Illinois · Penalties if you skip one

What you can build without a permit in Illinois

By Mario Bailey Last checked · 18 official sources

Quick answer

Across the 2 Illinois jurisdictions we have verified, 0 of 23 project rules need no permit at all, 9 turn on a size or scope condition the jurisdiction publishes, and 14 require a permit regardless. Pool work is where the answer most often comes with a published condition rather than a flat yes: 2 of the 2 jurisdictions that answer publish one. The numbers are not statewide: pool thresholds alone run from 24 to 48 inches depending on the jurisdiction.

How to read this page

"No permit" means the jurisdiction publishes that the work needs no building permit. "Depends" means it publishes a size, height, depth, cost or scope condition that decides the answer, quoted in its own words in the last column; the number beside it is the figure that condition turns on, and which side of the number is exempt is stated by the condition, not by us. Exempt from a building permit is not exempt from zoning, setbacks, height limits, flood rules, an HOA, or a separate electrical, plumbing or mechanical permit, and several of the conditions below say exactly that.

Pool

All 2 make the pool answer turn on a size or scope condition the jurisdiction publishes, and the 2 that state a number publish figures from 24 to 48 inches.

Jurisdiction Permit Published figure What the rule says
Chicago Depends 48 inches pools with water depth greater than 48 inches on a lot with 1 to 3 residential units require a full building permit with licensed architect or engineer plans; shallower pools with volume under 5000 gallons may be exempt.
Cook County Depends 24 inches prefabricated above-ground pools accessory to detached single-family dwellings.

Shed

All 2 make the shed answer turn on a size or scope condition the jurisdiction publishes, and the 2 that state a number publish figures from 81 to 150 sq ft.

Jurisdiction Permit Published figure What the rule says
Chicago Depends 150 sq ft single-story detached tool or storage shed under 150 sq ft and not more than 15 ft tall with no plumbing does not require a permit.
Cook County Depends 81 sq ft prefabricated storage containers.

Fence

1 of 2 makes the fence answer turn on a size or scope condition the jurisdiction publishes. Cook County requires a permit for fence work regardless of size.

Jurisdiction Permit Published figure What the rule says
Chicago Depends 5 feet fence 5 ft or less in height on private residential property does not require a permit; fences over 5 ft require a permit.
Cook County Permit required Cook County's building permits apply ONLY to unincorporated Cook County.

Patio

1 of 2 makes the patio answer turn on a size or scope condition the jurisdiction publishes. Cook County requires a permit for patio work regardless of size.

Jurisdiction Permit Published figure What the rule says
Chicago Depends 30 inches at-grade noncombustible (concrete or brick) patios not more than 30 inches above adjacent grade, not over a basement or story below, and not in the public way are exempt; taller, over-basement, public-way, or roofed/covered patios require a permit.
Cook County Permit required Cook County treats patios as flat work, and its Flat Work Permit Requirements flyer states plainly that adding or modifying impervious surfaces such as drives, patios and walls requires a permit and drawings.

Bathroom Remodel

All 1 makes the bathroom remodel answer turn on a size or scope condition the jurisdiction publishes.

Jurisdiction Permit Published figure What the rule says
Chicago Depends Permit triggers are set by each municipality's ordinance; there is no state building-permit rule.

EV Charger

All 1 makes the EV Charger answer turn on a size or scope condition the jurisdiction publishes.

Jurisdiction Permit Published figure What the rule says
Chicago Depends Electrical permits for a hardwired Level 2 charger are a municipal matter in Illinois; no state statute imposes a permit requirement for installing one in an existing home.

Water Heater

All 1 makes the water heater answer turn on a size or scope condition the jurisdiction publishes.

Jurisdiction Permit Published figure What the rule says
Chicago Depends Whether a permit is required is decided by the municipality; Illinois has no statewide permit requirement.

If the work is already built

Illinois has no state building-permit penalty statute for private residential work; building permits and penalties are municipal. The Illinois Municipal Code authorizes corporate authorities to pass ordinances 'with such fines or penalties as may be deemed proper,' and provides that 'No fine or penalty, however, except civil penalties provided for failure to make returns or to pay any taxes levied by the municipality shall exceed $750,' with imprisonment under 65 ILCS 5/1-2-9 (only for failure to pay a fine) capped at 6 months per offense.

Illinois penalties, the after-the-fact path, and what the statute actually says

The 23 answered rules come from 18 official sources, each linked from the permit page behind every jurisdiction name. See the full picture for the state on the Illinois permit requirements page, or the national view of which projects need a permit at all on Do you need a building permit?

This page compiles what each Illinois jurisdiction publishes, with a last checked date. It is not legal advice, and a project that is exempt from a building permit can still need zoning approval or a trade permit. Confirm with the office linked from the jurisdiction's page before you build.