Illinois Building Permits
Building permits in Illinois are issued by cities and counties, not the state, so the rules depend on where your home is. These are the Illinois city we cover: Chicago.
Illinois Permit Activity at a Glance
Across the city below, we counted 7,366 issued permits for the home projects we track between October 30, 2025 and October 30, 2026. The counts come straight from each city's open permit data and are refreshed monthly. The busiest category was roofing work in Chicago, with 2,791 permits. Where the data includes an application date, the fastest median time from application to issue was 2 days (roofing in Chicago) and the slowest was 37 days (HVAC in Chicago).
Chicago Building Permits
5 project guides · 7,366 permits in 12 months · Chicago Department of Buildings
In Chicago, residential permits are issued by the Chicago Department of Buildings. Our counts use the city's Chicago Building Permits dataset. Short answers for each project we cover:
- Roof replacement: Depends on slope. On a house or other residential building up to 4 stories, repairing, recovering or replacing a roof with a pitch of at least 2:12 needs no building permit. Low-slope (flat) roofs and any structural repair need a permit, usually an Express Permit, with an Illinois-licensed roofing contractor doing the work.
- AC or furnace replacement: Not for in-kind swaps. In a residential building up to 4 stories, repairing or replacing a furnace, boiler or air conditioner in-kind (same type, size and shape) needs no building permit. A new system or a replacement that is not in-kind needs a permit, which the Express Permit Program covers with load calculations.
- Solar panel installation: Yes. New small rooftop solar systems up to 13.44 kW inverter output can use Chicago's Express Permit Program, with drawings and calculations from an Illinois-licensed architect or structural engineer. Larger systems, roofs over 40 feet and some ballasted systems need a standard permit.
- New fence: Sometimes. No building permit is needed for a fence no more than 5 feet high (measured on both sides) that meets the Chicago Zoning Ordinance. Taller fences use the Express Permit Program; front-yard fences are limited to 4.5 feet, or 6 feet if at least 80% open, and anything over 6 feet needs zoning approval.
- New deck or porch: Usually yes. A permit is needed for most porch and deck work. The exceptions are in-kind replacement of non-structural parts (deck boards, treads, pickets) and in-kind repair or replacement of a whole porch, deck or stair system no more than 6 feet above ground with a landing of 50 sq ft or less.
| Project Guide | Permit Needed? | Permits in 12 Months | Median Days to Issue |
|---|---|---|---|
| Chicago Roofing Permits | Depends on slope | 2,791 | 2 |
| Chicago HVAC Permits | Not for in-kind swaps | 401 | 37 |
| Chicago Solar Panel Permits | Yes | 1,615 | 10 |
| Chicago Fence Permits | Sometimes | 1,209 | 2 |
| Chicago Deck Permits | Usually yes | 1,350 | 13 |
How to Use These Illinois Guides
Start with the city that issues permits for your address. If you live outside city limits, your county or township usually handles permits instead, and its rules can differ from the city pages here. Each project guide quotes the official rule, lists any fee the city publishes, and links to the source so you can confirm it before you start work. Permit counts show how often each kind of job is permitted locally, and median days to issue show how long a typical application took over the last 12 months. Rules and fees change, so treat the official source as final and call the permit office if your project is unusual.
Data last refreshed October 30, 2026.