How much does an ADU cost in San Francisco?
ADU costs in San Francisco
The median estimated construction cost on San Francisco ADU permits for one- and two-family homes was $100,000 over the last 12 months.
San Francisco at a glance
- Median estimated construction cost, ADU permits on one- and two-family homes, last 12 months
- $100,000
- Issued ADU permits, all property types, last 12 months
- 223 permits
- Share of issued ADU permits on one- and two-family homes, last 12 months
- 77.6%
San Francisco Department of Building Inspection, Building Permits (DataSF) · data as of
- Numbers from SF DBI public records
- Up to three local contractors, never a long list
- Free, no obligation
San Francisco ADU permit figures
San Francisco ADU permit figures
Local numbers for San Francisco, each with its source and date.
- Median days from filing to issue, ADU permits on one- and two-family homes, last 12 months1
- 204 days
Estimated ADU construction cost on San Francisco permits
| Project | Figure | Range on a shared scale |
|---|---|---|
| Median estimated construction cost, ADU permits on one- and two-family homes, San Francisco, last 12 monthsEstimated cost on the permit application, not a contract price. Covers one- and two-family homes only. | $100,000 |
Bars share one scale, from $0 to $100,000.
The figure is the median estimated construction cost written on San Francisco building permit applications for one- and two-family homes over the last 12 months. It is what the applicant expected the permitted work to cost, not a contract price or a quote. The real project cost is often higher. Get an estimate for your home.
Planning your project
The median estimated construction cost on San Francisco ADU permits for one- and two-family homes was $100,000 over the last 12 months. That is the most useful public figure for a starting point, but it is not the price of your project.
What the permit estimate means
The estimated cost is the number the applicant wrote on the permit application. It shows what the applicant expected the permitted work to cost. It is not a contract price, a bid or a quote, and it does not describe your home.
What usually adds to the real cost
Design, materials, finishes, and work that is not on the permit all change the total. The condition of your home also matters, since older systems and hidden repairs often come up once work starts. The real project cost is often higher than the permit estimate.
How to know your number
The way to know the cost for your project is an estimate for your home. A local builder can review your plans and your site, then give you a figure based on your project. Request a free, no-obligation estimate to start.
ADU cost questions for San Francisco
Is the permit's estimated cost the real cost of an ADU?
No. The permit figure is the estimated construction cost the applicant wrote on the application. Over the last 12 months, the median for ADU permits on one- and two-family homes in San Francisco was $100,000. Design, finishes, work not on the permit and the home's condition can all push the real cost higher.
What drives the price of an ADU in San Francisco?
Scope and finishes matter most. Design choices, materials, the level of finish, site access, utility work, and repairs needed in the existing home all add cost. Work that is not on the permit is also not in the permit figure.
Why do cost estimates differ from one project to another?
Each home is different. Two projects with similar permit estimates can end up with very different totals once the design, finishes and site conditions are set. A quote based on your plans and your home is more useful than a citywide median.
How do I get a reliable number for my home?
Describe your project and ask for a free, no-obligation estimate from a local builder. The builder who receives your request can look at your goals and your home. You can also check any contractor's license status with the Contractors State License Board (CSLB).
Does an ADU need a permit in San Francisco, and how long does it take?
Of 223 ADU permits issued in San Francisco over the last 12 months, 77.6% were on one- and two-family homes. The median time from filing to issue for those one- and two-family permits was 204 days. Ask the builder what permits your project needs and how long they may take.
Recent work by a contractor in our network
Photos from the contractor's own projects, used with permission. Captions name the type of work.
Bathroom in an ADU 
Addition / ADU interior 
Addition / ADU interior 
Addition / ADU bathroom
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