Illinois building code
Illinois has adopted rolling (current or most recent preceding edition; as of 2026-07 that is 2024 or 2021 IBC) IBC based on 2024/2021 IBC. The table below lists the governing edition for every discipline a plan check touches, followed by the Illinois cities and counties that amend it locally.
- Current edition
- Post-PA 103-0510 statewide baseline (rolling 'current or most recent preceding' ICC editions, effective 2025-01-01) + 2024 Illinois Energy Conservation Code (eff. 2025-11-30)
- Prior edition
- No statewide building code (pure local-option/home rule); energy: 2021 Illinois Energy Conservation Code
- Code authority
- Illinois Capital Development Board (CDB); Illinois Department of Public Health (plumbing); Office of the Illinois State Fire Marshal (fire/life safety)
Edition changeover: Projects with a complete application on or before 2024-12-31 (building regime); 2025-11-29 (2021 ILECC) may still be reviewed under the No statewide building code (pure local-option/home rule); energy: 2021 Illinois Energy Conservation Code.
Adopted code by discipline
| Discipline | Adopted code | Local amendment |
|---|---|---|
| Building | rolling (current or most recent preceding edition; as of 2026-07 that is 2024 or 2021 IBC) IBC based on 2024/2021 IBC | n/a |
| Residential | rolling (current or most recent preceding edition; as of 2026-07 that is 2024 or 2021 IRC) IRC based on 2024/2021 IRC | n/a |
| Existing buildings | rolling (current or most recent preceding edition; as of 2026-07 that is 2024 or 2021 IEBC) IEBC based on 2024/2021 IEBC | n/a |
| Fire | 2015 (NFPA 101) OSFM Fire Prevention and Safety rules (41 Ill. Adm. Code 100) adopting NFPA 101 Life Safety Code based on 2015 NFPA 101 | n/a |
| Electrical | rolling (current or most recent preceding edition; as of 2026-07 that is 2023 or 2020 NEC) NEC (NFPA 70) based on 2023/2020 NEC | n/a |
| Plumbing | 2014 (last major amendment, 38 Ill. Reg. 9940, eff. 2014-04-24) Illinois Plumbing Code (77 Ill. Adm. Code 890) | n/a |
| Energy | 2024 Illinois Energy Conservation Code (ILECC, 71 Ill. Adm. Code 600) based on 2024 IECC | n/a |
| Accessibility | 2018 Illinois Accessibility Code (71 Ill. Adm. Code 400) | n/a |
Overlays that can apply
Mapped hazard and district overlays stack on top of the adopted code. These are the overlays recorded for Illinois. They apply by parcel, not jurisdiction-wide, so confirm the parcel before assuming one is in play. Check CAL FIRE's fire hazard severity viewer and FEMA's flood map service.
- FEMA mapped flood hazard area
- Local stretch energy code
Sources
- https://cdb.illinois.gov/business/codes.html
- https://cdb.illinois.gov/business/codes/buildingcodesregulations.html
- https://my.ilga.gov/legislation/ilcs/fulltext?DocName=002031050K10.09-1
- https://cdb.illinois.gov/business/codes/illinois-energy-codes.html
- https://energysense.uillinois.edu/energy-code/illinois-energy-conservation-code/
- https://sfm.illinois.gov/resources/life-safety-code.html
- https://www.ilga.gov/agencies/JCAR/Sections?PartID=07700890
- https://dceo.illinois.gov/content/dam/soi/en/web/dceo/cdb/business/codes/illinoisaccessibilitycode/documents/2018-illinois-accessibility-code.pdf
- https://cdb.illinois.gov/business/codes/illinois-codes-faq.html
- https://www.iccsafe.org/adoptions
Common questions
What building code does Illinois use?
Illinois uses rolling (current or most recent preceding edition; as of 2026-07 that is 2024 or 2021 IBC) IBC based on 2024/2021 IBC. It is administered by the Illinois Capital Development Board (CDB); Illinois Department of Public Health (plumbing); Office of the Illinois State Fire Marshal (fire/life safety). The prior edition was No statewide building code (pure local-option/home rule); energy: 2021 Illinois Energy Conservation Code.
Do cities in Illinois amend the state code?
Local amendments are adopted by ordinance at the city or county level. Confirm with the building department that reviews your permit.
Which edition applies to a permit already in review in Illinois?
Projects with a complete application on or before 2024-12-31 (building regime); 2025-11-29 (2021 ILECC) may still be reviewed under the No statewide building code (pure local-option/home rule); energy: 2021 Illinois Energy Conservation Code.
Check a plan set against Illinois code
Knowing the adopted edition is the easy half. Architechtura reads your drawings, resolves which of these provisions actually apply to the project, and returns the corrections a plan checker would write up, each one cited to the section it came from.
Your first check is free, no card required.
Compiled from published state and municipal adoption ordinances. Local governments amend their codes on their own schedule, and a pending ordinance can change what applies to your permit. Confirm the governing edition with the building department before you submit. This page is reference information, not a code determination.