There are two primary energy codes adopted by states in the Northeast: the International Energy Conservation Code (IECC) and the ASHRAE 90.1 Standards. The IECC contains code provisions for both residential and commercial homes and buildings, while the ASHRAE 90.1 covers commercial buildings four stories and higher. While states often adopt the IECC in its entirety for both residential and commercial homes and buildings, some states adopt the IECC residential code and the ASHRAE 90.1 commercial code.

Both of these codes are updated on three-year cycles; the latest versions are the 2018 IECC and ASHRAE 90.1-2019. Each new version comes with increases in energy efficiency along with more guidance and compliance pathways to help builders meet the code. States also adopt other codes, such as the International Green Conservation Code (IgCC), to further enhance energy savings in addition to regulating site, materials, and indoor air quality.  

International Energy Conservation Codes (IECC)

The International Energy Conservation Codes (IECC) is the predominant energy code adopted by states in the Northeast and Mid-Atlantic. Developed by the International Codes Council (ICC), the IECC has provisions for both residential and commercial homes and buildings. Updates every three years go through an ICC vetting process from initial proposal, review, and voting by industry experts and code officials before being approved and published for adoption. Collaboration between various energy-related industry groups during updates ensures that new codes are more comprehensive, incorporate flexibility for industry workers, advance energy efficiency, and improve overall home and building performance, comfort, and safety.

The newest version is the 2021 IECC, which was published in January 2021. The 2021 IECC exhibits a national average of 9.38 percent energy savings compared to the 2018 IECC, an initial DOE determination finds, and includes zero energy home and building appendices for both residential and commercial buildings. Click the button below to learn more about the new 2021 IECC.

ASHRAE 90.1 Standards

States often adopt the ASHRAE 90.1 standard to further regulate the energy efficiency of their commercial building stock. The latest version is the ASHAE 90.1 2019. 

ASHRAE was founded in 1894 to advance human well-being via the built environment. The American Society of Heating and Air Conditioning Engineers (ASHAE) merged with the American Society of Refrigerating Engineers in 1959 to become ASHRAE. ASHRAE promulgates model standards based on research and building science to improve the energy efficiency, indoor air quality, refrigeration, and sustainability of the building stock. They publish several standards, including the 90.1 commercial energy efficiency standard, 62.1 and 62.2 mechanical standards, and 189.1 green building standard, to help states and communities reach their energy efficiency goals in the building sector.

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