Garage Conversions: Arlington Heights vs Chicago
How do garage conversions rules compare between Arlington Heights, IL and Chicago, IL?
Chicago has fewer restrictions than Arlington Heights.
Arlington Heights, IL
Cook County
Converting a garage to living space in Arlington Heights is heavily restricted. The Village zoning ordinance requires residential properties to maintain a minimum number of enclosed parking spaces. Converting a garage to habitable space typically requires providing replacement off-street parking and obtaining building permits for the conversion.
View full Arlington Heights rules →Chicago, IL
Cook County
Chicago authorizes garage conversions to coach houses (detached ADUs) and conversion units (attic/basement ADUs) under the Additional Dwelling Unit Ordinance. The pilot ordinance (effective May 2021) was made permanent and city-wide by Ordinance SO2024-0008918, which the City Council passed 46-0 on September 25, 2025, with permits accepted starting April 1, 2026. ADUs are now allowed in single-family zones within the original pilot areas plus all multifamily zones citywide (except downtown).
View full Chicago rules →Key Facts Comparison
| Fact | Arlington Heights | Chicago |
|---|---|---|
| Replacement Parking | Must provide enclosed off-street parking | - |
| Minimum Parking | 2 enclosed spaces required | - |
| Permit Required | Yes, building permit | - |
| ADU Restriction | Cannot create separate dwelling | - |
| Building Code | Must meet habitable space standards | - |
| Ordinance | - | SO2024-0008918 (passed 9/25/2025) |
| Effective Citywide | - | April 1, 2026 |
| Coach House Height | - | 22 ft max; rear 50% of lot |
| Parking | - | No additional spaces required |
| Labor Standard | - | Reg. Apprenticeship Program (coach houses) |
Highlighted rows indicate differences between cities.
Arlington Heights FAQ
Can I convert my garage to a living room in Arlington Heights?
Only if you provide replacement enclosed off-street parking on the property. The zoning code requires at least two enclosed parking spaces per single-family home. You would need to build a new garage before converting the existing one.
What building code requirements apply to a garage conversion?
The converted space must meet all residential building code standards including insulation, egress windows, minimum ceiling height of 7 feet, HVAC, electrical upgrades, and fire separation from any remaining garage area.
Can I convert my garage into a rental apartment?
No. Creating a separate dwelling unit in a garage would violate the Village's zoning restrictions on accessory dwelling units. A special use permit would be required, and approval is not guaranteed.
Chicago FAQ
Can I legally convert my Chicago garage to a coach house?
Yes, in eligible zones. As of April 1, 2026, Chicago's permanent Additional Dwelling Unit Ordinance (SO2024-0008918) allows coach houses citywide in single-family zones within the original pilot areas plus all multifamily zones (except downtown), with a 22-foot height limit in the rear 50% of the lot.
Do I need a permit to remodel or convert my Chicago garage to living space?
Yes. The Chicago Department of Buildings requires a building permit for any change of use from garage to habitable space, with plan review under Title 14X (Chicago Building Code). For ADU/coach house conversions, a pre-certification from the Department of Housing is required first.
Do I need additional parking after converting my Chicago garage?
No. The Additional Dwelling Unit Ordinance does not require additional off-street parking when adding an ADU, even when the conversion eliminates an existing garage.
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