International Energy Conservation Code IECC
Minimum energy efficiency for building envelopes, mechanical systems, service water heating, electrical power, and lighting. Has a Residential and a Commercial half.
Overview
Minimum energy efficiency for building envelopes, mechanical systems, service water heating, electrical power, and lighting. Has a Residential and a Commercial half.
Publisher
International Code Council (ICC)
Latest edition
2024
First published
1998
Cycle
Every 3 years
Why it matters
IECC edition sets wall and roof U-values, window SHGC limits, and ventilation-system efficiency floors. The 2021 edition was a step-change; several states rejected it outright.
Adoption by edition
Each row is one published edition, with the states (and DC) that have adopted it as the statewide minimum. Click a postal code to jump to that state's code wiki.
| Edition | States | Adopting jurisdictions |
|---|---|---|
| 2025 | 1 | CA |
| 2024 | 8 | CO · GA · IL · NV · NY · ND · OR · RI |
| 2021 | 18 | CT · FL · LA · ME · MD · MA · MI · MN · MT · NJ · NM · OH · TN · UT · VT · VA · WA · WI |
| 2018 | 7 | AK · DE · HI · ID · NE · NH · PA |
| 2017 | 1 | DC |
| 2015 | 3 | NC · TX · WV |
| 2012 | 2 | IA · KY |
| 2010 | 1 | IN |
| 2009 | 3 | AR · SC · SD |
| 2006 | 1 | OK |
Local amendments
States commonly strip the EV rough-in, renewable-ready, and solar-ready provisions, or raise permissible U-values to match their climate.