Builders get aggressive in constructing passive houses

THE ASSOCIATED PRESSPassive homes in Philadelphia are designed to create nearly as much energy as they consume.
The Associated Press


So-called passive houses, which have been around in Europe but never really caught on in the United States, are built around the idea of making houses airtight, superinsulated and energy efficient.

The goal: a house that creates nearly as much energy as it consumes. Think of being able to keep your house warm without a traditional big furnace, and cool with no air conditioning unit.


Signature features often include thick outside walls and roofs, highly insulated windows and frames, and a south-facing orientation. The ventilation system pulls in fresh outdoor air and pumps out stale indoor air, but not before it's used to heat or cool the incoming air to the same temperature.

Houses built this way can stay comfortable using 90 percent less energy than traditionally constructed homes, according to the Passive House Institute US, an Illinois-based certification, research and consulting group.

Though the idea was born in the U.S., the roughly 20,000 internationally certified passive houses worldwide are in Europe, predominantly Germany, Austria and Scandinavia. Fewer than 100 exist in the U.S., but that's changing, from chilly New England to toasty Arizona to muggy Baton Rouge, Louisiana, said Katrin Klingenberg, Passive House Institute US co-founder and executive director.

"People associate the passive house movement with Europe, but it comes out of the (American) oil embargo and energy crisis in the 1970s," she said. "Then political change happened, (energy) prices came down but in Europe that didn't happen, so they had reason to continue the research."

The shift was symbolized most clearly, perhaps, at the White House, when solar panels installed in 1979 during President Jimmy Carter's tenure were removed in 1986 under President Ronald Reagan's administration. The Obama administration promised in 2010 to put them back but has not yet.

Making the old new

Going passive isn't solely the realm of new construction, either.


"There's a whole movement," said Torres Moskovitz, author of the new "The Greenest Home" (Princeton Architectural Press, 2013) on superinsulated and passive house design. "It's a hotbed in Brooklyn of doing these retrofits."

McDonald's firm, Onion Flats, first tackled a three-home, low-income housing development completed last fall, Pennsylvania's first to be certified under guidelines set by the International Passive House Institute, based in Germany.

The stylish, 1,900-square-foot Bellfield Homes in North Philadelphia have a heating and cooling system one-eighth the size of what similar traditionally built homes require, because they were built with an "airtight, superinsulated thermal envelope" that helps reduce energy use by 90 percent, McDonald said.

"Some passive houses are complex, but we took on the idea that we could do it with everyday construction," he said.


Will they work here?


The Stables homes are selling for about $700,000: That's for a 2,500-square-foot luxury townhouse with four bedrooms, three baths, garage, garden, and energy-savvy bells and whistles like solar panels, green roofs and airtight construction. McDonald said the price is comparable to nonpassive homes with similar amenities, in part because of cost savings from prefabricating the homes in modular sections and assembling them on-site.


Sasha Best, her husband, and their 2- and 6-year-olds were moving from Manhattan's financial district into one of The Stables townhouses in late June. After living for a year in a high-efficiency home in Germany, they returned last year to New York, where Hurricane Sandy's destructive tear led them to rethink where they wanted to call home.



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