SB Architects overcome a challenging site to produce Marin County's first LEED Platinum home
Tucked into a steep, hillside site just across from the Golden Gate Bridge in San Francisco, this custom home is the first LEED Platinum home in Marin County, and the second LEED Platinum home in Northern California. The goals for the design of this home were at once far-reaching and very close to home. The product of a dynamic collaboration between client / architect, interior designer, builder and a host of project partners who came together to create a project that would push the boundaries of sustainable design for custom homes, this new home was also designed by the architect for his own family.
The design challenges, and ensuing opportunities, began with the site selection. Steep, narrow and filled with valuable existing oak trees, the lot seemed nearly unbuildable. However, architects are well known for being drawn to deeply challenging sites - particularly those within easy walking distance of one of the most desirable downtowns in the Bay Area. The resulting design was in every way a direct response to the site, trees and stunning views of downtown San Francisco. The architecture is a careful balance between modern sensibilities and the rustic, natural surroundings - a sustainable modern cabin. Set deep into the hillside, nearly 20% of the home's total square footage sits below grade. The hillside provides the lower floors with natural insulation, solar power supplies electricity and hot water, and radiant floor heating and an innovative air re-circulation system condition the interior. Local availability, recycled content, energy conservation and sustainable production drove the selection of every system, material, appliance and design detail.
A central circulation core connects four levels of living spaces, each of which embraces the outdoors through expansive windows and decks. Every window opens to a view of the trees. Glass walls in the master suite retract and disappear to virtually eliminate the boundary between indoors and out. Covered outdoor spaces - an open-air entry and yoga deck protected by cedar rain screen, an indoor-outdoor family room directly off the kitchen - make the small conditioned footprint of this house live as if it were much larger. On the interior, rustic meets modern once again. Steel cross beams left to weather in the rain, ceilings of reclaimed fir from a deconstructed seed plant, and interior stairwell lined with discarded scaffolding beams (rendered unusable by new OSHA standards) promote the cabin vernacular. Open spaces, industrial materials, sleek wood finishes and high-efficiency automated systems keep the design from being referential. In the living area, paired joists allow a ridge beam to span 36 ft, negating the need for columns in this expansive space.
The verticality of the architecture is carefully balanced by a multitude of horizontal elements. Horizontal cedar siding and rain screens, steel railings and detailing on the garage door ground the architecture on the exterior. Horizontal boards in the stairwell, and on all of the cabinetry, balance the soaring interior spaces. The elegant simplicity of the massing gives a modern edge to the traditional cabin vernacular, while the palette of Western Red Cedar, steel, stone, integrally-coloured eco-plaster and three shades of grey walks a similar line between industrial and natural. This highly sustainable design solution offers an architectural vocabulary that is a deeply authentic response to both its site and its multiple audiences - the family, the city, and the surrounding hills.