Where does the time go in San Francisco's building-permit review? Stations, review rounds and the state clocks, from public data

San Francisco's building-permit review sends each new-housing permit through several city offices, round after round. Using the City's public permit and routing tables, we pre-registered a split of filing-to-issuance time by station and review round and tested it on 368 permits issued from August 2025 to October 2026. Round 1 holds about 75% of review days, led by Planning's CP-ZOC station, and the station ranking reproduces from the earlier window (rank correlation 0.95). About 47.5% of review rounds ran past California's 30- or 60-business-day limit on our measure, an upper-end estimate that cannot see pauses the law allows. The city's median share of elapsed time is 0.445 counted from arrival at a station but 0.045 counted from reviewer start, and 0.589 in the earlier window, so it depends on definition and window. Public data did not reproduce the Board of Supervisors' 280-day median or its DBI and Public Works figures. Data credit: City and County of San Francisco, DataSF open data portal, Building Permits (i98e-djp9) and Building Permit Addenda with Routing (87xy-gk8d), both under the Open Data Commons Public Domain Dedication and License (PDDL). State law text from California Legislative Information (leginfo.legislature.ca.gov). This work is not endorsed by the City. Paper: CC BY 4.0. Code in supplement.zip: MIT licence.