State directory · IL · Midwest
Illinois building departments
This Illinois directory covers 102 Census county equivalents and local building-department guides. Illinois has substantial local variation. Identify the municipality, township, or county authority before relying on a statewide building-code assumption.
How permitting works in Illinois
Primarily local code adoption. A county name is a geographic index, not a promise that the county government issues every building permit. Many projects are handled by a city, town, township, borough, parish, regional office, or independent city.
Source-backed state research
Illinois Capital Development Board
Illinois changed its statewide building-code framework effective January 1, 2025. Local code officials remain the best source for a specific property, while state requirements and local amendments can both affect permitting.
Read the official state source ↗Researched local guides
Available department pages
Aurora · Kane County
Aurora Division of Building and Permits
Permits, inspections, zoning, and official contact information.
Champaign · Champaign County
Champaign Building Safety Division
Permits, inspections, zoning, and official contact information.
Chicago · Cook County
Chicago Department of Buildings
Permits, inspections, zoning, and official contact information.
Cook County · Cook County
Cook County Department of Building and Zoning
Permits, inspections, zoning, and official contact information.
Joliet · Will County
Joliet Building and Inspectional Services
Permits, inspections, zoning, and official contact information.
Naperville · DuPage County
Naperville Building Permits Department
Permits, inspections, zoning, and official contact information.
Rockford · Winnebago County
Rockford Construction and Development Services
Permits, inspections, zoning, and official contact information.
Waukegan · Lake County
Waukegan Building and Code Department
Permits, inspections, zoning, and official contact information.
Geographic coverage