Cost to build accessory dwelling unit — Los Angeles, CA

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.

About this service

When estimating the cost to build, consider the difference between a prefab unit and custom construction, as well as site preparation requirements like clearing trees or grading land. Labor and material prices also play a significant role. We provide an exact pricing confirmed free on the call.

Frequently asked in Los Angeles

Also serving nearby: Santa Monica · Inglewood · South Gate · Compton · Torrance

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

Service area details

Serving all of Los Angeles — population 3,820,914; about 8,120 residents per square mile across 470.5 sq mi. ZIP codes covered include 90001, 90002, 90003, 90004, 90005, 90006, 90007, 90008.

Neighborhoods served in Los Angeles: Hollywood, Santa Monica, Pasadena, Long Beach, Silver Lake — and every surrounding area.