March 23, 2010
Passive Aggressive in Rainier Valley
Seattle’s getting more aggressive about “passive” home construction. The first-ever passive house in the state is under construction right now in Rainier Valley. There, on a lot sandwiched between a Safeway and his own house, Dan Whitmore is applying “passive” principles to a 2,500-square foot home. While the site looks pretty much like every other under-construction home you’ve ever seen, Whitmore’s work is different in this respect: The new house promises 80 percent more energy efficiency than current Washington building standards and even more efficiency than many “certified” green properties.
“A passive house fulfills a particular energy standard,” says Whitmore, who grew up in a passive house in Oklahoma during the 1970s. “It’s not a prescriptive look or way of building.”
Properties that qualify as “passive” draw minimal energy from the local grid and use design techniques to preserve energy consumption to achieve an indelibly light footprint. It’s different than the more well-known approach of building sustainable homes that rely on alternative energy. Passive homes simply use energy more efficiently.
As Whitmore puts it: Unlike a “net zero” home which uses renewable energy sources sufficient or excessive for its inhabitants’ energy needs, a passive home’s ambitions are focused less on self-generation of energy than efficient, conservative use of it. Pac Northwest builders are taking notice, undertaking grassroots projects to familiarize themselves with the practice. They’re convening this Friday in Olympia for a powwow on all things passive construction as well as at local meet-up groups in Portland and Seattle.
And local filmmakers have made Whitmore’s build its subject for a forthcoming documentary called “The House that Saved the World.” Nathan House (yes, his real name), one of the project’s creators, says he and others involve plan to pitch the show to public TV execs within the next six weeks.
Whitmore isn’t the only local builder working on prototype properties: Joe Giampietro, an architect and director of the housing practice at Johnson Braund Design Group in Seattle, developed a 300-square foot cottage design last year known as the Mini-B Passive House (the “Mini-B” stands for mini-bungalow), which community college students are currently building as a woodshop project through Seattle Central Community College, he says. Giampietro envisions eventually partnering with a modular builder so that the cottages can be sold, probably for $75,000 to $100,000, to homeowners interested in an accessory unit or property owners seeking an environmentally gentle vacation home.
So why the enthusiasm for passive in passive-aggressive Puget Sound? Passive building standards have been around awhile—just check out the Passive Haus Institut in Darmstadt, Germany, where it all began, or the U.S. enthusiasts’ site. But adoption in the U.S. has taken longer than in Europe, where it’s estimated that at least 15,000 properties live up to passive energy standards.
During a visit to Whitmore’s site last weekend, he told us how his new home will fulfill the passive checklist. Passive structures require three major components, he notes. First off, they should consume less than 4.5 kilowatt hours per square foot per year to heat and cool. Secondly, the whole structure’s energy usage (i.e. appliances) shouldn’t exceed 38 kilowatt hours per square foot per year. Finally, the home should be super-duper airtight—meaning it’s hyper-insulated against energy-wasting air leaks, experiencing just 0.6 “air exchanges” per hour, versus an old home’s ten exchanges, recent construction’s four to seven, or a “very tight” home’s 1.5 exchanges.
In practice, passive homes often have very thick walls—15-inch, versus six-inch in Whitmore’s case—as well as lots of insulation and a high-tech fan that modifies air cleanliness, given how airtight the home is. They also must include energy-efficient appliances, by necessity, but commonly-available Energy Star or other mainstreamed energy-efficient brands suffice, Whitmore says. Whiz-bang green materials aren’t necessarily the point of the project. Whitmore says that, with only a few exceptions, he’s using conventional building materials. One quirk: The home is technically 2,500 square feet, but offers only 2,200 square feet in terms of living space due to the walls’ thickness.
Others in the industry wonder whether passive house or LEED standards are better for builders to follow as they pursue the holy grail of energy-efficient building—or whether some melding of the standards might make for the total ultimate green home.
Last month, Monique Lee Hawthorne, an associate in Portland with Davis Wright Tremaine—and, objectivity alert: the spouse of a passive house project leader—discussed standards in an Oregon Daily Journal of Commerce column, noting that, on an energy basis alone, passive house standards rock the house when it comes to energy savings.
Whether passive houses and cottages will start proliferating landscape, or appear on a public TV station near you, is another matter. Architects and builders, it seems, are still learning the process.
“We should probably have our heads examined,” says House, the documentary creator. “We’re sharing what actually goes on during a build, not just the before and after.”