Accessory Dwelling Units
Basic ADU information
Starting April 1, 2026, ADUs are permitted in about 60% of the city's residential zoning land area — all multifamily (RT, RM) and mixed-use (B, C) districts by right, plus RS-zoned areas within an opt-in area.
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ADU permits by quarter
View more ADU statistics by ward, community area, and legislative district
More ADU resources
Discover our other ADU resources in our Knowledge Base
Previous ADU information ended March 31, 2026
The City of Chicago adopted an ordinance re-legalizing accessory dwelling units on Wednesday, December 16, 2020. It allows a backyard house or interior ADU at properties in one of the 5 pilot areas and also within a RS-2, RS-3, RT, or RM zoning district.
Properties with 5 or more units can have 2 or more interior ADUs, but no backyard house.