Where the data comes from.

The contractor index is built entirely from public records published by the City and County of San Francisco on DataSF. We sync daily and keep the last 10 years of home-scale permits that name a contractor: 443,597 permits right now.

Datasets

• Building Permits (i98e-djp9) and Building Permit Contacts (3pee-9qhc): every permit filed with the Department of Building Inspection since the 1980s: description of work, declared cost, status, dates, address and neighborhood, plus the contractor, architect, engineer and expediter on each job with their CSLB license numbers.
• Electrical Permits (ftty-kx6y) and contacts (fdm7-jqqf): panel upgrades, rewiring, solar and EV chargers, with the electrical contractor and business phone.
• Plumbing & Mechanical Permits (a6aw-rudh) and contacts (k6kv-9kix) : water heaters, repipes, sewer laterals, furnaces and heat pumps.

The 2026 PermitSF gap

Since February 2026 the city has been moving permit types into its new PermitSF system: windows, doors and siding (February), reroofing (June), electrical and plumbing (July) and kitchen and bath remodels (September). PermitSF's public dataset currently has no contractor, cost or work description, so new permits of those types can't be attributed to a contractor yet. Rankings for those categories lean on work filed before each switch-over. We'll add PermitSF contractor data as soon as the city publishes it.

How contractors are identified

Contacts are merged by California State License Board license number when present (over 99% of contractor contacts have one), otherwise by a normalized firm name. Firm name and address come from the most recent permit. Property owners named on permits are never stored or shown.

How work is categorized

Each permit's free-text description is matched against conservative keyword patterns for 20 categories (windows, roofing, kitchen remodel, bathroom remodel, seismic retrofit, foundation, electrical, plumbing, water heater, heating & cooling, solar & batteries, ev charger, adu & in-law units, additions & major remodels, decks & stairs, siding & facade, garage & driveway, fire sprinklers & alarms, demolition & abatement, new construction). A permit can belong to several categories. Patterns favor precision over recall: missing a job is better than ranking the wrong contractor.

How ranking works

Within a category, contractors are ordered by permits filed in the last 12 months, then the last 36 months, then recency, then lifetime volume. There are no paid placements.

Caveats

• Declared costs are estimates made at filing; final costs are often higher.
• A permit shows a contractor pulled it. It doesn't tell you the work was good. Check references and reviews.
• Unpermitted work, and work by unlicensed handymen (under $1,000), is invisible here.
• We don't vet, endorse or recommend contractors, and we don't check whether they're currently licensed, bonded or insured. A license number shown here is the one recorded on the permit. Confirm license status, bond and workers' comp at the CSLB before signing anything.

Keeping the guide current

Every number in the guide that changes over time (mortgage rates, loan limits, tax rules, company stock sales, insurance news) is tracked in a fact register with its primary source and a re-check cadence (weekly for rates and liquidity events). Each chapter shows the date its facts were last verified.

Page generated Oct 18, 2026.