From the adobe dwellings of the Anasazi Indians to the mud structures of Africa, people have built houses made of earth for centuries. At the 2005 Custom Home of the Year in Sonoma County, Calif., this ancient building tradition merges with a streamlined Modern design for a result that would impress in any era or time zone. “The house seems like it's growing out of the earth,” said one design awards judge. “It's a brilliant concept.”
The home's walls consist of rammed earth, a construction method that's won many fans over the past few years. The slightly irregular stratification along rammed earth walls creates a handmade quality, and the material's unique texture and color can make a house feel permanent and part of the earth in a way other methods can't. “This was our first rammed-earth project, and I hope not our last,” says architect Joshua Aidlin. “Our clients had moved out to the West Coast from the Midwest, where much of the architecture is masonry, and they were wary of the light stucco construction here. We toured some rammed-earth houses, and they loved them.”
The earth for this particular project comes from a nearby quarry. Custom builder Bill Maudru's crew used a roto tiller to mix it with sand, cement, and a little bit of water atop a clean, on-site concrete slab. With pneumatic hand compactors they layered the mixture between plywood forms, creating the home's 18-inch-thick walls. The sturdy walls sit on footings of concrete blended with an aggregate and then sandblasted. Steel wide flange beams held up by the rebar-reinforced rammed earth run along the top of each wall, helping to support the glulam roof beams. Most of the plumbing and electrical systems are placed within the poured concrete floor or wood-framed interior walls, since locating them in rammed-earth walls tends to complicate construction.
In addition to its beauty and sense of solidity, rammed earth also has sustainability on its side. The material is non-toxic, locally obtained, and made from an abundant natural resource. But the house comes up green in other ways, too. Aidlin, partner David Darling, and project architect Peter Larsen set up the floor plan to maximize energy efficiency, lining much of the east elevation with glass to capture the winter sun. During the summers, of course, the owners desire the opposite effect, which is where extra-long roof overhangs come in. “The eaves cantilever 8 to 10 feet past the building envelope,” says Aidlin. A pop-up clerestory running along the home's main circulation spine helps with natural ventilation and daylighting.
The architects carved that spine from the edges of the major rooms, rather than taking up more space with separate hallways. The strategy keeps the house open to views of the mountain and valley to the east and the garden to the west. And instead of separating the main public spaces with full walls, they divided them with pieces of cabinetry to further enhance the flow of light and wine country scenery. “It provides a more gracious spatial feeling that connects directly to the exterior,” Aidlin says. “You always have a view of the mountain and valley or the garden.”
While the owners are living in the home now, their stay is only temporary. They're building a main house on the property, and when it's finished they'll move there, turning their little rammed-earth gem into a caretaker's residence. With a perk like that, the job of caretaker will be a cinch to fill.
Entrant/Architect: Aidlin Darling Design, San Francisco
Builder: Cello & Maudru Construction Co., Napa, Calif.
Landscape architect: Marta Fry Landscape Architects, San Francisco
Lighting designer: Revolver Design, Oakland, Calif.
Structural engineer: Ingraham DeJesse Associates, Berkeley, Calif.
Civil engineer: Adobe Associates, Santa Rosa, Calif.
Geotechnical engineer: Giblin Associates, Santa Rosa
Rammed-earth consultant: Herman Bojarsky, Sonoma, Calif.
Cabinetry: Denning Cabinetry, San Francisco
Living space: 2,920 square feet; Site: 32 acres
Construction cost: Withheld
Photographer: JD Peterson (except where noted)
Resources: Bathroom/kitchen plumbing fittings: Dornbracht; Bathroom plumbing fixtures: Diamond Spas, Just, and Toto; Bathroom/kitchen cabinets: Denning Cabinetry; Ceramic and glass tile: Ann Sacks; Countertops: Simpson Sheet Metal; Dishwasher: Gaggenau; Entry and interior doors/trim work: Northstar Woodworks; Garbage disposer: Franke; Hardware: FSB 404, McKinney, Pemko, and Rixson; Kitchen plumbing fixtures: Simpson Sheet Metal; Oven: Bosch; Paints: Benjamin Moore and Cabot's; Patio doors: Fleetwood and Vistawall; Range: Thermador; Refrigerator: Sub-Zero; Structural lumber: Trus Joist.