St. Clair County, Illinois Roofing Permit Regulations and County Ordinances for Unincorporated Areas

St. Clair County, Illinois Roofing Permit Requirements

St. Clair County, Illinois, has a Building & Zoning Department that handles permit requirements for properties within its jurisdiction. This department is responsible for ensuring orderly development and enforcing zoning ordinances, particularly in unincorporated areas.

For properties in unincorporated areas of St. Clair County, a building permit is generally required for roofing work that goes beyond ordinary repairs. Ordinary repairs are defined as work that does not involve cutting away structural elements, altering egress, or changing essential plumbing, electrical, or mechanical systems.

The St. Clair County Building & Zoning Department has adopted the International Building Code 2012 with amendments for unincorporated areas.

To apply for a building permit, you will need to submit a written application, which includes a description of the work, the property's legal description or street address, and the intended use and occupancy of the structure. For residential structures, one set of scaled plans is typically required, along with an Application for Zoning Compliance. Commercial or industrial projects require plans and specifications designed by a licensed Illinois architect.

Before applying for a permit, it is necessary to obtain an assigned address from the 9-1-1 Coordinating Office. Additionally, for residential projects, you may need to generate an Energy Code Compliance Certificate using energycodes.gov/rescheck or energycodes.gov/comcheck for commercial projects.

Permit fees vary based on the project. It is important to note that all incomplete permit applications will be returned.

Inspections are a crucial part of the permitting process. Properties must be marked with an address, and the building permit must be posted. You are required to call 24 hours in advance to schedule an inspection, providing your permit number, construction address, and owner's name. Failing an inspection will result in a re-inspection fee.

Resources to Learn More

Note: The following state-wide building codes and regulations apply universally to all jurisdictions within Illinois, including St. Clair County.

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 City in St. Clair County

If your project is located within incorporated city limits, you will likely need to follow municipal ordinances rather than county rules. Select your city below to view local regulations.

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