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 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.
- 2021
- On May 9, 2023 the Capital Development Board voted to move the Illinois Energy Code to the 2021 International Energy Conservation Code with Illinois amendments. Proposed administrative rules will now go to the Joint Committee on Administrative Rules (JCAR). The new Code will be effective when approved by JCAR. This process can take from 90 days to a year to complete. The proposed rulemaking process officially begins when the proposed rules are published in the Illinois Register. A link will be provided on this page once the rules are published. The date of Register publication begins the First Notice period, during which the agency proposing the rulemaking must accept comments from the affected public. First Notice must continue for at least 45 days.