ADU types · Atlanta, GA

ADU types we design, permit and build around Atlanta.

Four ways to add a second dwelling, plus the design and permit work behind every one of them. Which one fits depends on your zoning district first and your yard second.

Detached ADUA new freestanding unit. The type the City of Atlanta's code allows today in R-4, R-4A and R-5.Detached ADUs Garage conversionReuses a sound detached garage. Insulation, plumbing and new openings do most of the work.Garage conversions Attached ADUA unit that shares a wall or floor with the house, such as a lower-level suite.Attached ADUs Garage apartmentA living unit above parking. Height caps decide whether it fits.Garage apartments

ADU design and permitsZoning research, drawings, structural engineering, the permit application and responses to reviewer comments. Part of every build, or available on its own.Design and permits

How do the types compare in the City of Atlanta?

A summary of what City Planning publishes about current ADU rules, as of October 2026. Nearby cities have their own codes; see each area page.

Type	City of Atlanta status	Key limit	Worth a look when
Detached ADU	Allowed by right in R-4, R-4A and R-5, and in some special public interest and historic districts	750 sq ft and 20 ft tall	The back yard is deep enough and the lot is in an eligible district
Garage conversion	A detached garage turned into a unit is treated as a detached ADU	Same district and size limits	The garage already sits behind the house and is structurally sound
Attached ADU	Not allowed under current rules; a city proposal would change that	Proposal: up to 50% of the house or 1,000 sq ft	You are in Decatur or Sandy Springs, or can wait for Atlanta's rules to change
Garage apartment	Possible as a detached ADU, but the 20 ft height cap makes two stories hard	Proposal would raise height to 24 ft	The site allows a low roof pitch or the city adopts the higher limit

Which type usually costs least?

Converting space that already has a roof and walls usually costs less than building from the slab up. That said, a garage with a cracked slab or rotten framing can erase most of the saving. Published 2026 figures are in the Atlanta ADU cost guide.

Find out what your lot allows.

Give us the property address and the kind of unit you have in mind. We read the zoning for that parcel, flag anything that could stop the project, and reply before any design work starts. Serving Atlanta, Decatur, Sandy Springs, Marietta and East Point.