Topographic Surveys in Mill Valley, CA

Mill Valley writes its residential standards against surfaces a surveyor has to establish. Maximum height is twenty-five feet above natural grade to the highest point of the roof, and thirty-five feet only within the portion of the lot that is at least double all minimum setbacks. Setbacks apply to every structure more than eighteen inches above natural grade, including below-grade pools and hot tubs, and the interior side and rear setback scales with lot area at one foot per thousand square feet, between five and fifteen feet. Adjusted floor area counts space above fourteen feet in height at 150 percent. Every one of those rules resolves to the same question: where is natural grade, and where exactly are the lines it is measured against.

Water and slope add the rest. No structures are permitted within thirty feet of the top of bank of Warner Canyon, Corte Madera, Sutton Manor, Old Mill, or Reed creeks, and on an incised, wooded channel like Arroyo Corte Madera del Presidio, top of bank is a field determination, not a line traced off an aerial. Minimum lot area and width requirements change for lots with more than ten percent slope, and effective lot area is the gross area less any portion encumbered by a trail easement or a recorded driveway or roadway easement, so the terrain and the easements both shape what can be built.

These are exactly the sites a conventional topo handles badly: steep, brush-covered, redwood-shaded, reached by a stairway or a one-lane road. Our Trimble terrestrial laser scanner captures the whole slope, the retaining walls, the creek bank, the tree trunks, and the existing house from stable setups in one visit, and we filter vegetation in processing to extract a bare-earth model under the canopy. Deliverables are 1-foot contours or tighter, a DTM, spot elevations, top-of-bank and wall geometry, and a layered DWG base map, plus the registered point cloud. See our Mill Valley ADU surveys and 3D laser scanning in Mill Valley.