ADU Rules in the City of Atlanta
Verified against City of Atlanta zoning provisions and Sec. 16-06.004 · August 2026
Building elsewhere in Metro Atlanta? See our guides to Decatur and DeKalb County ADU rules.
Yes, you can build an ADU in the City of Atlanta. But the rules are narrower than most homeowners expect, and they are actively being rewritten. Here is what applies today, and what may change.
Can I build one on my lot?
Detached accessory dwelling units are permitted by right, meaning no variance is needed, in the R-4, R-4A and R-5 zoning districts, along with several Special Public Interest districts and historic districts. Together those cover a majority of Atlanta's residential land.
They are not currently permitted in R-1, R-2 or R-3, the larger-lot districts covering roughly 17% of the city's one and two-family lots.
Sec. 16-06.004 permits accessory dwelling units as an accessory use provided the total number of dwelling units on the parcel, including the ADU, does not exceed two. In practice that means a duplex lot cannot add a third unit.
How big can it be?
750 square feet maximum.
And an important detail most homeowners miss: garage square footage currently counts toward that allowance. If you build a garage with living space above, the garage floor consumes part of the 750.
How tall, and where on the lot?
Height is capped at 20 feet. Rear and side setbacks are 4 feet in R-5, and 15 feet in R-4 and R-4A.
The 20-foot limit is the constraint that shapes most Atlanta projects. A true two-storey structure with habitable space above a garage is difficult to fit beneath it, which is why Atlanta ADUs tend to be smaller single-level units or compact studios above shallow garage footprints.
Do I have to live on the property?
No. Atlanta does not impose an owner-occupancy requirement. You may rent both the main house and the ADU.
This is a meaningful difference from Decatur and DeKalb County, both of which require the owner to live in one of the units. It makes the City of Atlanta the more flexible jurisdiction for an income-focused project.
What's changing?
Atlanta's zoning rewrite, known as ATL Zoning 2.0, includes substantial ADU reform. As of mid-2026 it has been submitted for City Council review and has not been adopted. The proposals include:
Raising the detached ADU cap from 750 to 1,000 square feet
Raising the height limit from 20 to 24 feet, specifically to allow a second floor and units over garages
Allowing attached ADUs, including basement apartments and garage conversions, for the first time
Adding ADU allowance to the R-4B district
Reducing rear and side setbacks to 4 feet in R-4, R-4A and R-4B
Counting only conditioned space toward the square footage allowance, so garage area would no longer reduce it
Permitting three total units in R-5, such as a duplex plus an ADU
A zero-lot-line configuration allowing ADUs to be sold separately
If adopted, the combination of 1,000 square feet, 24 feet of height, and garage space no longer counting would substantially change what is buildable on an Atlanta lot. We track this because it changes what we can design.
What else will hold up your permit?
Zoning is only the first gate. Depending on your property you may also need historic district review, arborist approval, HOA or architectural approval, or environmental and septic sign-off. Any one of them can add weeks.
Frequently asked questions
Can I build an attached ADU or convert my basement in Atlanta?
Not currently. Atlanta permits detached ADUs only. Attached ADUs are part of the Zoning 2.0 proposal under council review but have not been adopted.
How big can an ADU be in Atlanta?
750 square feet, and garage area counts toward that total under current rules.
How tall can an ADU be in Atlanta?
Twenty feet under current rules. The Zoning 2.0 proposal would raise this to 24 feet to allow a second floor or a unit above a garage.
Do I have to live on the property to rent out an ADU in Atlanta?
No. Atlanta does not require owner-occupancy, so both the main house and the ADU can be rented.
Can I have two ADUs in Atlanta?
No. The total number of dwelling units on the parcel, including the ADU, cannot exceed two.
What zoning districts allow ADUs in Atlanta?
R-4, R-4A and R-5 by right, plus certain SPI and historic districts. ADUs are not currently permitted in R-1, R-2 or R-3.
Thinking about an ADU in the City of Atlanta?
We'll confirm your zoning district, what's buildable under the current cap, and whether waiting on Zoning 2.0 changes your options. Call 404-509-5526.
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