Accessory Structures in Mobile, AL (2026)
9 verified accessory structures rules for Mobile, Alabama, sourced directly from the municipal code and official government pages.
Verified from official government sources
ADU Rules
Mobile allows one ADU per single-family lot under the unified development code. Size is generally limited to 1,000–1,200 square feet or a percentage of the primary dwelling. ADUs must meet building code standards.
Mobile Accessory Dwelling Unit (ADU) Rules
Some RestrictionsADU Permits
Mobile authorizes accessory dwelling units (ADUs) under the Mobile Unified Development Code (Code of Ordinances Chapter 64), adopted June 7, 2022. ADUs are allowed in residential districts on lots permitting a single dwelling, must sit on a permanent foundation, and require a building permit through Build Mobile (Permitting & Inspections Division). Alabama is a Dillon Rule state with no statewide ADU preemption. Construction follows the Alabama-adopted International Residential Code with Gulf Coast hurricane wind-load amendments.
Mobile Accessory Dwelling Unit Permits (UDC Ch. 64)
Some RestrictionsADU Impact Fees
Mobile does not impose a general residential impact fee on accessory dwelling units. Alabama law does not broadly authorize municipal residential impact fees outside specific statutory grants. ADU costs include standard building, electrical, plumbing, and mechanical permit fees through Build Mobile plus tap/connection fees from the Mobile Area Water and Sewer System (MAWSS) and Alabama Power if a new utility service is required.
Mobile ADU Impact Fees (No General Residential Impact Fee)
Few RestrictionsADU Owner Occupancy
The Mobile Unified Development Code (Chapter 64) treats ADUs as accessory uses subordinate to the principal single-family dwelling and prohibits separate sale of the ADU from the main dwelling. The practical effect is an owner-presence expectation: the principal dwelling must remain occupied as a single-family residence, with the ADU used as accessory space. Alabama has not preempted local ADU rules. Variances or zoning changes are pursued through the Mobile Board of Zoning Adjustment or Planning Commission.
Mobile ADU Owner-Occupancy Practice
Some RestrictionsADU Rental Restrictions
The Mobile Unified Development Code (Chapter 64) historically prohibits use of an accessory dwelling unit as a short-term rental, and ADUs cannot be sold separately from the principal dwelling. Long-term rental of an ADU as a fully separate tenancy generally requires zoning that permits a two-family dwelling. Short-term rental operations citywide require a city business license under Code Chapter 34 and collection of city, county, and state lodgings taxes. Alabama has not preempted local STR rules.
Mobile ADU Rental Restrictions and STR Rules
Heavy RestrictionsShed Rules
Mobile regulates sheds through zoning setbacks and size limits. Small sheds under 120 square feet typically do not require a building permit but must meet setback requirements.
Mobile Shed & Outbuilding Rules
Some RestrictionsGarage Conversions
Mobile allows garage conversions to living space with a building permit. The converted space must meet residential building code and parking requirements must still be met.
Mobile Garage Conversion Rules
Some RestrictionsCarport Rules
Carports in Mobile are accessory structures regulated by the Mobile Unified Development Code (Chapter 64, Zoning) and require a building permit from Build Mobile. Construction must meet Alabama-adopted IRC wind-load requirements for the Gulf Coast hurricane zone, plus the underlying district setbacks, height, and lot-coverage limits.
Carport Rules in Mobile
Some RestrictionsTiny Homes
Mobile's Unified Development Code (Chapter 64, June 2022) authorizes Accessory Dwelling Units in residential districts on lots permitting a single dwelling. ADUs must be smaller than the primary residence, sit on a permanent foundation, and obtain a building permit. Alabama has no statewide tiny-home preemption; the state-adopted IRC governs minimum dwelling standards.
Tiny Home Rules in Mobile
Some RestrictionsLooking for Mobile County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Mobile city rules.
Accessory Structures in Mobile County →