The owners are a family of five who enlisted Mork Ulnes Architects to create a unique perch to host their extended family and guests. They requested three private guest areas, each with a separate entrance, en-suite bathroom, and outdoor terrace. To accommodate the separate suites, the building is composed of three distinct volumes. These volumes step down with the grade progressively, nesting into the site’s natural contours so that the mass of the building is softened into the hillside. A continuous, multi-gabled roof joins the units into a coherent whole while its peaks and valleys echo the hills beyond.

Given the regional ecology and desire for a low-maintenance project, robust, fire-resistant, board-formed concrete was chosen as the primary building material. Care was taken to craft almost the entire project in concrete. Concrete’s organic tactility and inherent ruggedness root it into the rocky hillside. As the building sits on a ridge prone to wildfire, concrete was an chosen for its fire resistance. When the property was engulfed in the 2017 Sonoma wildfire, the main house was severely damaged, neighbors' homes were destroyed, and the guesthouse was unscathed.

From the shared perspective of the adjacent plateau, the three volumes are solid, concrete prisms. Upon entering and passing through what feels like a heavy concrete threshold, the space expands and gives way to a total openness and continuity with the landscape. Diagonal roof ridges orient the space outward and upward to the panoramic hilltops in the distance. The floor slabs, rooted in the hillside, float out over the steep ground below and project each bedroom into its own private view.

Credits: Nordby Construction, ZFA Structural Engineers, Surface Design, The Office of Charles DeLisle

Credits: - ZFA Structural Engineers - Structural Engineer - The Office of Charles DeLisle - Interior Decorator - Nordby Construction - Contractor - Surface Design - Landscape Architect