Compare ADU zoning rules across 3 Alabama cities. Average ADU score: 3.7/10.
| City | Max Size | Setbacks | Permit Fees | Build Cost | 1BR Rent | Score |
|---|---|---|---|---|---|---|
| Birmingham | Not established — no ADU ordinance exists; confirm with Birmingham Planning Division | Underlying district accessory-structure setbacks apply; ADU-specific standards do not exist yet — confirm with Birmingham Planning Division | Confirm with Dept. of Planning, Engineering & Permits | $90,000-$180,000 | $1,100-$1,350/mo | 3/10 |
| Huntsville | N/A — detached ADUs prohibited (Sec. 73.5; Sec. 10.6.3 bans kitchens in detached accessory structures) | N/A for ADUs — rear dwellings prohibited | Confirm with Huntsville Development Services | $95,000-$185,000 | $1,000-$1,200/mo | 2/10 |
| Mobile | 1,000 sq ft gross floor area or 50% of the principal structure's floor area, whichever is less (Sec. 64-4-2.B.3(a)) | Same as underlying zoning district rear-yard setback, or Historic District Overlay if applicable (Sec. 64-4-2.B.4(a)) — confirm district value with Mobile Planning & Zoning | Per the City of Mobile permit fee schedule — confirm current amounts with Build Mobile Permitting & Inspections Division | $90,000-$175,000 | $1,000-$1,200/mo | 6/10 |
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