Can I Build ADU in Detroit, MI? (2026)
Find out if you can build a adu in Detroit, MI. Rules, permit requirements, costs, and next steps.
Yes, ADUs are allowed in Detroit, MI. California state law ensures by-right approval.
An Accessory Dwelling Unit (ADU) is a secondary housing unit on a residential lot — also called a granny flat, in-law suite, or backyard cottage. In Detroit, MI, ADUs are permitted by right under state law, making them one of the most accessible ways to add housing on your property. ADUs can be detached, attached to the main home, or created by converting an existing garage or accessory structure.
ADU Rules in Detroit
ADU Rules in Detroit: Detached ADU max size: 800 sq ft. Attached ADU max size: 600. Setbacks: 3 ft side, 4 ft rear. Owner-occupancy: No owner-occupancy requirement under current Detroit ADU ordinance. Detroit's land vacancy context encourages flexible occupancy to maximize use of distressed properties..
Costs & Fees
ADU permits in Detroit: Total estimated permit cost: $1,000-$4,500 total permit fees. Contact the Detroit Buildings, Safety Engineering and Environmental Department (BSEED) for current fee schedule.
Timeline
Detroit Buildings, Safety Engineering and Environmental Department (BSEED): ADU permits typically 6-10 weeks for plan review. Construction 3-8 months depending on contractor availability. Detroit's construction labor market has grown with the city's comeback.
Next Steps
Next steps for building an ADU in Detroit: 1. Review full ADU rules including size limits, setbacks, and parking. 2. Apply for an ADU permit through the Detroit Buildings, Safety Engineering and Environmental Department (BSEED) at https://detroitmi.gov/departments/buildings-safety-engineering-and-environmental-department/permits. 3. Hire a licensed contractor familiar with MI ADU requirements.
Detroit Buildings, Safety Engineering and Environmental Department (BSEED)
Frequently Asked Questions
Can I build an ADU on a vacant lot I bought from the Detroit Land Bank?
Yes, but it requires careful steps. Detroit Land Bank Authority (DLBA) properties purchased for side lot or development use may be subject to deed restrictions requiring improvement within a set timeline. To build a standalone ADU on an adjacent vacant lot, you would typically first consolidate the lots through the City of Detroit, then apply for a BSEED building permit for the ADU. Contact the Detroit Planning and Development Department to confirm consolidation requirements before purchasing.
What makes Detroit's ADU situation unique compared to growing cities?
Detroit is the nation's largest shrinking city, with roughly 25% of its land area now vacant. This means ADU opportunities in Detroit are different from cities like Austin or Denver. Rather than adding to congested neighborhoods, Detroit ADUs often serve as infill on empty lots, help rehabilitate underused carriage houses and garages, and contribute to the city's comeback strategy. The Detroit Land Bank Authority sells vacant lots at low prices specifically to encourage this kind of development.
Are short-term rentals (Airbnb) allowed in Detroit?
Yes. Detroit allows short-term rentals and requires an STR license ($100/year). Michigan Act 20 of 2023 prevents Detroit from banning STRs outright in residential zones, though Detroit may impose operational requirements. STR operators must have a Certificate of Occupancy and comply with Detroit's rental housing standards. Detroit's urban revival has made Corktown, Midtown, and the Riverfront attractive for Airbnb visitors.
I own a home in the Boston-Edison Historic District. Can I make exterior changes?
Yes, but you need a Certificate of Appropriateness from the Detroit Historic District Commission (HDC) before beginning any exterior alterations, including additions, siding changes, window replacements, or ADU construction visible from the street. The HDC reviews proposals for compatibility with the district's historic character. Applications are reviewed at monthly HDC meetings. Contact the Detroit Planning and Development Department at (313) 224-6380.
What permits does Detroit require for a home addition?
A building permit from the Detroit BSEED is required for all structural additions. You'll need architectural drawings, property ownership verification, and compliance with zoning setbacks. Permit fees are based on construction value. Detroit's permit office is at the Coleman A. Young Municipal Center. Applications can be initiated online through the BSEED portal. Expect 4-8 weeks for plan review.
Source: Detroit Buildings, Safety Engineering and Environmental Department (BSEED) — Building Regulations. Last verified April 6, 2026. View source