What makes a building green? A bewildering array of options are available to the architectural designer: solar panels, geothermal heat pumps, recycled plastic decking, tankless water heaters, low-emissivity glass, gray water collectors, bamboo flooring, zero-VOC paints. Where to begin? Award-winning architect Peter Pfeiffer, a principal of Barley & Pfeiffer Architects in Austin, Texas, has an answer that may surprise some.
“Put aside all the funky devices at first and focus on common-sense design," says Pfeiffer. “Site the house for its orientation to the sun, to control solar heat gain because that's the single most important thing you can do for energy efficiency." Pfeiffer should know — for more than a quarter-century, he has been at the forefront of environmentally sensitive design. His first residential project, completed while still in grad school at the University of Texas at Austin in the 1980s, was a home for his parents in New Jersey. The 2,500-square-foot house is still in the family today and has utility bills of $20 to $25 per month — in winter!
|Shaded patio for outdoor living at Peter Pfeiffer's Long Canyon project.|
Pfeiffer credits his parents with stimulating his early interest in building. When he was only 12 or 13 years old, they put him to work on weekends helping them remodel and maintain the rental houses they owned to supplement their income. At the age of 14, he decided on a career in architecture, and the first Earth Day inspired him to pursue high-performing environmental design. The oil embargo of the early '70s galvanized his desire to develop solar designs for energy efficiency. He majored in building sciences, with emphasis on solar design, at Rensselaer Polytechnic Institute, graduating in 1978.
The following year, Pfeiffer went to work for Houston architectural firm CRS, which was then designing what would be, at that time, the world's most energy-efficient high-rise. He later worked for the contractor building the high-rise, so he gained both design and construction experience on the project. He further pursued this “hands-on" approach to architecture as an apprentice to visionary architect Paolo Soleri, who was designing and building his Arcosanti project — a fusion of architecture and ecology — in the Arizona desert north of Phoenix. While earning his master's of architecture degree in solar design at the University of Texas, Pfeiffer studied and worked with Paco Aruni, a professor who developed one of the earliest computer models for assessing energy-saving design.
The economic boom of the '80s — an era of cheap oil — was not friendly to solar design. “I thought it was a sad day when Reagan removed the solar panels from the White House roof and declared the oil shortage over," Pfeiffer recalls wistfully, “but I stuck with solar design, gaining experience that would later prove important." He joined up with fellow University of Texas graduate Alan Barley to begin private practice, hooked on the idea of combining good-looking, well-thought-out design with highly energy-efficient building science. And he learned to shift the emphasis slightly, promoting design that would provide clients with greater comfort at lower cost — mainstreaming green before it was even called “green."
|Wide overhangs protect windows and main entry, Long Canyon.|
Asked about his top priorities for green building, Pfeiffer said, “First, design for reduced consumption of energy, water and materials. Second, make the house a healthier place to live. And, third, plan to avoid environmental degradation." His strategies to achieve these goals have been honed through long practice. “To lower energy consumption, the most important thing is to make sure the building responds to its solar orientation," Pfeiffer explains.
This means aligning the house, whenever possible, along an east-west axis, so that the longer sides face north and south. Generous overhangs — three to four feet, instead of the usual one or two — are needed to properly shade windows and doors, particularly on the south- and west-facing sides. Proper shading will minimize solar heat gain during summer and maximize solar heat gain during winter — saving energy and costs of mechanical heating and cooling. Because the solar trajectory varies with time and location, Pfeiffer uses a computerized Sun Angle Calculator to get it right. How about low-emissivity glass? “Good shading is more effective," says Pfeiffer, “than tens of thousands of dollars in unshaded, low-E double-pane glass."
