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Illinois Roofing Legislation, Codes, and Guidelines

State-Level Building Codes and Legislation for Roofing in Illinois

As of January 1, 2025, Illinois has implemented a statewide baseline building code requirement pursuant to Public Act 103-0510, which amended the Capital Development Board Act. This legislation mandates that all municipalities and counties in Illinois must adopt and enforce building codes that meet or exceed the minimum structural requirements of the International Code Council (ICC) standards, specifically the International Building Code (IBC) and the International Residential Code (IRC). Prior to this, Illinois did not have a unified statewide building code, and regulations were determined entirely at the local municipal or county level.

While the state now requires a baseline, local jurisdictions retain the authority to adopt their own specific editions (such as the 2018, 2021, or 2024 editions) and implement local amendments, provided those amendments do not reduce the structural requirements below the state-mandated baseline. Consequently, specific roofing requirements—such as those for ice and water shields, ventilation, and shingle layering—can still vary significantly between different cities, villages, and counties. Property owners and contractors must consult their local Authority Having Jurisdiction (AHJ) to confirm the specific code edition and local amendments applicable to their project.

Primary State Agency

The Illinois Capital Development Board (CDB) is the primary state agency responsible for the administration of the state's building code framework. Under the Capital Development Board Act (20 ILCS 3105), the CDB is tasked with identifying and publishing local building codes and ensuring that municipalities and counties comply with the requirement to report their adopted codes and amendments to the state.

Resources to Learn More

Select a County Below to Learn More About That Jurisdiction in Illinois

Permit rules operate within the above structure but can be nuanced at the county or municipal level. Select your local area below for specific ordinances, local codes, and direct links for your locality Building Department.