Accessory dwelling unit companies

Looking for accessory dwelling unit companies in San Francisco, CA? Call AccessoryDwellingUnit Services for a contact a provider — no obligation. Licensed adu builders serve San Francisco and the surrounding area, and you'll get straight answers on timing and what affects the price.

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

These companies provide comprehensive support for homeowners, often pairing design experts with construction crews to handle the entire project under one roof. They are helpful when you want to avoid hiring separate architects and builders. You should look into these companies when you want a streamlined experience and a single point of accountability for your backyard project from start to finish.

Frequently asked in San Francisco

How much does an ADU cost in San Francisco?

What are the rules for ADUs in California?

Is an ADU allowed in San Francisco?

Yes, San Francisco actively supports ADU development, but with strict adherence to its detailed planning and building codes. These rules are designed to ensure ADUs are well-integrated into the city's fabric. Consulting local experts is the best way to navigate these requirements.

Funding opportunities vary by state and locality. The pros serving San Francisco can help you explore any available grants or incentives in the Bay Area.

What is involved in building an ADU in San Francisco?

What are the disadvantages of ADUs?

While ADUs offer many benefits, potential disadvantages include initial construction costs and potential impacts on privacy or parking for existing residents. You might also need to consider how an ADU will affect your property's landscaping or utility usage. Discussing these points with a local pro is important for a balanced perspective.

Also serving nearby: Daly City · Richmond · San Mateo · Berkeley · Oakland

All cities in California →

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

Service area details

808,988residents

17,323per sq mile

8ZIP codes served

Serving all of San Francisco — population 808,988; about 17,323 residents per square mile across 46.7 sq mi. ZIP codes covered include 94102, 94103, 94104, 94105, 94107, 94108, 94109, 94110.

Neighborhoods served in San Francisco: Mission District, Pacific Heights, Richmond District, Sunset District, Nob Hill — and every surrounding area.