And how effective are solar photovoltaic panels? “Using less electricity is a more efficient way to save than trying to generate electricity yourself," says Pfeiffer. He tells about his experience with his own home to illustrate the point. After installing a solar array at a cost of $26,000, he found that it shaved $35 to $45 off his monthly electric bill. At that rate, the payback period would be around 48 years — not taking into account the costs of maintenance during that period. He also installed a high-efficiency pool pump, at a cost of $800 more than the conventional pump it replaced, cutting electric consumption by 50% to 70%. That reduced the monthly electric bill by about $55 — which pays back the extra cost in only a little more than one year.
|Long Canyon living room features high-efficiency fireplace and lighting.|
Another strategy, almost as important as solar orientation, involves designing the house — with attention to alignment on the site, arrangement of rooms, and placement of doors and windows — to take advantage of pre-vailing breezes in spring, summer and fall. Good, natural ventilation will further reduce the need for mechanical air conditioning and contribute to making the house a healthier place to live. Indoor air quality can be enhanced by placing the garage on the downwind side of the house and completely detaching it or connecting it to the house by means of a breezeway. “That will prevent the intrusion of car exhaust and chemical vapors into indoor air," notes Pfeiffer. “Don't sleep with your Suburban…"
Moisture management, air infiltration control, insulation and reflectivity are all important strategies in creating a healthy indoor environment and boosting energy efficiency. Moisture and humidity from the indoors must be vented outdoors, while moisture from outside must be prevented from penetrating inside. A building envelope that can be tightly sealed and good insulation — to prevent heat gain in summer and heat loss in winter — are essential. Reflectivity of exterior surfaces (lighter colors in hotter climates, darker colors in colder climates) can also help to promote comfort and efficiency.
| Left Photo: Modern Green Home project is designed in the International Style. ||Right Photo: Exterior walls of Modern Green Home combine low-maintenance metal and smooth stucco.|
And as for those exotic materials, like bamboo flooring? “In the end, it makes the most sense to use renewable materials from your own region," says Pfeiffer. “For example, here in Central Texas, we have oak trees all over the place. Oak flooring would be a very renewable material, and one that doesn't have to be shipped in from 8,000 miles away. Bamboo flooring, although rapidly renewable, can represent a great deal of embodied energy, depending on where it's coming from and how it gets to your building site."
Pfeiffer insists that 90% of the opportunities for a high-performance green home are found in the first 10% of the design process. For that reason, he spends a lot of time with clients at the start, explaining the design process and involving them in a detailed consideration of the program. “We give them a programming guide to fill out, to tell us what they want in a house, which allows us to question them as to why they want those things and whether they are willing to accept the trade-offs for what they want," he explains. “Most people don't know, for example, the ramifications of a one-story versus two-story house, from the standpoint of energy consumption or the impact of having high ceilings throughout, giving you a greater volume of indoor air to heat, cool and dehumidify."
The two-story house is more compact and, therefore, more efficient and gives the opportunity to use a central stairwell with windows at the top to create a “thermal siphon" that draws heat up and out of the house on warm days. “Even if the clients settle on a two-story plan," Pfeiffer continues, “a lot of them will say, 'We want our master bedroom downstairs.' And we say, 'If you put all your bedrooms on the second floor, not only will you save $25,000 to $50,000 on construction costs, but you'll also cut your energy bills by one-third.' Most people don't know that, and that's why good programming at the outset is so important."
After a house is finished, Pfeiffer is careful to leave the new homeowners with advice and instructions on how to gain the full benefits of green design. “We give them what we call 'the good-bye letter,' which tells them how to operate and maintain the house for maximum efficiency, comfort and healthfulness — for example, which windows to open to get good cross-ventilation and the thermal siphoning effect; how to program thermostats and other equipment; and how to maintain the house with products that have minimal effects on indoor air quality, including low-impact cleaners and low-VOC paints."
Pfeiffer's thoughtful and practical approach to green design has garnered increasing attention over the years. Numerous Barley & Pfeiffer homes have won awards, been showcased on green building tours, featured on television programs, and written about in newspaper and magazine articles. Residential Architect magazine recently selected Pfeiffer as one of the 10 “most influential" residential architects of the decade. What's the secret to his success? You might just find it printed on the back of his business card, in a quote from Henry David Thoreau: “Since most of us spend our lives doing ordinary tasks, the most important thing is to carry them out extraordinarily well." That seems to fit, like one of his well-scaled houses.
To learn more about Barley & Pfeiffer Architects, visit www.barleypfeiffer.com.