Accessory dwelling unit permit cost — Austin, TX

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 Austin

Also serving nearby: Round Rock · Georgetown · New Braunfels · Killeen · Temple

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

Service area details

Serving all of Austin — population 979,882; about 3,002 residents per square mile across 326.4 sq mi. ZIP codes covered include 73301, 73344, 78701, 78702, 78703, 78704, 78705, 78708.

Neighborhoods served in Austin: South Congress, East Austin, Barton Hills, Travis Heights, Hyde Park — and every surrounding area.