Detroit's Accessory Structures: The Rules That Matter

Every city handles accessory structures a little differently. In Detroit, Michigan, there are 9 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Tiny Homes

Detroit has no separate 'tiny home' use category in Chapter 50; tiny dwellings are regulated either as standard single-family detached dwellings (the model used by Cass Community Social Services on Elmhurst, Monterey, and Richton) or as accessory dwelling units under the October 2025 'Let's Build More Housing' amendment. All tiny homes must be on permanent foundations and comply with the Michigan Residential Code; tiny houses on wheels are not recognized as permanent dwellings by Chapter 50.

Key details: Tiny-home Use Class: None (uses standard SFR or ADU). Permanent SFR Path: Underlying R-district rules. ADU Path (since 10-16-25): Sited in R2-R6. Foundation: Permanent required. Building Code: Michigan Residential Code.

Placing a tiny house on wheels on a Detroit residential lot for full-time occupancy, or constructing a foundation-built tiny home without BSEED building and trade permits and without compliance with the Michigan Residential Code, is a zoning and building-code violation enforceable by BSEED. Violations may result in stop-work orders, citations, removal orders, or denial of certificate-of-occupancy. Use of accessory structures (sheds, detached garages) as full-time dwellings without ADU approval is treated as an unauthorized dwelling unit and subjects the owner to property-maintenance and zoning enforcement.

This is not one of those rules that cities tend to ignore. Detroit actively enforces its tiny homes requirements.

Carport Rules

Detroit regulates carports as accessory buildings/structures under Chapter 50 (Zoning Ordinance), placing them in the rear yard subject to the city's accessory-structure setbacks and a one-story, fifteen-foot height cap typical of detached accessories in R1/R2 districts. A BSEED building permit is required for carport construction, with the Michigan Residential Code applied to single- and two-family lots.

Key details: Zoning Code: Chapter 50. Classification: Accessory building/structure. Max Height (R1/R2): 15 ft, one story. Height vs. Principal: Cannot exceed principal. Location: Rear setback area.

Building a carport without a BSEED permit, exceeding fifteen (15) feet in height, locating it outside the rear setback area or in violation of side-yard setbacks, or building it taller than the principal structure are zoning violations that may result in stop-work orders, citations, or required removal/modification. Permit-less carports added to corner lots are flagged in Detroit because corner-lot setback rules apply to two street-facing yards. Owners can apply to the Detroit Board of Zoning Appeals (BZA) for a variance where strict compliance is impractical.

ADU Rules

Under Detroit's current Chapter 50 Zoning Ordinance, accessory dwelling units are not permitted by right in R1 or R2 districts; only pre-1940 carriage-house dwellings are recognized, and a 2025 'Let's Build More Housing' text amendment expanding ADUs is still working through City Council.

Key details: ADU in R1: Not permitted (pre-1940 carriage house only). ADU in R2: Not by-right (proposed for 2025/26 amendment). Code Authority: Detroit Ch. 50 Zoning, Art. VIII. Pending Reform: Let's Build More Housing text amendment.

Constructing or occupying an unpermitted ADU is a zoning violation enforced by BSEED with stop-work orders, civil fines through the Department of Appeals and Hearings, and possible vacation of the structure.

Compared to other cities, Detroit takes a harder line on adu rules. The enforcement and penalty structure reflects that.

Shed Rules

Detroit Chapter 50, Article XIII limits detached accessory buildings in R1 and R2 to 15 feet in height and one story, requires 10 feet of separation from the principal dwelling, and prohibits occupying more than 50% of the required rear setback area.

Key details: Max Height (R1/R2): 15 feet, one story. Separation from House: 10 feet minimum. Rear-Setback Coverage: Max 50%. Corner-Lot Setback: 10 ft from side street line. Code Section: Ch. 50, Art. XIII (formerly 61-13-128 to 130).

Building or maintaining a shed that exceeds height, coverage, or setback limits is a zoning violation enforced by BSEED; typical remedies include stop-work orders, removal orders, and civil fines via the Department of Appeals and Hearings.

Garage Conversions

Converting a Detroit detached garage into living space generally creates a second dwelling unit that is not permitted in R1 districts, and requires a BSEED building permit plus zoning approval; today most conversions are denied because Chapter 50 does not allow new detached ADUs in R1/R2.

