Illinois Energy Conservation Code


The Illinois Energy Conservation Code requires design and construction professionals to follow the latest published edition of the International Energy Conservation Code (IECC) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Standard 90.1 "Energy Standard for Buildings except Low-Rise Residential Buildings" including amendments adopted by the Capital Development Board.

State Funded Facilities must comply with the IECC per 20 ILCS 3125.  See Subpart B of the Illinois Energy Conservation Code for more information.  The 2018 edition of the IECC went into effect on 7/1/19.

Privately Funded Commercial Facilities must comply with IECC per 20 ILCS 3125.  See Subpart C of the Illinois Energy Conservation Code for more information. The 2018 edition of the IECC went into effect on 7/1/19.

Residential Buildings must comply with IECC per 20 ILCS 3125. See Subpart D of the Illinois Energy Conservation Code for more information. The 2018 edition of the IECC went into effect on 7/1/19.

Additional information including training opportunities, interpretations and frequently asked questions can be found on the Illinois Environmental Protection Agency's web site.

Upcoming Training Opportunities for the 2018 Illinois Energy Conservation Code are being provided by the Smart Energy Design Assistance Center.  For more information, please use the following link, https://smartenergy.illinois.edu/upcoming-energycode-events.

Updates to the Illinois Energy Conservation Code