Accessory dwelling unit construction cost — Berkeley, CA
Last updated: September 24, 2026
What affects the price
Building an ADU is a major project, and the final bill depends on a few key things. Site prep is a big factor; if your land is sloped or needs extensive utility connections, costs go up. The materials you choose—from siding to kitchen finishes—also change the math significantly. Whether you’re building a detached unit or converting an existing garage shifts the permit requirements and structural work needed. We provide exact pricing confirmed free on the call.
About this service
The cost to build an ADU varies based on whether you are converting an existing garage or building a new detached structure from the ground up. Factors like foundation work, utility extensions, high-end finishes, and site access all influence the final total. Exact pricing confirmed free on the call.
Frequently asked in Berkeley
What is the accessory dwelling unit construction process in Berkeley?
What are the typical ADU unit sizes in Berkeley?
What does ADU building involve in Berkeley?
What accessory dwelling unit services are available in Berkeley?
Can you recommend an accessory dwelling unit contractor in San Diego?
How do I find the best ADU in Berkeley?
What are the requirements for ADU housing in Berkeley?
Also serving nearby: Richmond · Oakland · Daly City · Vallejo · Concord
More on this: HUD ADU resources — ADU policy and financing research.
Service area details
Serving all of Berkeley — population 118,962; about 11,403 residents per square mile across 10.4 sq mi. ZIP codes covered include 94701, 94702, 94703, 94704, 94705, 94707, 94708, 94709.
Neighborhoods served in Berkeley: Gourmet Ghetto, West Berkeley, South Berkeley, North Berkeley, Downtown Berkeley — and every surrounding area.
Areas we serve
Browse by state, then city.