Can I Build Garage Conversion in Chicago, IL? (2026)
Find out if you can build a garage conversion in Chicago, IL. Rules, permit requirements, costs, and next steps.
Whether garage conversions to living space are permitted in Chicago, IL has not been confirmed — contact the local building department or see the official source before proceeding.
Converting an attached or detached garage into living space in Chicago, IL is a popular way to add an ADU or additional living area without new construction. Garage conversion regulations in Chicago require verification with the local building department. A key consideration: whether replacement parking is required for a garage-to-ADU conversion has not been confirmed — check with the building department.
Garage Conversion Rules in Chicago
Garage Conversion Rules in Chicago: Allowed: Status not confirmed — see official source. Replacement parking required: Status not confirmed — see official source. All garage conversions to habitable space require a building permit. The converted space must meet minimum habitable room standards (typically 7 ft ceiling height, egress window, insulation, and ventilation).
Costs & Fees
Garage conversion permit fees in Chicago are typically based on project valuation. Contact the local building department at (312) 744-3449 for current fees. Conversion costs typically range $20,000–$80,000 depending on scope (permits, labor, materials, utility connections).
Timeline
Permit timeline: typically 2-6 weeks for plan check. Construction: 2-4 months for a typical garage conversion.
Next Steps
Next steps for converting your garage in Chicago: 1. Determine if the conversion will be an ADU (separate unit with kitchen/bath) or additional living space. 2. Check replacement parking requirements for your zone. 3. Have a contractor assess structural requirements (ceiling height, foundation, utilities). 4. Submit plans and permit application to the local building department. 5. See the full ADU rules page for size limits and requirements if creating an ADU unit.
Chicago Department of Buildings
Phone: (312) 744-3449 · Verified July 6, 2026 · Source
Website: https://www.chicago.gov/city/en/depts/bldgs.html
Online Permits: https://www.chicago.gov/city/en/depts/bldgs/provdrs/permits.html
Frequently Asked Questions
Can I build an ADU in Chicago?
Yes. Chicago's ADU Ordinance, expanded citywide in July 2022, allows both attached ADUs (basement or attic conversions) and detached coach houses (rear-yard ADUs typically built over a garage). Owner-occupancy applies only where the principal building adding a conversion unit or coach house is a detached house — that detached house must be owner-occupied at the time of pre-certification, and only within the designated RS Areas, not citywide. No replacement parking is required. A building permit from the Chicago Department of Buildings is required.
What is a coach house in Chicago, and is it the same as an ADU?
Yes. In Chicago, a coach house is the traditional term for a detached ADU — typically a 1- or 2-story structure built over a rear garage, accessed from the alley. Chicago's ADU Ordinance specifically authorizes coach houses up to 1,000 sqft and 22 ft tall. They are built in the rear yard, behind the principal building. Chicago has a rich history of coach houses from the late 19th and early 20th centuries.
How do I find the zoning of my Chicago property?
Use the City of Chicago Zoning Map at gisapps.chicago.gov/ZoningMapWeb/ — enter your address to find zone designation, applicable district standards, and special overlay zones. You can also check the Chicago Zoning Ordinance (Title 17) at codelibrary.amlegal.com.
Are short-term rentals allowed in Chicago?
Yes, with a license. The Chicago Shared Housing Ordinance (effective 2016) requires a Vacation Rental License or Shared Housing Host Registration ($125/year). Properties in buildings where the condo or co-op association has voted to ban short-term rentals are prohibited. Chicago collects a 4.5% Shared Housing Surcharge plus state hotel tax.
What are the setbacks for a standard Chicago bungalow lot?
In RS-3 (the most common single-family zone for Chicago bungalows), setbacks are: 15 ft front, 2 ft side (minimum — many have 2 ft on one side and 0 on the other with a shared driveway), and 30 ft rear. Chicago's standard lot is 25 ft wide by 125 ft deep. The rear yard is typically used for detached garages accessed from the alley.
Source: Chicago Department of Buildings — Building Regulations. Last verified April 3, 2026. View source