Issue Overview
First deemed illegal in 1957, the City of Chicago is slowly reversing course on outlawing Additional Dwelling Units (ADU). In December 2020, City Council approved an ordinance that would allow for ADU permits in specific zones. In 2023, legislation was introduced to expand the pilot program city-wide. In 2024, a substitute bill was introduced to accommodate some amendments offered within City Council. In July 2025, the Zoning Committee approved an ordinance to allow citywide ADUs but the ordinance was stalled in City Council.
What is an ADU?
An Accessory Dwelling Unit (ADU) is an expansion to existing property, such as a garden unit in the basement or turning an attic space into a rental unit. These can include coach houses or a flat created on a property lot, not necessarily attached to the primary residence. In Chicago, there is an affordability component for property owners seeking to add more than one unit to a property.
Legislative Outlook
In May 2021, the city began accepting applications for ADUs in specific pilot zone areas. It is estimated that roughly 400 ADUs have been created since 2021. Of those units, about 25-30 units are affordable (60 % AMI).
The proposed version that passed Zoning in July 2025 is similar to the pilot program. However, an alderperson may opt out of different restrictions, such as owner occupancy requirements and limits to how many ADUs can be built per block per year. So for RS-11, one unit can be built per block per year, for RS-2, two units can be built per block per year, for RS-3, three units can be built per block per year, which helps to ensure a slow rollout. These are helpful in wards where the alderperson is very supportive of ADUs.
The ADU ordinance was deferred (D&P) by Alders Quinn (13) and Mitchell (7) after several compromises were made. Ultimately, many Council members want to retain control of their wards in RS-zoned areas. There is also continued concern about increased parking within neighborhoods already stretched for existing resident parking.
Last year, Ald. Lawson’s version of the ADU ordinance included special use permits in RS-1 and RS-2 (requiring Alder involvement). This version from last year likely would have passed, but the mayor’s office has expressed a continued desire for ADUs to be permitted in all residential districts. The last round of negotiations included administrative adjustments to RS districts.
Next Steps
On July 16, 2025, the full City Council vote was too close to pass. While this caused a delay, it presents an opportunity to build support, share educational materials and engage further with opponents to help ensure full passage.
Our Stance
Accessory Dwelling Units help increase the housing supply, and REALTORS® firmly support policies that encourage building and construction.
News
Issue Updates
Updated 7/17/25
On July 15, 2025, the City Council’s Zoning Committee approved an ordinance to allow Accessory Dwelling Units (ADUs) citywide without requiring a zoning change. The ordinance went before the full City Council for final approval on July 16, 2025, where it was ultimately delayed.
Updated 7/15/25
In an op-ed for the Chicago Tribune, our President Erika Villegas and President-Elect Lutalo McGee made the case for citywide ADUs, highlighting ADUs as a practical step toward easing Chicago’s housing shortage. With inventory down 58% over the last decade and rent nearly doubling, the need for action is clear. Read the full piece here.
Updated 7/23/24
In June 2024 the Zoning Committee hosted a subject matter hearing regarding the pilot ADU program. Alderman Bennett Lawson, lead sponsor, would like to pass the legislation to begin offering property owners throughout the city an option for ADUs. Further supporting an increase of much-needed housing stock in Chicago. It is expected that the Zoning Committee will vote on a city-wide ADU program within the coming months.
- RS stands for Residential Single Unit Districts: 1,2 and 3 are single-family/detached with different minimum lot sizes. RT stands for Residential Two-Flat, Townhouse and Multi-Unit. RM stands for Residential Multi-Unit, Detached, Townhouses and Multi-Unit Buildings ↩︎