Adopt Model Residential Building Energy Codes and Performance Standards

The International Energy Conservation Code (IECC) is developed and published by the International Code Council (ICC) and revised every three years through the ICC’s governmental consensus process. This code was designated as the residential model energy code by the Energy Policy Act of 1992.  States and local jurisdictions can choose to adopt and enforce the current code, or can opt for a higher, more stringent code to increase energy savings.

The adoption of model energy codes presents a significant opportunity to save energy in residential buildings. Because energy codes are adopted at the state and local level, local governments may have the ability to increase the minimum performance standards for homes and multifamily buildings through the adoption of stretch codes or high performance standards for new construction or major renovations, including zero energy standards. In some states, local jurisdictions may be restricted from exceeding the state adopted code. Find out the status of energy code adoption in your state. Local governments can also establish minimum energy efficiency performance standards for rental housing units to address the split incentive issue, where landlords are not incentivized to invest in energy efficiency in cases where tenants pay for utility bills. (For strategies targeted at affordable housing, see Strategy 6. Upgrade the Energy Efficiency of Affordable Housing in Your Community). 

A typical process for adoption of a model energy code by a state or local government.   

Once a code is adopted, code enforcement and compliance are critical. An energy code that is not complied with by designers or enforced by code officials is simply a document.  It is the compliance and enforcement that ensures the actual energy savings potential of energy codes. 

Jurisdictions that adopt a residential energy code need to prepare and support code officials to enforce the code. Many states and jurisdictions start the education process several months prior to an energy code change, oftentimes before adoption itself. Because of their close proximity, local agencies can have more regular interaction with designers and builders/contractors throughout the design and build process which can make code compliance verification easier. That said, some local governments lack sufficient resources to support enforcement and may turn to a state agency, utility, or other entity for enforcement support. Additionally, some states allow local jurisdictions to petition to conduct enforcement activities that usually are the responsibility of the state. << Back to Main Page


REScheck  for Residential Code Compliance: The REScheck product group makes it fast and easy for builders, designers, and contractors to determine whether new homes, additions, and alterations meet the requirements of the IECC or a number of state energy codes. REScheck also simplifies compliance determinations for building officials, plan checkers, and inspectors by allowing them to quickly determine if a low-rise residence meets the code.

List of Approved Software for Calculating the Energy Efficient Home Tax Credit: This website contains the DOE-Approved Software List which lists software that may be used to verify compliance with the energy efficiency requirements for the tax credit under section 45L of the Internal Revenue Code (§ 45L).

Residential Energy Services Network’s (RESNET’s) Home Energy Rating System ® (HERS) Index: The HERS Index is a measurement of a home’s energy efficiency as compared to code. To calculate a home’s HERS Index Score, a certified RESNET Home Energy Rater will do a home energy rating and compare the data against a 'reference home' – a design modeled home of the same size and shape as the actual home but built to IECC 2006 code.


DOE’s Building Energy Codes Program Website: This site has a great deal of information on both residential and commercial building energy code development, adoption, and compliance, as well as a resource center that provides a comprehensive collection of information, resources, and technical assistance designed to answer questions and address issues related to energy codes.

Going Beyond Code: A Guide to Creating Effective Green Building Programs for Energy Efficient and Sustainable Communities: This DOE guide was designed to help state and local governments design and implement successful “beyond code” programs for new commercial and residential buildings.

DOE Zero Energy Ready Home Program Participation Guidelines

DOE Zero Energy Ready Home Resources

The Economics of Zero-Energy Homes: This 2019 Rocky Mountain Institute (RMI) report demonstrates that the cost increase to build a zero-energy or zero-energy ready home is modest and highlights methods builders and policymakers can use to drive increased market penetration.

Better Rentals, Better City: Smart Policies to Improve Your City’s Rental Housing Energy Performance: This 2018 RMI report informs city leaders on mechanisms that can boost energy performance improvements in rental housing that benefit tenants, landlords, community leaders, and the environment.

