Autonomy lesson
Thursday, May 20, 2004
Randy Gragg
The Oregonian
A high-performance home produces its own energy—and has some to spare
Oregon’s first “zero-energy” home—a house that produces more energy than it consumes—is all about connections, the first ones made around the dinner table.
Marie Taylor was worried that her parents someday might not be able to climb the 46 steps to their Eugene home. So she and husband Taylor Watkins asked if they might like to move into what the city of Portland officially calls an accessory dwelling unit, informally known as a granny flat, in their back yard.
The short answer for her parents, Eldon and Linda Rose, was “yes.” The longer answer is now rising on Taylor and Watkins’ one-acre Northeast Portland lot. Set to be finished just in time for a tour during the American Solar Energy Society’s national conference in July, the now half-finished house also will be open Saturday for a tour sponsored by Portland’s Office of Sustainable Development.
The house will feature a smorgasbord of energy gadgets: a solar heat pump, 270 square feet of electricity-producing photovoltaic panels, along with energy-recovery ventilators that recycle already-heated air.
If all goes as planned, the Roses’ electrical meter will tick backward as much as forward as it produces as much electricity as it consumes, costing the semiretired couple nothing to light, heat or cool.
The house is also a simple but inspired work of architecture being built with studied care by noted green-building contractor Coho Construction. From the thickly insulated roof to the mostly tiny windows the energy demands allow, every detail has been used to maximum aesthetic effect—all for around $125 per square foot.
It was all in the connections, Eldon Rose explains. His daughter and her husband knew architect Clark Brockman. Having just returned from a yearlong Asian bicycling trip, Brockman volunteered to design the house for a cut-rate fee. But the Roses also had an old friend they’d met on one of their Peace Corps trips to American Samoa: Christopher Dymond, an analyst with the Oregon Department of Energy.
And so the house began.
Brockman soon went back to work, for green-conscious SERA Architects. The firm immediately saw the research and marketing potential in designing a zero-energy home and allowed its new employee to devote his time to the project pro bono.
SERA wanted to prove two things, according to the firm’s design chief, John Echlin: You don’t have to be wealthy to build a high-performance home; and a sustainable house can be interesting architecturally.
“They always come out of the textbooks looking like engines,” he says, “but they need to relate to people.”
Echlin’s hope was to turn the Rose house into a contemporary update of the “Case Study Houses,” the prototypes for new kinds of social and physical architecture pioneered with famed mid-20th-century model homes designed by the likes of Charles Eames, Richard Neutra and Julius Shulman.
Meantime Dymond’s colleague Kacia Brockman, who happens to be the architect Brockman’s wife, suggested pushing not just for energy efficiency but for energy production.
With even the U.S. Geological Survey saying world oil production will begin its decline in 2016, Dymond predicts a growing network of houses that produce more power than they use as the region’s “next energy plant.”
“The U.S. Department of Energy has set a target of 2020 for net energy homes to be mainstream,” Dymond says. “Oregon will have its first one built in July. All we did was integrate already available technologies.”
Some of the innovations cost more than standard technologies. For instance, the inverter required to transform the extra electricity produced by the photovoltaics to the type of current required for the electrical grid costs upwards of $2,500.
But other energy-saving features simply require a change of materials or thinking. Instead of using tape to seal ducts, which can result in as much as a 15 percent loss in efficiency, the heating and ventilation system will be sealed with a flexible, puttylike mastic. As well, the Roses were able to dump conventional systems, most notably a furnace, in favor of the solar heat pump. Engineer a house properly, Dymond says, and you can heat it with the BTUs produced by a standard water heater.
Nevertheless, the house’s originally planned $100 per square foot budget climbed to about $125. Eldon Rose describes the upward tick ironically as “selfish,” but he adds there came a point when he decided he wanted to create a leading prototype home “for himself.”
Coho Construction’s David Heslam says prospective clients’ first question is always, “How much extra will a high-performance house cost?” The choice, he says, is “about spending money where your values are.”
“How much is the Jacuzzi or the granite counter tops?” he asks, referring to luxury options popular with today’s homeowners. “Skip one and you can afford a package that will save you 15 percent on energy costs—forever.”
With the Roses, the choices aren’t surprising. Eldon Rose co-invented and manufactured a noted self-pumping solar water-heating system in the early 1980s known as the Copper Cricket. A planetary scientist by training and longtime consultant with NASA’s Jet Propulsion Laboratory, he now is studying the seasonal atmospheric changes on Mars recorded by the Mars Odyssey orbiter. Linda Rose has five college degrees and has taught special education for the past 30 years.
The fanciest finish in the 800 square feet of the Rose house will be the imported Mexican tile in their living and dining rooms and bathroom.
“It feels so right, so integrated,” Eldon Rose says. “The space feels so large. It’s amazing how suddenly this little plot of land can feel so large as rooms.”
The house is the maximum size for an accessory dwelling unit. But the key problem, Brockman recalls, was “getting the house to fit within the energy you can make.”
As well, the group had its conflicts. Green builders wanted to use as many renewable materials as possible, Brockman explains. Energy people wanted to make it efficient. The designers wanted to make it pleasing.
So compromises were struck. The all-fiberglass-framed windows are made with some pretty harsh chemicals, but they offer the highest performance, losing only half the energy of standard vinyl windows.
Other choices converge aesthetics and energy. A clerestory window bathing the rear wall of the living room in light will satisfy Linda Rose’s urge for the closest Northwest equivalent to the tropical light of American Samoa. As well, the clerestory windows are operable. As the prevailing north-by-northwest summer winds blow over the roof, they will create negative pressure on the house’s south side, turning any open window into an outventing fan.
Internally, the wall’s studs are staggered. The 10-inch-thick east wall, for instance, is supported by 2-by-6-inch studs alternately aligned with the inside and outside surfaces. This allows for continuous insulation with no breaks for studs. By using blown-in polystyrene insulation rather than fiberglass, the Rose house will have not only better heat retention but also a better internal moisture seal, eliminating the need for the typical Tyvek external seal. Consequently, beneath the Rose house’s Hardiboard shiplap siding is nothing but old-fashioned tar-impregnated paper vapor barrier plus a 3/8-inch air gap to dissipate moisture from inside and out.
“It’s almost like industrial design,” Echlin says, “taking something so small and making it so integrated.”
But for all its energy correctness, the Rose house is also shaping up with exciting aesthetic moments. The double-height entry and living room makes the modest space seem more expansive. The thick, structurally insulated panels forming the roof give the house a crisp, clean, planar look with a Frank Lloyd Wright-style muscularity. The lap siding’s corners will be mitered and covered in metal for a crisper cut. Windows, such as the 6-foot-tall vertical one over the kitchen sink, offer function but are played to maximum architectural effect.
How well will the house work? Stay tuned via some more connections: The Oregon Institute of Technology is wiring the entire house with 49 sensors in the walls, roof and foundation to measure everything from heat gain and loss to dew point. The data will be transmitted via cable modem.
(In accordance with Title 17 U.S.C. Section 107, this material is distributed without profit to those who have expressed a prior interest in receiving the included information for research and educational purposes.)
Posted by: noble on May 21, 2004 at 13:26:17