ADU Surveys in Kensington, CA

Kensington is unincorporated, so ADU applications run through Contra Costa County's Department of Conservation and Development under the county checklist: site plans with property lines and dimensions, easements, all structures with setbacks, water and sewer line locations for detached units, trees over 20 inches in circumference within 50 feet of construction, and a grant deed with the legal description. Then geography takes over. Kensington occupies a steep shoulder of the Berkeley hills, and the county's geotechnical trigger — a report may be required where the site slopes more than 5 percent, exemption only below roughly 25 percent on trouble-free soil — is less a trigger here than a standing condition. Most Kensington backyards fail the exemption on slope alone, and the community's soils history along the hill face makes the "no history of creep or settlement" test a real question rather than a formality.

The lots themselves compound it. Kensington's winding 1910s–1920s subdivisions produced small, irregular parcels on switchback streets — shared driveways, stacked retaining walls, garages at street level with houses above or below, and boundaries monumented a century ago where they were monumented at all. An ADU squeezed onto ground like this is designed in inches: setbacks from resolved lines, height against existing grade, drainage that legally cannot be shed onto the downhill neighbor. Our laser-scanned site survey is built for exactly this parcel type — boundary from deep record research, dense contours through the landscaping, walls with top and bottom elevations, and the neighboring structures that hillside massing decisions depend on, all from one visit without setting foot on adjacent property.

Records run through the Contra Costa County Recorder in Martinez. Deliverables are a stamped base map, layered DWG, and staked corners; for terrain-first work see our Kensington topographic surveys.