Building an ADU in Atlanta
City code and Georgia law · Last reviewed October 9, 2026
Atlanta's zoning ordinance allows a detached accessory dwelling unit (ADU) of 750 square feet or less in the R-4, R-4A and R-5 residential districts, as long as the lot has no more than two homes in total. No parking is required for the ADU, and accessory buildings in residential districts can be up to 20 feet tall. You apply for permits through the city's online permitting portal. [1][2][3][4][5]
| Where ADUs are allowed | R-4, R-4A and R-5 districts, plus several SPI and historic districts with their own rules; not R-1 through R-3 or R-4B [1][2][3][6][7] |
|---|---|
| How many homes per lot | No more than two dwelling units in total, including the ADU [1][2][3] |
| Type | Detached only; the definition covers a detached dwelling unit [4][7] |
| Max size | 750 sq ft of floor area [4] |
| Height | 20 ft for accessory buildings in R-1 through R-5 [4][5] |
| Accessory building limits | Can't cover more than 25% of the rear yard or exceed 30% of the main home's floor area [5] |
| Setbacks | R-5: 4 ft side and rear for ADUs. R-4 and R-4A: beside or behind the house, within the buildable area [1][2][3] |
| Parking | No parking required for ADUs in R-4, R-4A and R-5 [1][2][3] |
| Short-term rental | An ADU may be a short-term rental only if the owner lives on site; a city license is required [4][11] |
| Lot splits | In R-5, an ADU may not be subdivided from its lot [3] |
| State ADU law | None; HB 1166 (2026) did not pass [12] |
On this page
What you can build here
Atlanta's zoning ordinance defines an accessory dwelling as "a detached dwelling unit meeting the height requirement of section 16-28.004 and having a floor area of 750 square feet or less on the same lot as a primary dwelling." It has its own kitchen.
ADUs are listed as a permitted accessory use in the R-4, R-4A and R-5 districts "where the total number of dwelling units on any parcel, including the accessory dwelling unit, does not exceed two." So in R-5 you can't add an ADU to a duplex. The Department of City Planning also says detached ADUs are allowed in several special public interest (SPI) and historic districts, which have their own rules.
The R-1 through R-3 districts and R-4B do not list ADUs as a permitted use. They allow guest houses, but a guest house can't have its own kitchen.
An accessory building can't be built before construction of the main house has begun, and can't be used until the main house is finished and in use. [1][2][3][4][6][7]
Size, height and setbacks
Size. An ADU can have up to 750 square feet of floor area. Separately, accessory buildings in R-1 through R-5 "shall not cover more than 25 percent of the area of the rear yard, and shall not contain a total floor area greater than 30 percent of the main structure," counting all gross floor area whether or not it is heated. Ask the Office of Zoning and Development how these limits apply together on your lot.
Height. Accessory buildings in R-1 through R-5 can't exceed 20 feet.
Setbacks. In R-5, the minimum side and rear yard for an ADU is 4 feet. In R-4 and R-4A, accessory structures must be placed to the side or rear of the main house "within the buildable area of the lot" and can't project beyond the front of the house. The R-4 district's required yards are 35 feet in front, 7 feet on each side and 15 feet in the rear.
Floor area. In R-5, the floor area limits for a single-family home include the ADU; on a lot that meets the minimum lot size, the maximum floor area ratio is 0.50.
A Department of City Planning proposal would allow attached ADUs, raise the size limit to 1,000 square feet and the height to 24 feet, and add R-4B. As of the code current through August 26, 2026, those changes are not in the ordinance. [1][3][4][5][7][8]
Parking
The R-4, R-4A and R-5 district rules each say: "Accessory dwelling units: No parking required." [1][2][3]
Fees and timeline
The city doesn't publish a separate fee schedule or review time for ADUs. You pay fees in the ACA permitting portal by searching for your record and opening its Payments tab. The portal accepts American Express, Discover, MasterCard and Visa.
After you submit, staff check the application for completeness and email you about next steps. For questions, call general permitting at 404-330-6150. See our ADU cost guide and ADU permit process guide. [9][10]
Garage conversions
Atlanta's ADU definition covers a detached unit, so a detached garage conversion can qualify, but a basement or attached garage conversion isn't an ADU under the current code. The Department of City Planning notes that "currently ADU allowance is limited to detached structures." A converted garage must meet the same 750-square-foot, 20-foot height and accessory building limits. Confirm with the Office of Zoning and Development before you design. See our garage conversion guide. [4][5][7]
Renting it out
Atlanta's zoning ordinance says an ADU "may be used as short-term rental provided that the primary property owner resides onsite." A short-term rental is a stay of 30 consecutive days or less.
