Niche markets often emerge after serious recessions. For now, at least, the previous decade’s addiction to cheap land and poorly built, overpriced homes is giving way to a craving for modest but innovative dwellings. Enter Interface Studio Architects (ISA) and the developer Postgreen Homes, both in Philadelphia. Their 100K House, which hit the market in 2009, answers that call, while suggesting a way to design ourselves out of the housing trough. Focusing on the urban infill market, it emphasizes superior energy performance and inventive design rather than square footage—all at a price point the middle class can afford.
“We think we’re on the right track,” says ISA’s Brian Phillips, AIA. “We managed to presell 10 of these houses during the worst economy ever.” That includes two units of the Avant Garage model currently in construction—two-story, family-friendly homes above a two-car garage starting at $355,000. “Our main goal is to build homes we can sell for less than $400,000,” says Postgreen Homes founder Chad Ludeman. “Those are the homes that are moving here in this economy.”
Built for about $100 per square foot in hard costs, the LEED Platinum 100K prototype earned the distinction of USGBC LEED for Homes 2010 Project of the Year. Eight other houses have been built from that source code. Now the collaborators are developing a production line of customizable larger models with more conventional layouts and finishes, but with the same exacting energy benchmarks.
Each new project offers Postgreen a chance to tweak the pro forma for efficiencies. For example, the latest homes feature cellulose-packed, double-stud framing instead of SIPs, which are hard to crane into place on city lots. One rule hasn’t changed: To control costs and insulation values, facades are super-simple, articulated with silk screening or color patterns rather than bump-outs, though the Avant Garage exteriors “bend” so that occupants can look up and down the street.
Philadelphia was the ideal incubator for the 100K concept. The city’s population has been slowly declining for decades, though that trend has reversed itself in recent years. “Neighborhood groups are open to new ideas, because it’s been 30 years since a new idea has landed in their neighborhood,” Phillips says. It’s a familiar story. “Experimenting with how homes can be inserted sustainably is an important element of making cities work,” says John Claypool, AIA, executive director of AIA Philadelphia. “I think 100K is a wonderful demonstration of the creativity of architects.”