Illinois Energy Conservation Code
(20 ILCS 3125/15)
Privately Funded Commercial Facilities must comply with the Illinois Energy Conservation Code per 20 ILCS 3125. See Subpart C of the Illinois Energy Code for more information. The 2021 edition of the IECC as amended went into effect on 1/1/24.
Residential Buildings must comply with Illinois Energy Conservation Code per 20 ILCS 3125. See Subpart D of the Illinois Energy Code for more information. The 2021 edition of the IECC as amended went into effect on 1/1/24.
| The Illinois Energy Conservation Code (Base Code) is available online at https://codes.iccsafe.org/ Amendments to the Model Code are shown below. | 
- 2024- The 2024 Illinois Energy Conservation Code (Base Code) will become effective 11/30/25. The final code should be available on ICC's website sometime in November.
- Illinois Specific Amendments
- 2024 IECC Cost Effective Analysis
 
