Illinois Permit & Stamping Requirements
Requirements vary by region, code cycle, seismic zone, and wind or snow load. Here is what typically drives design for Illinois projects.
What Drives Design in Illinois
Illinois projects are governed primarily by ground snow load and frost depth.
- ✓ Ground snow load per ASCE 7 and local amendments
- ✓ Frost depth and foundation design
- ✓ Roof framing capacity for drift loading
Exact code edition and local amendments vary by city and county. We confirm the specific requirements for your address before drafting.
Code in effect in Illinois
Illinois has long left the building code to each city and county, which adopt the edition of their choice, so two nearby towns can enforce different editions. State law also called for a statewide building code from January 1, 2025, so the code that applies depends on what your jurisdiction has adopted. Energy is statewide: the Illinois Energy Conservation Code, based on the 2024 IECC with Illinois amendments and ASHRAE 90.1-2022 for commercial work, took effect November 30, 2025. Chicago enforces its own construction and energy codes.
What to plan for
- ✓ The building code edition depends on your city or county, so we confirm the local adoption before drafting.
- ✓ The energy code is statewide: the 2024 IECC with Illinois amendments since November 30, 2025, with an optional Stretch Energy Code that some municipalities adopt.
- ✓ Chicago has its own construction and energy codes, separate from the rest of the state.
Code information last verified October 2026. Codes change, so we confirm the edition in force for your address before drafting.
Frequently asked questions about Illinois permits
Which building code applies in Illinois?
It depends on where the project is. Building codes have long been adopted locally, so each city or county may enforce a different edition, and Chicago has its own. We confirm the code your jurisdiction enforces before drafting.
Which energy code applies?
The Illinois Energy Conservation Code, based on the 2024 IECC with Illinois amendments, applies statewide from November 30, 2025. Chicago enforces its own energy code.
Sample Work & Other States
Foundation Plan
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Roof Framing Plan
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