U.S. Conference of Mayors Resolution Supporting Model Building Energy Codes: In June 2018, the U.S. Conference of Mayors unanimously adopted a resolution to urge mayors to adopt the International Energy Conservation Code (IECC) as a strategy toward net zero building construction by 2050.

Energy Efficient Codes Coalition Statement on Mayors’ Resolution on IECC Support: This press release from Alliance to Save Energy and Energy Efficient Codes Coalition highlights the U.S. Conference of Mayors IECC resolution.

  • Boulder, CO:
    Boulder’s SmartRegs adopted by City Council in 2010, requires all licensed rental housing to meet a basic energy efficiency standard.  Property owners can comply with SmartRegs energy efficiency requirements by following a prescriptive or performance path. Added in 2019, a new rental housing license requires proof of SmartRegs compliance at time of application submittal. All non-compliant SmartRegs rental properties' licenses will be expired and the units are no longer eligible to rent. As of March 2018, Boulder’s policy for minimum efficiency standards for rentals resulted in efficiency upgrades in 15 percent of the city’s total housing stock. Boulder also adopted a Net-Zero Energy Code in 2017, requiring new and remodeled residential and commercial buildings to meet net-zero emissions by 2031.
  • Massachusetts Municipalities:
    In 2009, Massachusetts became the first state to adopt a “stretch code”. The state’s Stretch Code focuses on energy performance rather than prescriptive requirements to result in cost-effective construction that is more energy efficient than that built to the “base” energy code. In parallel with the base code update to IECC 2015, the Stretch Code is also being updated, and is referred to as the 2015 Stretch code update. Municipalities may voluntarily adopt the Stretch Code instead of the base building energy code, but the stretch code is mandatory for designation as a Green Community under the Green Communities Act passed by the Legislature and signed into law in 2008. As of June 2019, more than 270 municipalities have adopted the Stretch Code and building code officials have received free code training.
  • Phoenix, AZ: 
    In a home-rule state with no statewide code, the city of Phoenix adopted the 2018 International Residential Code (IRC) which includes the residential energy provisions of the 2018 IECC.  While there is no statewide code in Arizona, approximately 65% of all new construction activity in the state occurs in jurisdictions under the 2012 IECC.
  • San Antonio, TX: 
    The state of Texas has the 2015 IECC as its statewide code.  San Antonio is the first city in Texas to adopt the 2018 I-Codes including the IECC with amendments (adopted on June 21, 2018 and effective October 1, 2018). 
  • Santa Monica, CA: In May 2017, Santa Monica became the first city to require all new single-family construction to be zero-net energy (ZNE). The ZNE ordinance is one strategy to help the city meet its goal to be carbon neutral by 2050. The ordinance applies to single family homes, including townhomes and low-rise multifamily residential projects less than or equal to three stories. City staff collaborated with the utility (Southern California Edison) and their consultant to analyze the cost-effectiveness of locally adopted standards that meet the CALGreen ZNE requirements. The ordinance’s timing takes advantage of state momentum towards ZNE and market trends in the solar industry. The Santa Monica Residential Zero Net Energy Guide for New Construction focuses on the general elements of ZNE homes and provides links to the specific details and requirements of Title 24 (California’s energy code) and Home Energy Rating System (HERS) verification.
  • St. Louis, MO:
    In a state with no statewide code, the City of St. Louis adopted the 2018 International Energy Conservation Code (IECC), the latest IECC code available. The code will ensure that all new residential and commercial buildings in the city meet a minimum threshold for energy efficiency, addressing heating and ventilation, lighting, water heating, and power usage for appliances and building systems. The lower energy costs expected from newly constructed residential buildings will particularly benefit St. Louis’ low-income residents, who according to the 2016 ACEEE study on energy burden in cities, spend more on energy bills than households in most other parts of Missouri. These impacts are particularly pronounced for African-American households and for renters, including in the large multifamily buildings that are being addressed through the city’s existing-building efforts. More information is available here.

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