Atlanta, GA Accessory Structures: ADU Permits (2026)

Atlanta legalized accessory dwelling units citywide in 2017 with Ordinance 17-O-1605, which amended Chapter 16 of the City Code to allow detached ADUs (carriage houses), attached ADUs, and interior ADUs in single-family residential districts including R-4, R-4A, R-5, and select multi-family districts. Standards under §16-29 (and the specific district sections such as §16-06.010) include: maximum floor area of 750 sq ft for detached ADUs or 50% of the principal dwelling for attached ADUs; maximum height of 25 ft for detached ADUs; minimum setback of 7 ft from rear and side property lines; minimum one off-street parking space (waivable in transit-served areas); and the lot must contain only one ADU. Permitting flows through the Atlanta Department of City Planning's Office of Zoning and Development for zoning compliance, then to the Office of Buildings for a building permit under the Georgia State Minimum Standard Building Codes (Atlanta enforces the 2018 International Residential Code with Georgia amendments). The recently completed 2023-2024 Zoning Diagnostic recommends expansion of ADU permissions, but the existing 2017 framework remains in effect.