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Illinois Energy Conservation Code
(20 ILCS 3125/15)
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 2021 edition of the IECC as amended went into effect on 1/1/24.
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 2021 edition of the IECC as amended went into effect on 1/1/24.
Residential Buildings must comply with IECC per 20 ILCS 3125. See Subpart D of the Illinois Energy Conservation Code for more information. The 2021 edition of the IECC as amended went into effect on 1/1/24.
- 2024
- The public proposal period for the 2024 Illinois Energy Conservation Code (Base Code) has begun and will remain open until 12/31/24. Additional information can be found on the 2024 Base Code Proposals page.