Key details: Habitable Conversion in R1: Not permitted. Storage / Workshop Use: Allowed within Art. XIII limits. Permits Required: BSEED building + zoning review. Max Accessory Height: 15 ft / 1 story (Art. XIII).

An unpermitted garage conversion is both a zoning violation (illegal dwelling unit) and a building-code violation; BSEED can issue stop-work orders, blight tickets, and orders to restore the structure to non-habitable accessory use through the Department of Appeals and Hearings.

This is not one of those rules that cities tend to ignore. Detroit actively enforces its garage conversions requirements.

ADU Impact Fees

Detroit does not charge true 'impact fees' on ADUs because Michigan municipalities lack general statutory authority to impose impact fees on residential development. Costs for an ADU are limited to BSEED building permit fees, plan review fees, and DWSD water/sewer connection charges based on actual service draw.

Key details: Impact Fees: None (Bolt v. Lansing). Building Permit: Per BSEED fee schedule. Water/Sewer: DWSD tap fee only. School Fees: Not authorized. Property Tax: SEV reassessment.

Building without a permit avoids fees but exposes the property to BSEED stop-work orders, double permit fees on after-the-fact applications, and blight ticket penalties. DWSD may disconnect service for unauthorized connections.

If you are coming from a city with tighter rules, you will find Detroit gives residents more flexibility on adu impact fees.

ADU Owner Occupancy

Detroit's Chapter 50 Zoning Ordinance does not impose a citywide owner-occupancy requirement on the limited ADU category (pre-1940 carriage houses). However, if both the primary dwelling and the ADU are rented to non-owners, both units must be registered under Detroit Code Chapter 8 Article XV (the Rental Ordinance) and pass an inspection-based Certificate of Compliance.

Key details: Zoning Owner-Occupancy: Not required by Ch. 50. Rental Registration: Required if rented (Ch. 8). Certificate of Compliance: Every 3 years. Historic District: Separate COA required. Department: BSEED rental compliance.

Renting an unregistered ADU is a Chapter 8 violation enforced through blight tickets and rental registration penalties. Loss of Certificate of Compliance bars future rental until inspection and re-registration. Renting an unpermitted dwelling unit is a separate Chapter 50 zoning violation.

ADU Rental Restrictions

Detroit does not separately ban short-term rentals of ADUs in zoning, but any ADU rented to a non-owner is subject to Detroit Code Chapter 8 Article XV. ADUs used for stays under 30 days must also comply with the City's Hotel-Motel Tax (Detroit Code Ch. 18) and Michigan's 6% Use Tax on accommodations.

Key details: Rental Registration: Required (Ch. 8 Art. XV). STR Permit: No separate citywide license. Hotel-Motel Tax: 2% (Ch. 18). Use Tax: 6% Michigan. Stays <30 Days: Treated as transient.

Unregistered ADU rental: blight ticket and order to register; loss of right to evict for nonpayment until compliance under MCL 125.530. Operating a transient accommodation without collecting Hotel-Motel Tax: tax delinquency and penalties under Ch. 18. HDC violations in historic districts: separate enforcement.

ADU Permits

Detroit has historically restricted ADUs under the 2019 Zoning Ordinance (Chapter 50 of the Detroit City Code). Until the October 2025 Let's Build More Housing zoning amendments take full effect, accessory dwelling units are only permitted in pre-1940 carriage houses and similar legally-existing accessory structures, with no by-right new construction of detached ADUs in most R1/R2 zones.

Key details: Zoning Code: Detroit Code Ch. 50 (2019 Ord.). Current Path: Pre-1940 carriage houses. 2025 Reform: Let's Build More Housing (pending). Permit Agency: BSEED. CO Required: Yes - change of use.

Creating an unpermitted dwelling unit is a Chapter 50 zoning violation and a Michigan Residential Code violation. BSEED may issue stop-work orders, blight tickets, and ordered abatement; unpermitted units cannot be legally rented and may be excluded from rental registration under Chapter 8 Article XV.

This is one of the stricter rules in Detroit's municipal code. If you are unsure whether your situation complies, it is worth checking with the city before proceeding.

The Bottom Line

Detroit is tougher than many cities when it comes to accessory structures. Out of the 9 rules covered here, 4 are rated strict. If you are a homeowner, renter, or business owner in Detroit, take the time to understand these requirements before they become a problem. Most violations come with fines, and some repeat violations can escalate.

These rules come from Detroit's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.