Atlanta, GA Accessory Structures: Garage Conversions (2026)

Under Atlanta's Part 16 zoning code (Part III, Code of Ordinances - Land Development Code), accessory dwelling units are currently restricted to detached structures in R-4, R-4A, and R-5 districts and select SPI/historic overlays - attached configurations such as basement apartments and garage-apartment conversions are not permitted as separate dwelling units under existing rules. A 2024-2025 Department of City Planning proposal ("Allow attached ADUs, for sale option and expand citywide") would change this by allowing attached ADUs up to 50% of the principal dwelling or 1,000 sq ft, raising detached height to 24 feet, and adding R-4B, but as of the current code attached/garage-conversion ADUs remain prohibited. Converting a garage to additional living space (added bedroom, family room, etc.) for the existing single household is allowed but requires a building permit from the City of Atlanta Office of Buildings, with plans showing egress, smoke and CO alarms, insulation, and a permanent heating/cooling source, and separate trade permits for any plumbing, electrical, or HVAC work. Atlanta's Office of Buildings enforces the Georgia State Minimum Standard One and Two Family Dwelling Code (2018 IRC with Georgia amendments) for residential conversions; effective January 1, 2026, permit submittals will be reviewed under the 2024 IRC with Georgia amendments. Conversions in historic districts or NPU overlay areas may require additional design review.