From the outset, affordability played a major role in every decision the Empowerhouse team made, especially because they were building this home for Habitat — they wanted the model to be able to be replicated. The house cost just $229,000 to build, meaning that the team won full points for affordability and took first place in that category. But this figure includes the cost of labor, so when it’s built by Habitat, the cost of the house is likely to be halved because Habitat uses volunteers.
The team did all of the work themselves, and once it is complete, Empowerhouse will be tested and (hopefully!) certified to Passive House standards. When the Decathlon ends at the end of the week, the house will be moved just ten miles away to D.C’s Deanwood neighborhood, where it will be expanded into a two-story duplex for two local families.
“We wanted to build a house specifically for a site,” said Stevens alum Stephen Scribner, the Project Manager for Empowerhouse. “We didn’t want to ship a house to D.C., then ship it somewhere else.”
To that, Empowerhouse is built specifically for D.C.’s humid climate, and the team carefully considered the environmental impact that the house will have on its Deanwood site. Because it is built to Passive House standards, the home will consume 90 percent less energy than a traditionally built home of the same size. Its photovoltaic array, just 4.2kW, is one of the smallest in the competition, yet it still produces all of the energy needed to heat and cool the home. The home’s HVAC system requires only the amount of energy needed to power a hairdryer.
Since Passive House is all about superior insulation, Empowerhouse used 12-inch wooden I-joists for the walls, which created large cavities that were filled with dense pack cellulose insulation. I-joists aren’t usually used for walls because it is costlier, but it is a more stable and better insulated method. Empowerhouse also taped every single window, wall, and door seam in the house to ensure the best possible insulation, a process that Habitat now does for all of its homes.
Because Empowerhouse is being built for a specific site, the team had to make some adjustments that will likely cost them in the competition. To optimize solar heat gain, a home’s largest side should be open and south facing, but because of the shape of the Deanwood site, Empowerhouse could not be oriented like this. To make up for it, the smaller south facing wall has large windows, and a loft area, which will be the stairs to the second floor, is open to let natural light flow inside.
But the Empowerhouse team made it clear that the Solar Decathlon is “just a pit stop. It’s just to show it off,” said Scribner. Within a month, the team should have all the necessary permits secured to begin construction on the Deanwood site. The team actually had the pleasure of meeting one of the family’s who will be living in Empowerhouse. Photos of the family line the shelves of the house on the National Mall, already making it feel more like a home rather than just an exhibition.
All images © Jessica Dailey for Inhabitat, unless noted