Anyone renting a dwelling short term needs a short-term rental license from the Department of City Planning first. An owner or long-term tenant can get a license for their primary residence and one additional unit. You can apply for the license in the city's online permitting portal.
In R-5, an ADU may not be subdivided from its lot. [3][4][9][11]
State law and other options
Georgia has no statewide ADU law. In 2026, House Bill 1166 would have let homeowners add one home of 400 square feet or less on a homesteaded lot without a zoning decision, but it never got a final Senate vote. See our Georgia ADU law page.
For financing ideas, see our ADU financing guide. For options like small backyard homes, see our backyard tiny house guide. [12][13]
Permit steps in Atlanta
Confirm your zoning district
Check whether your lot is zoned R-4, R-4A or R-5, or is in an SPI or historic district with its own ADU rules, and read the district chapter in the Atlanta zoning ordinance. [1][7]
Design to the zoning limits
Keep the ADU detached, at or under 750 square feet and 20 feet tall, and within your district's setback, floor area and lot coverage limits. [3][4][5]
Get historic or special district approvals
Historic and SPI districts have their own ADU rules. The online permitting portal lists Historic Preservation Studio approval among the supplemental documents you may need to upload with your application. [7][9]
Apply online
Log in to the ACA permitting portal, select Submit an Application, choose the single- and two-family category and enter your address, contacts and licensed professional. Upload the application and plans as unlocked PDFs drawn to scale. [9]
Pay fees and receive the permit
Once staff accept the submittal, you'll get an email with next steps. Pay fees in the portal under the record's Payments tab. Contractors must show the physical state-issued license card before the permit is issued. [9]
Build and pass inspections
Request inspections through the Department of City Planning; some inspection types can be done virtually. [10]
Who to call
-
Department of City Planning, permitting
General permitting questions; walk-in transactions 8:15 a.m. to 3:30 p.m.
Atlanta City Hall, 55 Trinity Ave SW, Atlanta, GA 30303
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Residential additions and alterations under 1,500 sq ft
Permit line for smaller residential projects
-
Express permit service
Questions people ask
Where can I build an ADU in Atlanta?
In the R-4, R-4A and R-5 zoning districts, and in several SPI and historic districts with their own rules, as long as the lot has no more than two homes in total including the ADU. R-1 through R-3 and R-4B don't list ADUs. [1][2][3][6][7]
How big can an ADU be in Atlanta?
Up to 750 square feet of floor area and 20 feet tall. Accessory buildings also can't exceed 30% of the main home's floor area or cover more than 25% of the rear yard, so confirm your limit with the city. [4][5]
Can I build an attached ADU or basement apartment in Atlanta?
Not as an ADU under the current code, which defines an ADU as a detached unit. A city proposal to allow attached ADUs has not been added to the ordinance. [4][7][8]
Sources (13)
- Atlanta Code, Part 16 Zoning, Chapter 6. R-4 Single-Family Residential District Regulations, City of Atlanta (Municode). Accessed October 9, 2026.
- Atlanta Code, Part 16 Zoning, Chapter 6A. R-4A Single-Family Residential District Regulations, City of Atlanta (Municode). Accessed October 9, 2026.
- Atlanta Code, Part 16 Zoning, Chapter 7. R-5 Two-Family Residential District Regulations, City of Atlanta (Municode). Accessed October 9, 2026.
- Atlanta Code, Part 16 Zoning, Chapter 29. Definitions (Sec. 16-29.001), City of Atlanta (Municode). Accessed October 9, 2026.
- Atlanta Code, Part 16 Zoning, Chapter 28. General and Supplementary Regulations (Sec. 16-28.004), City of Atlanta (Municode). Accessed October 9, 2026.
- Atlanta Code, Part 16 Zoning, Chapter 6B. R-4B Single-Family Residential District Regulations, City of Atlanta (Municode). Accessed October 9, 2026.
- Create More Flexible ADU Options, City of Atlanta Department of City Planning. Accessed October 9, 2026.
- Atlanta Code of Ordinances, Supplement 107 (codified through Ordinance No. 2026-31, enacted August 26, 2026), City of Atlanta (Municode). Accessed October 9, 2026.
- Online Permitting, City of Atlanta Department of City Planning. Accessed October 9, 2026.
- Department of City Planning, City of Atlanta. Accessed October 9, 2026.
- Atlanta Code, Part 20. Short Term Rentals (Secs. 20-1001 to 20-1004), City of Atlanta (Municode). Accessed October 9, 2026.
- HB 1166, 2025-2026 Regular Session (status history), Georgia General Assembly. Accessed October 9, 2026.
- HB 1166, House Committee on Governmental Affairs substitute (LC 47 4123S), Georgia General Assembly. Accessed October 9, 2026.