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
In San Diego, an ADU contractor understands the specific coastal commission rules, fire safety codes, and local density incentives that apply to your property. Because regulations here are quite specific, you need a contractor who is experienced with local planning departments to avoid delays. Whether you are adding a unit in a hilly area or a flat lot, a local pro helps ensure your project stays compliant with all regional requirements from day one.
Frequently asked in Berkeley
How do ADU projects differ in older versus newer homes in Berkeley?
What is the typical cost of accessory dwelling unit construction in Berkeley?
What are the rules for accessory dwelling unit construction in Berkeley?
What are some options for homes with mother-in-law suites in Berkeley?
How do I find an accessory dwelling unit contractor in Berkeley?
What are accessory dwelling units (ADUs) and what are their benefits?
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: Berkeley Hills, Elmwood, Gourmet Ghetto, West Berkeley, South Berkeley, North Berkeley — and every surrounding area.
Areas we serve
Browse by state, then city.
