ADU Surveys in Santa Rosa, CA

Santa Rosa's ADU Requirements and Application Checklist starts by asking you to characterize the parcel, and the checkboxes tell you what the city is worried about: flood plain, steep slopes, hillside, and geohazard or landslide zone. Any of those turns a routine backyard unit into a project with a soils report and a plan review letter from a soils engineer. The submittal itself is a full building permit package, five sets at 24 by 36 inches, and it lists a site plan and a grading plan as separate required sheets, alongside architectural, structural, and MEP drawings. The checklist also flags fire sprinklers if any part of the ADU is more than 150 feet from fire department access or 400 feet from a water supply, school fees above 500 square feet, and capital facilities and parks fees above 750.

Distance and slope are both survey measurements. The 150-foot and 400-foot triggers are measured from real access and hydrant locations, not from a rough sketch, and whether your yard qualifies as steep slopes or hillside comes from actual topography. Santa Rosa does not publish a requirement that a licensed surveyor prepare the plans, but the universal rules hold: setbacks are measured from the legal property line rather than from a fence, and inspectors frequently require a surveyor to verify foundation forms before the pour. On rebuilt lots in Coffey Park and Fountaingrove, where fences and improvements were lost and replaced, a fence is an especially poor proxy for a boundary.

One Trimble scanning visit covers all of it: boundary corners recovered and staked from record research, the existing house with eaves and projections, hardscape, trees, utilities, hydrant and access distances, and dense elevations that produce both the site plan and the grading plan the checklist requires. Deliverables are a stamped base map and layered DWG. For slope-driven design see our Santa Rosa topographic surveys, and our Bay Area ADU survey guide.