Inside the City of Atlanta, as of October 2026, detached ADUs are allowed by right in the R-4, R-4A and R-5 districts and in some special public interest and historic districts, up to 750 sq ft and 20 feet tall. Attached ADUs are not allowed yet. Decatur, Sandy Springs, Marietta and East Point each write their own rules.
What should City of Atlanta homeowners check first?
- Your zoning district. R-4, R-4A and R-5 are eligible. The larger-lot R-1, R-2 and R-3 districts are not on City Planning's list.
- City limits. Many addresses with an Atlanta mailing address are actually in unincorporated DeKalb or Fulton County, or another city, and follow different rules.
- Historic or SPI districts. Some allow ADUs, and design review can apply.
- Trees. The city's tree protection ordinance can shape where a unit can go.
- Pending changes. A city ADU proposal and a draft zoning rewrite are both in progress; neither was adopted as of October 2026.
What is changing in Atlanta's ADU rules?
City Planning has published a proposal to allow attached ADUs, raise the detached cap to 1,000 sq ft and 24 feet, add R-4B, set 4-foot side and rear setbacks in the R-4 family of districts, and allow a for-sale ADU through a zero-lot-line arrangement. Separately, the draft rewrite of the city's 1982 zoning code was held by the council's zoning committee in September 2026 for revisions. We track both and design to whatever is in force when you apply.