ADU Rules in Chicago, IL — 2026 Guide
Check if your Chicago property qualifies for an ADU in 20 seconds
Chicago ADU Rules at a Glance
Chicago is considered ADU-friendly. Here are the key regulations.
- Chicago launched an ADU pilot ordinance in 2020, expanded citywide in 2023.
- Coach houses and garage conversions are the most common ADU types.
- ADUs permitted up to 1,000 sqft on standard residential lots.
- Property must be owner-occupied to build an ADU under the current ordinance.
What ReadyPermit Checks for Chicago Properties
Enter any Chicago address and get an instant ADU feasibility analysis covering:
Zoning Compliance
Verify your Chicago lot is zoned for ADU construction under current IL and local rules.
Setbacks & Coverage
Check required setbacks, lot coverage limits, and height restrictions for your specific parcel.
ADU Size Limits
Calculate the maximum ADU square footage allowed based on your lot size and primary dwelling.
Permit Requirements
Understand what permits and approvals Chicago requires before you can break ground.
Flood & Hazard Zones
Identify if your property falls in a flood zone, fire zone, or other hazard overlay.
Lot & Parcel Data
Pull parcel boundaries, lot dimensions, and existing structures from county records.
Check Your Chicago Property Free
Enter your address below. In under 20 seconds you will know if your Chicago lot qualifies for an ADU — no phone calls, no waiting.
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