Adu services — San Francisco, CA | AccessoryDwellingUnit Services

Looking for adu services 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

ADU services manage the technical side of building a backyard cottage or garage conversion. From verifying local property setbacks to plumbing and electrical connections, these professionals handle the logistics required to make a structure legal and habitable. You should reach out for these services when you have an idea for an extra living space but need a professional to ensure the project meets all safety codes and city regulations.

Frequently asked in San Francisco

What are the disadvantages of ADUs?

Disadvantages can include the high cost of construction in San Francisco and the limited space available for new structures. You must also adhere to stringent city zoning and building codes, which can be complex. Weighing these against the benefits of increased property value and rental income is crucial.

How much does an ADU cost in California?

What are the rules for ADUs in California?

California has state laws promoting ADUs, but San Francisco has its own specific ordinances and review processes. These regulations often cover density limits, setbacks, height restrictions, and parking requirements. Understanding these local rules is essential for compliance.

Is ADU allowed in Maryland?

Our services are focused on San Francisco, California. ADU regulations are very specific to each city and state. If you are seeking ADU services in Maryland, you will need to locate providers and information that cater to that particular region.

Can I build an ADU on my small lot in San Francisco?

San Francisco has regulations that often allow ADUs even on smaller lots, especially with recent state reforms. However, specific lot size, zoning, and existing structures play a role. A professional assessment will confirm your property's suitability and guide you.

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: The Richmond District, The Sunset District, The Castro, The Mission District, Pacific Heights — and every surrounding area.