In plain words
Alabama has no state law about ADUs. An ADU, or accessory dwelling unit, is a small second home on the same lot as a house. It might be a backyard cottage, a garage apartment, or a suite inside the house. In Alabama, each city decides through its zoning. Zoning is the local rulebook for what can be built where. Many rural areas have no zoning at all. Some counties zone only certain areas. In Baldwin County, a rural area is zoned only after its residents vote for it. The two largest cities show how limited the options can be. Huntsville does not list ADUs in its zoning code. It lets a family add a second kitchen only inside the main house, for relatives or guests who do not pay rent. The owner must live there. That is called an owner-occupancy rule. Birmingham does not allow ADUs in every neighborhood today. In 2026 it began asking residents whether to write new ADU rules. State lawmakers did not file any ADU bills from 2023 through 2026, so no state change is in the works. Even where zoning does not block an ADU, other rules still apply. The county health department must approve any septic system. Building codes and HOA rules may also limit what you can do. Before you plan, call your city or county. You may be able to build only if local rules and your property allow it.
The rules at a glance
| State ADU law | No. Each city, town or county decides. |
|---|---|
| Owner living on site | Towns may require the owner to live on the property. |
| Parking | State law doesn’t set this. Each city sets its own parking rules. |
| Size | State law doesn’t set this. Each city sets its own limits, if it allows ADUs at all. |
| Lot size and setbacks | State law doesn’t set this. Cities set lot size and setback rules in their zoning codes under Ala. Code §11-52-70 and following. |
| Fees | State law doesn’t set this. Permit, utility and sewer fees are set locally. |
| Short-term rentals | State law doesn’t set this. Short-term rentals are regulated, if at all, by cities and some counties. |
What to do next
- Find out whether your property is inside city limits; if it is, the city's zoning code decides whether an ADU is allowed.
- If you are outside city limits, ask the county whether your area is zoned; in many places it is not, but building permits may still be required.
- Contact the county health department early if you use a septic system or well, since it must approve service for any added dwelling.
- Read your deed and any HOA covenants; private restrictions can ban a second unit even where zoning is silent.
- Ask the city or county about owner-occupancy, size, parking and rental limits before you design.
- Get any required zoning approval and building permits before construction starts.
What your town still decides
Alabama has no law about ADUs. Cities zone under the state's municipal zoning law (Ala. Code Title 11, Chapter 52, Article 4, starting at §11-52-70), and each city decides whether a second home on a lot is allowed. Outside city limits the picture is patchy: some unincorporated areas have county zoning and many do not. In Baldwin County, for example, a rural planning district comes under county zoning only after residents petition and vote for it. Where there is no zoning, building codes and county health department septic and well rules still decide whether a second unit can be built. A scan of the titles and subjects of all 3,757 bills filed in the 2023-2026 regular and special sessions found no bill about accessory dwelling units. Private deed restrictions and HOA rules can also ban a second unit.
Examples of local rules
- Huntsville: The city zoning ordinance (as of April 1, 2026) has no ADU category. In its Residence 1, 1-A, 1-B and 1-C districts a homeowner may add a second kitchen only inside the main house, only for family members or non-paying guests, and only if the owner lives there. No kitchen is allowed in a detached accessory building, and separate meters, a second mailbox or a second address are not allowed. A house with a second kitchen may not be rented out unless the second kitchen is removed first. Source
- Birmingham: ADUs exist in some older neighborhoods but are not allowed in all residential districts under current zoning. In May 2026 the city began exploring an ADU ordinance and held town halls across the city from June 9 to 30, 2026. As of the city's page, no decisions had been made and no ordinance text had been released. Source
- Baldwin County (unincorporated areas): County zoning applies only in planning districts that voted it in. A district is added after 10% of its registered voters sign a petition and a majority approve it in an election. In districts that have not voted it in, the county zoning ordinance does not apply. Source
Sources
- Code of Alabama Title 11, Chapter 52, Article 4 (Zoning), §11-52-70 and following · official source · checked 2026-10-03
- Alabama Legislature (ALISON) bill database: titles and subjects of all 3,757 bills in the 2023-2026 regular and special sessions, plus full-text searches for 'accessory dwelling', 'accessory apartment', 'tiny home', 'granny flat' and 'secondary dwelling' (no ADU bills found) · official source · checked 2026-10-03
- City of Huntsville Zoning Ordinance as of April 1, 2026 (Sec. 10.6 Second Kitchens) · official source · checked 2026-10-03
- City of Birmingham, Accessory Dwelling Units (ADU) community conversation page · official source · checked 2026-10-03
- City of Birmingham news release, community conversation on ADUs (May 11, 2026) · official source · checked 2026-10-03
- Baldwin County Planning and Zoning, Zoning in Baldwin · official source · checked 2026-10-03
This is general information, not legal advice. Your town, village, city or county decides what can be built on your property. If something here looks out of date, email the team.