reduction of 65 to 70 percent for new homes;
  • Install low pollutant-emitting materials, including paints, carpeting, and flooring [6]
The California Building Standards Commission, Department of Housing and Community Development, Division of the State Architect, and Office of Statewide Health Planning and Development developed CALGreen in consultation with builders and architects, environmentalists, local officials, and other stakeholders.

Authors of the code drew from existing green building practices and rating systems to provide a minimum set of enforceable standards related to building safety and sustainability; however, municipalities that choose to do so may adopt more rigorous local energy codes through a local amendment process described in California's Building Standards Code. [7]

Similar to processes used to enforce other building and fire safety codes, before a certificate of occupancy has been issued, all projects will be subject to field inspection and verification by state and local building inspectors.

Recommendations for Adoption of an Energy Code
Adapted from Building Codes Assistance Project's Best Practices for State Building Energy Code Policy [PDF]

- Adopt a mandatory, rather than voluntary, energy code for residential and other buildings

- Put into place an automatic revision process to ensure that codes undergo regular review and stay up-to-date with newly-released model energy codes that reflect innovations or clarifications in the building and energy-efficiency industries

- Increase code uniformity across building sectors (residential, commercial, etc.) to make development easier and more cost-effective, and facilitate enforcement of code requirements

- Mandate code enforcement and provide support for local building inspectors through trainings, education materials, and other resources

- Enhance existing energy codes with voluntary "above-code" energy rating systems and tools that encourage innovation and provide incentives for adoption of energy-saving and other green building measures that go beyond those mandated in the code

Look at the Department of Energy's Status of State Energy Codes map to see which energy codes states have adopted.

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Energy codes, similar to traditional building codes, establish minimum requirements and guidelines for the performance of new construction and existing homes undergoing substantial renovation

Other pages in this section:

David and Joyce Dinkins Gardens
Energy rating systems and green building rating tools complement energy codes but encompass additional sustainability measures that may result in greater energy savings

Matthei Place
Point-of-sale efficiency upgrades
and audit requirements provide a mechanism for reducing energy use in existing homes when they are put up for sale

Broadway Crossing
Energy saving and emissions reduction laws
create incentives for utility companies to implement energy-saving measures, including home retrofits

Harold Washington Unity Coop
Other incentive-based programs
, including density bonuses and rebates on the purchase and installation of energy-efficient products, reward developers and residents that take steps to reduce energy consumption

[1] Energy Codes 101. Web Site. Washington, DC: Building Codes Assistance Project - Online Code Environment and Advocacy Network.
[2] 2008 Residential Compliance Manual, Chapter 1 - Introduction. [PDF] 2009. Sacramento, CA: California Energy Commission.
[3] California's Energy Efficiency Standards for Residential and Nonresidential Buildings. Web Site. 2010. Sacramento, CA: California Energy Commission.
[4] Energy Codes 101. Web Site. Washington, DC: Building Codes Assistance Project - Online Code Environment and Advocacy Network.
[5] This requirement helps to achieve goals related to both water conservation and energy consumption. As noted in a 2005 report from the California Energy Commission, energy use related to the collection, treatment, delivery, and disposal of water accounts for 19 percent of the state's energy usage.
[6] 2013 CALGreen Residential Mandatory Measures. [PDF] 2013. Sacramento, CA: Department of Housing and Community Development.
[7] California's Next-Generation Upgrade to Title 24. Washington, DC: US Green Building Council.