ADU Surveys in Lafayette, CA

Lafayette writes the strongest survey language in Contra Costa County. For new-construction ADUs processed under the city's Class C permit, the checklist requires a certified survey for any development that encroaches within 5 feet of required setbacks — and specifies that the proposed site plans "shall be prepared upon the aforementioned survey." Since state law entitles ADUs to 4-foot side and rear setbacks, nearly every detached ADU in Lafayette sits well inside that 5-foot band, making the certified survey effectively standard. The same checklist requires a preliminary title report for every ADU class, existing topography at maximum 2-foot contour intervals in the development area including any mapped ridgelines, and surveyed locations of native trees 12 inches and larger — valley oak, blue oak, coast live oak, madrone, California bay among them.

Where grading is involved, Lafayette's plans escalate further: existing and proposed contours at 2-foot intervals extended 50 feet beyond the property lines, cut and fill quantities, retaining walls with top-of-wall and bottom-of-wall spot elevations, and creeks shown with their required setbacks in both plan and section view — Lafayette's creek setbacks can bar an ADU site outright, so finding them early matters. This is classic Lamorinda terrain: oak-studded slopes, long driveways, ridgeline lots, and drainage that runs through neighboring parcels. Our laser-scanned survey handles the whole stack in one mobilization — certified boundary, 2-foot contours through vegetation, surveyed trees with trunk diameters, walls with TW/BW elevations, and creek top-of-bank locations.

Lafayette issues building permits through Contra Costa County, whose geotechnical triggers ride along on sloped sites. Deliverables are a stamped survey and site-plan base map with a layered DWG, recorded through the County Recorder in Martinez. For terrain-first questions, see our Lafayette topographic surveys.