Accessory Dwelling Units
Look up your address in the search field above to check if it's in one of the 5 pilot areas and it's within a RS-2, RS-3, RT, or RM zoning district.
Accessory dwelling units (ADUs) are now legal in Chicago from Steven Vance on Vimeo.
Basic info
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.
Get building
The first permits can be applied for and issued on May 1, 2021.
Learn about ADUs via text
We're trying something new. Our new ADU texting service will keep you informed as we count down to the ADU permit application process opening on May 1, 2021. Every week from now until the end of May we'll send you tips and info about ADUs in Chicago.
You can reply and ask questions via text, too!
We're using Subtext for this - read their privacy policy.
Data Notes
Where are the most eligible properties?
There are five pilot areas: Southeast, South, West, Northwest, and North. Based on our estimation there are 92,322 eligible properties*. Use the Property Finder tool within each Place Snapshot (linked below) to map and download a list of these properties. They are spread across the pilot areas like so:
| Pilot area | Quantity |
|---|---|
| Southeast | 10,030 |
| South | 37,279 |
| West | 9,509 |
| Northwest | 15,348 |
| North | 20,156 |
Data notes
A plurality of these properties (49.2%) are in RS-3 zoning districts; 31.1% are in RS-2, and 15.1% are in RT-4. The remaining ~4.6% are in the 7 other "R" zoning districts.
* For our analysis, we included only these property classes (defined by the Cook County Assessor) that have a residential component: 2-11, 2-12, 2-13, 2-25, 3-13, 3-14, 3-15, 3-18, 3-91, 3-96, 4-18, 9-00, 9-13, 9-14, 9-15, 9-18, 9-91, 9-96, 9-97, 2-02, 2-03, 2-04, 2-05, 2-06, 2-07, 2-08, 2-09, 2-34, 2-78.
We also excluded condo buildings. Condo associations are allowed to participate, but the legalities and likelihood of doing so is up to each association and their rules. Vacant lots were excluded, too; a backyard house is allowed to be built first on a vacant lot in only the North (203 vacant lots) and Northwest (593 vacant lots) pilot areas.