ADU Rules: Chicago vs Schaumburg
How do adu rules rules compare between Chicago, IL and Schaumburg, IL?
Chicago has fewer restrictions than Schaumburg.
Chicago, IL
Cook County
Chicago ADU Ordinance: permanent program effective April 1, 2026 citywide (with aldermanic opt-in for single-family RS zones). Pilot program active in 5 zones since 2021. Coach houses up to 1,200 sq ft.
View full Chicago rules →Schaumburg, IL
Cook County
Schaumburg's zoning ordinance does not broadly permit accessory dwelling units (granny flats, in-law suites) as a by-right use in most residential zoning districts. Illinois does not have a statewide ADU mandate. Creating a separate dwelling unit within or adjacent to a single-family home generally requires a zoning variation or special use permit. Conversions that add a kitchen to create a second independent living unit are typically not permitted without zoning relief.
View full Schaumburg rules →Key Facts Comparison
| Fact | Chicago | Schaumburg |
|---|---|---|
| Program | Permanent ordinance effective April 1, 2026 | - |
| Coverage | Citywide with aldermanic opt-in for RS zones | - |
| Pilot Zones | 5 zones pre-opted-in since 2021 | - |
| Max Size | 1,200 sq ft or 50% of primary dwelling | - |
| Height | 22 feet maximum | - |
| South/West/SW | 2 permits/block/year cap; owner-occupancy required | - |
| By-Right ADUs | - | Not permitted in most zones |
| State Mandate | - | Illinois has no ADU mandate |
| Approval Path | - | Variation or special use permit |
| Key Trigger | - | Adding a kitchen creates second unit |
| Review Body | - | Zoning Board of Appeals/Plan Commission |
Highlighted rows indicate differences between cities.
Chicago FAQ
Can I build an ADU on my property in Chicago?
Chicago ADU Ordinance: permanent program effective April 1, 2026 citywide (with aldermanic opt-in for single-family RS zones). Pilot program active in 5 zones since 2021. Coach houses up to 1,200 sq ft.
What are the size limits for an accessory dwelling unit in Chicago?
Program: Permanent ordinance effective April 1, 2026. Coverage: Citywide with aldermanic opt-in for RS zones. Pilot Zones: 5 zones pre-opted-in since 2021. Max Size: 1,200 sq ft or 50% of primary dwelling.
Schaumburg FAQ
Can I build a granny flat in my backyard in Schaumburg?
Not by right. Schaumburg's zoning generally allows only one dwelling unit per single-family lot. A detached ADU would require a variation or special use permit from the Zoning Board of Appeals, and approval is not guaranteed.
Can I add an in-law suite to my house?
You can add a bedroom, bathroom, and living area for family members, but adding a separate kitchen creates a second dwelling unit under the zoning ordinance, which is not permitted by right. Consult the Community Development Department before planning.
Does Illinois require cities to allow ADUs?
No. Unlike California and other states, Illinois does not have a statewide ADU mandate. Each municipality sets its own rules. Schaumburg currently restricts ADUs in most residential zones.
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