Accessory dwelling unit permit cost — Mobile, AL

Last updated: September 24, 2026

What affects the price

Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.

Frequently asked in Mobile

Also serving nearby: New Orleans · Montgomery · Jackson · Baton Rouge · Tuscaloosa

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More on this: HUD ADU resources — ADU policy and financing research.

Service area details

Serving all of Mobile — population 182,595; about 1,309 residents per square mile across 139.5 sq mi. ZIP codes covered include 36601, 36602, 36603, 36604, 36605, 36606, 36607, 36608.

Neighborhoods served in Mobile: Downtown Mobile, Spring Hill, Midtown, West Mobile, Crichton — and every surrounding area.