Accessory Structures in Ann Arbor, MI (2026)
9 verified accessory structures rules for Ann Arbor, Michigan, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Michigan has no statewide ADU mandate. Ann Arbor ADU policies depend on local zoning. Some Michigan cities have adopted ADU-friendly ordinances.
Ann Arbor ADU (Accessory Dwelling Unit) Rules
Some RestrictionsADU Permits
Ann Arbor is among Michigan's earliest by-right ADU cities. The Unified Development Code (UDC) Section 5.16.4 (formerly Chapter 55 Zoning, amended by Ordinance 16-13 in 2016) permits accessory dwelling units on any lot containing a one-family or two-family dwelling. Permits issue through the Building Department (a2gov.org/BuildingPermits) under the Michigan Residential Code.
Ann Arbor ADU Permits (UDC By-Right Since 2016)
Few RestrictionsADU Impact Fees
Ann Arbor cannot impose true development impact fees on ADUs because Michigan law forbids them. The Michigan Supreme Court in Bolt v. City of Lansing, 459 Mich 152 (1998), held municipalities lack authority to charge impact fees without specific statutory authorization. ADU costs are limited to Building Department permit fees and water/sewer connection charges.
Ann Arbor ADU Impact Fees (None - Bolt v. Lansing Bars Them)
Few RestrictionsADU Owner Occupancy
Ann Arbor requires owner-occupancy of an ADU property. UDC Section 5.16.4 mandates that the property owner reside in either the principal dwelling or the ADU as their primary residence. Only one of the two units may be rented to a non-owner. Both units must be registered under Ann Arbor Housing Code Chapter 105 if rented.
Ann Arbor ADU Owner-Occupancy (Required Under UDC 5.16.4)
Some RestrictionsADU Rental Restrictions
Ann Arbor ADUs may be rented long-term only by the unit not occupied by the owner, under UDC 5.16.4 and Housing Code Chapter 105. The 2024 short-term rental ordinance (Chapter 117) bans non-owner-occupied whole-house STRs in single-family residential zones, limiting STR use of an ADU to homestays where the owner remains on the property.
Ann Arbor ADU Rental Restrictions (Chapter 105 + 2024 STR Ordinance)
Heavy RestrictionsShed Rules
Ann Arbor allows small sheds without permits (typically under 200 sq ft per Michigan Building Code). Larger structures require permits and must meet setbacks.
Ann Arbor Shed & Outbuilding Rules
Few RestrictionsGarage Conversions
Ann Arbor may allow garage conversions to living space with building permits. No state law facilitating conversions - local zoning and parking requirements apply.
Ann Arbor Garage Conversion Rules
Some RestrictionsCarport Rules
Ann Arbor requires permits for carport construction. Setback requirements, height limits, and lot coverage maximums apply.
Ann Arbor Carport Construction Rules
Some RestrictionsTiny Homes
Ann Arbor regulates tiny homes differently based on whether they are on a permanent foundation or on wheels. Zoning and minimum square footage requirements apply.
Ann Arbor Tiny Home & Small Dwelling Rules
Some RestrictionsLooking for Washtenaw County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Ann Arbor city rules.
Accessory Structures in Washtenaw County →