South Mountain Company, a design/build firm on Martha’s Vineyard, Mass., has been toiling in the vineyard of green building for some 30 years. When sustainability flickered at the edges of the public’s consciousness, the company maintained a steady focus, continuously refining an approach that combines site-sensitive design, energy efficiency, and recycled and salvaged materials. But even the most capable and committed builder will have trouble being greener than those who sign the checks, and company founder John Abrams had a good feeling about the owners of this house from the start. They had already given control of 86 of their 100 shorefront acres to the Nature Conservancy for the restoration of a rare sand plain ecosystem, retaining only two 7-acre build-able parcels for themselves. Given that opening act, Abrams judged the couple “predisposed to be the best kind of clients for what we do.” When they sprang the idea that their new house should be a net energy producer, Abrams knew he had hit the jackpot. Putting it mildly, he says, “We were kind of pleased.”
South Mountain brings a load of technical sophistication to the task
Low-profile massing, no-finish cypress siding, a minimum of painted surfaces, and a front porch framed in driftwood signal a house intended to become part of its site, rather than dominate it. Photo: Brian Vanden Brink of green building, but it is motivated in part by a simple disdain for waste. So this project began with a thorough assessment of the site’s existing resources. Sand plains in their natural state are grasslands, maintained by periodic burning. After a century or more of fire suppression, much of this site had grown into forest, parts of which the Nature Conservancy would clear as the first stage of restoration. “Before they did their cutting,” says South Mountain architect Derrill Bazzy, “we went around and identified trees for use in the house.” Abrams adds that trees weren’t the only invasive species. “There was a large, ungainly, ugly house very close to the water, and it dominated the view of the pond.” That building made a graceful departure, under the auspices of the Island Affordable Housing Fund, to become two moderate-income dwellings elsewhere on the island.
Photo: Brian Vanden Brink Abrams and Bazzy sited the new building well back from the shore, minimizing its intrusion on the pond. A relatively low, single-story shell and L-shaped plan further reduce the building’s visual footprint, as does the cypress clapboard siding, which will weather to a silvery gray that blends into the landscape. After only a year’s seasoning, Abrams says, the house already Stripped and polished, the trunks of island oaks harvested on the site support a loft over the great room. The building’s floors, casework, and exposed structural framing are all of salvaged wood. Photo: Brian Vanden Brink “feels a little bit like the vegetation.” And well it might, with the prominent role local vegetation played in shaping its character. A driftwood arch surmounts the entry porch like the sun-bleached jawbone of a whale. The sinuous trunks of island oaks harvested on the site serve as columns in the great room. “Ninety-five percent of the interior and exterior visible wood is salvage of some sort, or from the site,” Abrams says. “The only important part of the building that isn’t is the stick framing.” Floors are old-growth heart pine recovered from river bottoms, where they sank in log drives a century ago. Interior trim and cabinetry is cypress that took a similar mud-bound hiatus, now dressed up with a light oil finish. The same wood, milled into clapboards, makes what Bazzy describes as an ideal siding. “It really will last indefinitely without a finish.” Doors are fabricated from super-stable old-growth redwood salvaged from retired beer vats. Non-wood materials, too, were carefully chosen for function, beauty, and environmental good sense. The slate-look roof shingles are reincarnated from junked car bumpers. Ceramic bathroom tiles make use of recycled windshield glass. The triple-glazed windows feature a custom muntin pattern inspired by the surrounding trees. The combined result is resource conservation without functional or aesthetic compromise. But the client’s program set a very specific performance goal as well. “The challenge here was to make a very, very low-energy house,” Abrams says. “So a 10-kilowatt Bergey wind turbine could power the whole thing.” Working backward from that target, the designers specified an energy-efficient shell and kept a running tab on the electrical loads the building’s systems would impose. The 6-inch exterior walls are filled with dense-pack cellulose insulation—another recycled material—and covered on the outside with an inch of rigid foam.
Photo: Brian Vanden Brink Overhead, the 2×12 rafter bays are also packed with cellulose and tightly sealed—with no ventilation. “Here on Martha’s Vineyard we’re in a very damp environment,” Bazzy explains, and introducing humid outside air into a roof system is not a good idea. “We’ve been doing our roofs that way for 20 years.” Meticulous gasketing and vapor-barrier paint obviate the need for a separate vapor-barrier membrane. “We’re using the Sheetrock and plaster layer as a vapor barrier.” Using electric power for space heating in the Northeast makes economic sense only if you can grow your own, but with a wind turbine planned for the site (see “Waiting for the Wind,” below) it was the natural choice. A ground-source heat pump, which draws on the earth’s latent heat by circulating water through four 300-foot drilled wells, works so efficiently that energy consultant Marc Rosenbaum’s calculations indicated no need for an exotic refrigerator or other specialty appliances. Energy-Star-rated equipment will keep the house’s energy consumption comfortably below the ceiling set by the wind turbine’s annual power output. “The energy efficiency of the house is incredibly high,” Bazzy says. “The ground-source heat system has worked very well,” and a blower-door test confirmed the tightness of the shell. “It’s doing its job very well that way.”
But while the house is working uncommonly hard, it shows no sign of strain. The very features that make it energy efficient, resource conservative, and gentle to its site also make it comfortable, beautiful, and uniquely suited to its setting. The design and craftsmanship that make it luxurious will also help it last a very long time. A sustainable building, after all, should be one worth sustaining. And this one is a keeper.
Resources:
Builder/Architect: South Mountain Company, West Tisbury, Mass.; Living space: 3,946 square feet; Site size: 99 acres; Construction cost: Withheld; Photographer: Brian Vanden Brink (except where noted). Click here for product information.
Web sites: South Mountain Company: www.somoco.com; Authentic Roof: www.authentic-roof.com; Climate Master: www.climatemaster.com; Bergey: www.bergey.com.
Photo: Derrill Bazzy Waiting for the Wind
On sites like this one, blessed with steady breezes and a power pole at the road, a wind turbine works like a dream. The wind blows, the blades turn, and the juice flows—at a cost lower than that of an equivalent photovoltaic system. When the wind dies, the house draws from the power grid; when the generator produces more power than the house needs, the electrons flow upstream, spinning the meter backward and helping power the other homes in the neighborhood. The key, aside from the technology itself, is “net metering,” an arrangement under which the local utility agrees to credit site-generated power at the retail rate.
So why is this house still waiting for its windmill? Like the proposal to build an offshore “wind farm” in the waters of Nantucket Sound, this installation hit a snag in the approval process. And as with that more famous project, the central issue was visual impact. But after being turned down by the local planning board, which ruled that the generator would be too visible from a public waterway, South Mountain Company has submitted an alternative location to the zoning board of appeals and is optimistic about winning approval. In the meantime, the company has shown its support for wind energy by standing up a 10-kilowatt generator at its own headquarters and shop (right), where it supplies half of the company’s electricity. “It’s not ugly; it’s not noisy,” says architect Derrill Bazzy, who invites concerned or curious neighbors to visit and see for themselves, “instead of just imagining what it could be.”
