Computed from 189 recent building-permit filings in San Francisco, CA — what people actually declared, not survey guesses.
✓ Verified from 189 recent building-permit filings in San Francisco, CA
Every filing behind this range declared a residential renovation cost between $1,000 and $2,000,000 — outliers and commercial-scale projects are excluded. We only publish a range once at least 30 qualifying filings exist for a city/project combination; this one has 189.
Data refreshed September 2026
The short answer: a typical adu / garage conversion in San Francisco costs around $60,000, with half of all projects landing between $16,445 and $150,000. If a quote falls well outside that range, it isn't automatically wrong — but it deserves an explanation you can understand.
San Francisco's housing stock skews toward older Victorian and Edwardian construction on narrow lots, which constrains access for equipment and can add labor time versus a comparable suburban project.
Mild, fog-moderated weather keeps most exterior trades workable year-round, so seasonal price swings are smaller here than in cities with harsh winters or summers.
The middle half of the published sample spans $16,445 to $150,000. That is a 223% spread around the median, so the details of your scope matter more than the label on the project.
An ADU or garage conversion can include habitable-space upgrades, insulation, fire separation, windows, services, kitchen or bathroom work, and finishes.
New utility meters, sewer upgrades, site work, demolition, furnishings, and major foundation or roof reconstruction may not be included.
This guide is based on 189 qualifying permit filings, not completed projects. Permit values reflect what applicants declared and can differ from the final paid cost.
Every figure on this page is computed from declared valuations on building permits filed with the San Francisco Department of Building Inspection (DBI), published via DataSF, the city's open-data portal. We report the 25th percentile, median and 75th percentile of 189 recent residential filings — never a single-point "average". Declared values are what applicants file, not final invoices, so treat the range as planning guidance rather than a quote. Full methodology →
The source dataset is maintained by the San Francisco Department of Building Inspection (DBI). The published sample is the subset classified as residential, matched to this project type, and carrying a declared valuation from $1,000 to $2,000,000. The count above is the number of qualifying filings used for this city and project, not the number of homes or completed invoices.
Open DataSF, the city's open-data portal datasetBased on 189 recent building-permit filings with the San Francisco Department of Building Inspection (DBI), the median declared cost is $60,000. Half of all projects fall between $16,445 and $150,000.
No. Permit valuations are what applicants declare to the San Francisco Department of Building Inspection (DBI) when filing, not final invoices — and the San Francisco Department of Building Inspection (DBI) doesn't independently verify the declared value. Treat the range as planning guidance and a sanity-check against the quotes you receive, not a price to hold a contractor to.
San Francisco's housing stock skews toward older Victorian and Edwardian construction on narrow lots, which constrains access for equipment and can add labor time versus a comparable suburban project. That local variation is on top of the usual differences in size and specification, which is why we publish the 25th percentile, median and 75th percentile instead of a single misleading "average" — you can see where a quote sits in the real distribution.
Planning something else, or somewhere else? Request a city or project — requests decide what we ingest next.