ADU Surveys in Sausalito, CA

Sausalito's ADU permit application is unusually specific about survey involvement. For attached and detached units the submittal checklist calls for a story pole plan indicating the placement of story poles and tape, and a story pole certification consisting of a letter from a certified land surveyor certifying that the story poles have been installed pursuant to the story pole plan. The site plan, existing and proposed, must show all property lines, the location of existing units and the ADU, and the location and dimensions of parking spaces; the elevations must depict height from average natural grade. Story pole plans and certification appear again in the design review submittal list in SMC section 10.54.060, so this is not an ADU quirk — it is how Sausalito evaluates bulk and view impact.

Those requirements land on the hardest lots in Marin. New attached and detached ADUs must provide side and rear setbacks of at least four feet, measured from the legal property line rather than from a wall or fence that has moved over a century of terracing. The city's ADU standards also address view and shading directly: an ADU cannot block or obstruct primary views from neighboring properties, and its incremental light and shadow impact must not affect more than 25 percent of an adjacent parcel more than 30 days a year, with a shadow study possible. Every one of those tests needs measured neighbor geometry and measured ground, not estimates.

Our scanner captures the lot in one visit — slope, wall faces, stairs, the existing house, and neighboring eave and ridge heights — so average natural grade is computed, story poles are set from real coordinates, and the certification letter rests on field measurement. Deliverables are a stamped site survey, contours and spot elevations, a layered DWG base map, corner staking, and story pole layout and certification. See Sausalito topographic surveys and our Bay Area ADU survey guide.