Illinois building departments
Find local permit offices, inspection services, and official resources across Illinois.
How permitting works in Illinois
Local codes with an IRC/IBC minimum since 2025. Illinois codes are adopted by municipalities and counties, but since January 1, 2025 they must be at least as strict as the IRC and IBC. Where no local code exists, new homes must still meet the IRC.
A county name is only a geographic starting point. Depending on the address, a city, town, borough, township, or county office may issue your permit. How to check who issues your permit.
Illinois building codes and licensing
- Residential code
- No single state residential code. Since Jan 1, 2025 local codes must be at least as stringent as the IRC; with no local code, new homes follow the IRC
- Commercial code
- Since Jan 1, 2025 local codes must be at least as stringent as the IBC/IEBC; with no local code, the current or preceding IBC/IEBC applies
- Outside city limits
- Where a city or county has not adopted a building code, new homes must still meet the IRC under the Residential Building Code Act, and new or substantially improved commercial buildings must be inspected by a qualified inspector against the IBC/IEBC.
- Contractor licensing
- IDFPR licenses roofing contractors under the Roofing Industry Licensing Act. Plumbers are licensed and plumbing contractors registered with IDPH under the Illinois Plumbing License Law. Illinois Department of Financial and Professional Regulation (roofing) and Illinois Department of Public Health (plumbing) (opens in a new tab)
What is different in Illinois
- The 2024 Illinois Energy Conservation Code (2024 IECC with Illinois amendments) took effect November 30, 2025 for both residential and commercial buildings.
- The Illinois Plumbing Code applies statewide, and plumbing ads must show the plumbing license number; misuse of license numbers is a Class A misdemeanor.
- Municipalities and counties that adopt or amend a building code must report the code title, edition and local amendments to the Capital Development Board at least 30 days before it takes effect.
Illinois department guides
Browse Illinois counties
Adams CountyAlexander CountyBond CountyBoone CountyBrown CountyBureau CountyCalhoun CountyCarroll CountyCass CountyChampaign CountyChristian CountyClark CountyClay CountyClinton CountyColes CountyCook CountyCrawford CountyCumberland CountyDeKalb CountyDe Witt CountyDouglas CountyDuPage CountyEdgar CountyEdwards CountyEffingham CountyFayette CountyFord CountyFranklin CountyFulton CountyGallatin CountyGreene CountyGrundy CountyHamilton CountyHancock CountyHardin CountyHenderson CountyHenry CountyIroquois CountyJackson CountyJasper CountyJefferson CountyJersey CountyJo Daviess CountyJohnson CountyKane CountyKankakee CountyKendall CountyKnox CountyLake CountyLaSalle CountyLawrence CountyLee CountyLivingston CountyLogan CountyMcDonough CountyMcHenry CountyMcLean CountyMacon CountyMacoupin CountyMadison CountyMarion CountyMarshall CountyMason CountyMassac CountyMenard CountyMercer CountyMonroe CountyMontgomery CountyMorgan CountyMoultrie CountyOgle CountyPeoria CountyPerry CountyPiatt CountyPike CountyPope CountyPulaski CountyPutnam CountyRandolph CountyRichland CountyRock Island CountySt. Clair CountySaline CountySangamon CountySchuyler CountyScott CountyShelby CountyStark CountyStephenson CountyTazewell CountyUnion CountyVermilion CountyWabash CountyWarren CountyWashington CountyWayne CountyWhite CountyWhiteside CountyWill CountyWilliamson CountyWinnebago CountyWoodford County
Planning a project in Illinois?
Start with what the model codes say, then confirm local rules with the department that serves your address.