I wrote this summary of the ADU changes this proposed ordinance (O2023-2075) would implement (with my commentary in parentheses).

Before you read on, though, please sign the Urban Environmentalists Illinois petition to show your support for allowing ADUs citywide.

  • It allows ADUs citywide (this is the most important change to speed up adoption)
  • Expands to B and C1, C2 zoning districts (this is important because there are thousands of residential-only properties that are incorrectly zoned in B and C districts which don’t allow ADUs)
  • It also allows ground floor commercial conversions but only if 40% of more of the property length is commercial space.
  • It allows a property owner to have both an interior ADU and a backyard house ADU (currently you can have one or more interior ADUs or a backyard house)
  • It removes the 700 s.f. cap on floor area in backyard houses.
  • It allows property owners who want to build a coach house to ask the zoning administrator to waive parking requirements for the principal building. 
  • It would require a special use from the ZBA to establish an ADU in RS-1 and RS-2 zoning districts. These are much less common than the other R zoning districts and 0 ADUs have been permitted in those districts since May 1, 2021. 
  • It allows the property owner OR the city to notify the alder of a proposed ADU permit application. 
  • It eliminates the need for the property owner to notify their two adjacent neighbors. 
  • It doesn’t change the affordability requirements when proposing to build 2 or more interior ADUs. 
  • It eliminates the restrictions in the 3 southern limit areas that limited the number of ADU permits per block per year (this restriction ended up having no effect due to little demand in those areas). 
  • It eliminates the requirement that to build a coach house at a 1-3 unit house it had to be owner occupied (only in the 3 southern pilot areas, again this restriction ended up having no effect due to little demand in those areas). 

The changes would take effect 120 days after passage. It’s no guarantee that all of these will remain in the final version!

The ADU program in Chicago needs this. As I pointed out in my comment to the Chicago City Council Committee on Zoning, Landmarks, and Building Standards, the number of ADU permits has been declining since December 2022.