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How to keep it cool

Laura Fisher Kaiser -- Interior Design, 6/1/2003 12:00:00 AM

Recently named National Green Advocate of the Year by the National Association of Home Builders, Peter L. Pfeiffer believes in living the message. A principal of Barley + Pfeiffer Architects, renowned for mainstreaming environmentally responsive design and construction, he turned his own 4,000-square-foot house in Austin, Texas, into a veritable laboratory of green design.

For starters, the "up-country" craftsman-style residence is sited with its long axis running east-west, so the majority of windows face north or south—all with extra-broad overhangs. This critical strategy maximizes passive solar heat gain in winter. More important, Pfeiffer says, "It's great for receiving the prevailing southeast breezes. Even on the hottest of August days, the house and screened porch remain cool."

Pfeiffer intentionally chose electronic ballasted high-resolution fluorescent fixtures, which generate less heat than halogens and incandescents, but bringing in glare-free daylight remained a priority. Accomplishing this task—while keeping solar heat out—required multiple maneuvers. Windows at the top of the central stair tower open to siphon heat upward and outward, and a whole-house fan in the shaft draws air through the building. Pfeiffer also clad the eaves of the house in reflective Galvalume sheet steel and installed a foil layer under the recycled-metal roof surface to deflect solar radiation. A northeast-facing skylight in the roof of the screened porch brings indirect sunshine into the adjacent family room. Rigid-foam wall and attic insulation and the attic's lack of air vents maximize energy efficiency by sealing out humid heat.

Water plays a critical role, too. The house is heated by a hydronic system, which blows air across a hot-water coil, while a water-based air-conditioning system harnesses the swimming pool as a heat sink. Addressing conservation issues, Pfeiffer supplements landscape irrigation with rainwater, collected in a cistern, and "gray water," stored in an underground tank.

He estimates that, combined, all these features added 2 or 3 percent to the construction cost. A small price to pay, considering that—according to sophisticated computer models—his utility bills will be a third of those for a Southwestern house of comparable size.

With hard data behind him, Pfeiffer has trouble concealing his contempt for "cocktail green": the odd skylight or recycled carpet. "Real green," he says, means taking a thorough and scientific approach, from conception to finishes. "It has to be efficient in its use of energy, resources, and water. It has to be healthy in terms of materials and air quality. And it has to be beautiful."

From top: Green design pioneer Peter L. Pfeiffer of Austin, Texas. His open kitchen features woodwork finishes and a hardwood floor of salvaged heart pine; as in the rest of the house, paint is low-VOC.

Clockwise from top left: Windows in a second-floor sitting room contribute to the heat-siphon effect, in which hot air exits through upstairs windows while ones below draw in cool breezes. Windows at the top of the open central stair tower help light the house as well as cool it. The pale-colored exterior features local limestone and cementitious siding, made with recycled wood chips.