Self-built by the owner’s family, this compact concrete house for an avid surfer overlooks the Pacific Ocean just south of San Francisco. Located on a small hillside site with stringent community zoning restrictions, the home’s roof gently contorts as a single curved plane to maximize light and view within the complex zoning envelope and community design restrictions. The frequently fogbound and chilly site required a sheltering form to provide pleasant indoor/outdoor living, as well as large expanses of privacy-filtered glazing to bring sunlight over the shoulder from the southeast-facing rear of the house. For simplicity of appearance and minimization of cost and resource consumption, the house is constructed of just two primary materials inside and out—bush-hammered, site-cast concrete, and sustainably-harvested Peruvian redwood imported and milled on site by the owners. The 12” thick concrete walls are cast monolithically with rigid foam insulation between two reinforced layers of concrete, affording a massive wall exposed inside and out. This two layer concrete wall system affords a robust, low-maintenance exterior, high insulation values, and excellent interior thermal mass. Windows, doors, flooring and millwork are hand built and finished by the owners on site. The main ceiling is an arcing plane of Peruvian redwood paneling warped down to follow the natural street slope at the front of the home—as required by local zoning—while warping back in the opposite direction at the rear of the home to minimize sunlight shadowing of the neighbor property —as also required by local zoning. This contradictory formal constraint creates the subtly dynamic warped form and interior space of the home. A glass clerestory box pierces this curving roof plane, creating a stairway, light and ventilation shaft through the center of the home, and providing access to a roof deck with concealed photo-voltaic and solar hot water equipment.