Looking for accessory dwelling unit companies in San Francisco, CA? Call AccessoryDwellingUnit Solutions 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 budget. The biggest factor is whether you choose a prefabricated unit or a custom build on-site. Site preparation is also significant; if your land requires extensive grading, utility trenching, or foundation work, costs will climb. Your choice of finishes—like kitchen cabinetry, flooring, and siding materials—also shifts the bottom line. We help you navigate these variables to find a setup that fits your property. Exact pricing confirmed free on the call.

About this service

ADU companies offer end-to-end solutions, often handling everything from the first sketch to the final walk-through. You need these companies if you prefer a streamlined experience where one firm takes responsibility for design, permitting, and construction. They are ideal for homeowners who want to minimize the stress of managing multiple vendors and prefer a turnkey approach to adding a secondary residence to their property.

Frequently asked in San Francisco

What are the disadvantages of ADUs?

Potential downsides to ADUs include the significant upfront construction costs and the impact on existing yard space or privacy in a dense urban environment like San Francisco. You'll also need to factor in utility connections and potential property tax adjustments. Consulting with local experts is crucial.

How much does an ADU cost in California?

The cost of an ADU in California, especially in a high-cost area like San Francisco, can vary substantially. Factors such as size, design complexity, material choices, and the necessary site preparations significantly influence the final price. A detailed quote from a qualified contractor is the best way to determine your specific costs.

What are the rules for ADUs in California?

California has state laws that simplify ADU approvals, but San Francisco has its own specific local ordinances. These rules cover aspects like maximum unit size, setbacks, parking requirements, and lot coverage. It's essential to work with professionals who are well-versed in both state and San Francisco regulations.

Is an ADU allowed in Maryland?

This service is specifically designed to assist with Accessory Dwelling Units in California, including San Francisco. Maryland has its own separate and distinct regulations for ADUs. For projects in Maryland, you would need to seek out local contractors and authorities who are knowledgeable about their specific zoning and building requirements.

While there might be other financial incentives or loan programs available in San Francisco or California, they would operate independently of this particular grant. Local resources can often provide information on current opportunities.

How do I start the ADU process in San Francisco?

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 Mission District, Nob Hill, The Sunset District, Pacific Heights, Haight-Ashbury — and every surrounding area.