Topographic Surveys in San Francisco, CA

San Francisco is the one Bay Area city where the topographic survey and the site survey are the same deliverable. Planning's plan-submittal guidelines require a site survey, signed by a California-licensed surveyor, for new buildings or whenever staff request one, and state plainly that a site plan cannot substitute for it. That survey has to carry specific elevations: the curb, the existing grade at the midpoints of the adjacent buildings' front walls, and the roof, eave, and peak elevations of the neighbors — the numbers Planning uses to test height, the Residential Design Guidelines' topography principle, and how an addition steps with the block. On a city of more than fifty hills, those elevations decide projects. Twin Peaks, Bernal Heights, Glen Park, Diamond Heights, and the Sutro slopes routinely exceed the 4:1 (25 percent) average-slope threshold of the Slope and Seismic Hazard Zone Protection Act (Building Code Section 106A.4.1.4), which pulls in geologist and geotechnical reports and, for larger additions, shoring, retaining walls, or grading over 50 cubic yards, Department review that starts from a measured ground surface. Edgehill Mountain and Northwest Mount Sutro have their own long-standing protection areas.

Control is the other San Francisco specialty. Public Works' County Surveyor established CCSF-CS13, a citywide coordinate system, by Record of Survey 8080 in 2014, and CCSF-VD13, the city's vertical datum, is a direct realization of NAVD88 — not an offset from it. The old City Datum sits roughly 11.35 feet below VD13, and the County Surveyor specifically prohibits converting old benchmarks by adding a constant, so we tie every topo to current published benchmarks and monument lines. Our Trimble terrestrial laser scanner then captures the whole site — the lot, the sidewalk and curb, the neighboring facades, and the rear-yard slope behind a 25-foot-wide row house — from a handful of setups, and we extract contours, a digital terrain model, spot elevations, and a layered DWG base map, with the neighbors' eave and ridge heights measured from the point cloud rather than estimated. Anything the architect asks for later is already in the cloud.

We deliver a stamped site survey, DWG/DXF base map, and the registered point cloud, on CCSF-CS13/VD13 or the datum your engineer specifies. For steep-lot boundary questions see our San Francisco surveying page, and for existing-building documentation our San Francisco as-built surveys.