Some architects approach sustainability from an energy-efficiency point of view, making houses that require as little power as possible. Others concentrate on materials, trying to source as many green elements as they can. And a brave few throw most of their environmental efforts into designing buildings that produce their own energy. McKinney Architects borrowed a little from each strategy for this sky-blue Austin, Texas, residence, with admirable results: The home's well-rounded sense of sustainability won it a rare five-star rating from Austin Energy's Green Building Program.
The project features a water-cooled, closed-loop air conditioning system that consumes 30 percent less energy than standard air conditioning. More commonly used in commercial and industrial buildings, the system incorporates an exterior cooling tower hidden by landscaping. “It's very quiet both outside and inside, which was an unforeseen benefit,” says principal-in-charge Heather McKinney, AIA. Spray-in foam insulation, double-pane low-E windows, and programmable thermostats help the house retain cool or warm air as the weather outside dictates. And fluorescent lighting—some mixed in with halogen bulbs and some used on its own—also saves electricity.
McKinney and project architect Brian Carlson worked with the clients, an Austin couple with two young children, to find green materials such as compressed-wheatboard cabinetry, low-VOC paints, and recycled-glass countertops. The original house on the property was clad in stone veneer, which the architects stripped off and reused in the retaining walls and fireplace of the new building. (The old house, meanwhile, was bought and moved to another site—the ultimate nod to recycling.) Hardwood floors consist of cumaru, also known as Brazilian teak, purchased from a sustainable lumber supplier. And eco-conscious cork covers the floors in the “messy room,” a multipurpose space for activities like art projects and flower arranging.
The building's shape—two long, “Monopoly house”-like forms connected by a slim glass link—lends itself to both photovoltaic panels and a rainwater collection system. Rain runs down off the pitched, standing-seam metal roofs and flows through gutters into a free-standing, 1,200-gallon backyard cistern. The clients use the water for landscape irrigation, so no filters are necessary. A three-kilowatt photovoltaic system sits unobtrusively on the south side of one roof; it's only visible from the side elevation, and then only upon close inspection. During cooler, non-air-conditioned months, it often provides all the energy the home needs to function.
The home's distinctive profile serves a purely aesthetic purpose as well. “We were really concerned with not doing something so massive that it overwhelmed the street,” says McKinney, speaking of herself, Carlson, and partner Al York, AIA. “Breaking up the massing by having two forms made it seem like a smaller house. We also liked the proportions of the two pieces. They're tall and narrow and have a playfulness to them that wouldn't have been possible with bigger forms.”
project: Robbs Run House, Austin, Texas
architect: McKinney Architects, Austin
general contractor: Bill Dorman Construction, Austin
landscape designer: Theresa Kwilosz, Austin
interior designer: Agnes Bourne, San Francisco
mechanical contractor: Allied Energy Systems, Austin
project size: 3,900 square feet
site size: 0.3 acre
construction cost: Withheld
photography: Greg Hursley, except where noted