Accessory dwelling unit permit cost — Huntsville, 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 Huntsville

Also serving nearby: Chattanooga · Murfreesboro · Birmingham · Franklin · Hoover

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

Service area details

Serving all of Huntsville — population 225,564; about 1,008 residents per square mile across 223.6 sq mi. ZIP codes covered include 35801, 35802, 35803, 35804, 35805, 35806, 35807, 35808.

Neighborhoods served in Huntsville: Five Points, Twickenham, Five Points South, Maple Hill, Lakeshore — and every surrounding area.