Like most projects heading for the 2011 Solar Decathlon in Washington, D.C., Purdue University’s INhome is designed to address regional climate conditions and cultural expectations. Purdue is located in West Lafayette, Indiana, in the west-central part of the state, where traditional-looking suburban homes with attached garages find favor among home buyers. “There’s a lot of snow up in Indiana right now,” Team Purdue’s project manager, Kevin Rodgers, told Fine Homesbuilding’s Justin Fink back in January during an interview at the International Builders’ Show. “I would love to have an attached garage.” In addition to the nod to tradition, an attached garage (which, under competition rules, doesn’t count as conditioned space), and the Indiana-referenced name of the project, IN Home’s other concession to regional preference is that the building – in contrast to many other Solar Decathlon houses – is relatively deep rather than long and narrow. The aim was to make the home’s 984 sq. ft. of interior seem as spacious as possible, and to exploit the roomy feeling created by the building’s open floor design and its vaulted ceiling, with operable clerestory windows, over the living room and kitchen areas. Two bedrooms make up the bulk of the private area, and there is a centrally located bathroom connected to the home’s “wet core” of plumbing fixtures.

From the Hoosier state to the mall Rodgers does note that, as appealing as it might be to its occupants, the depth of the building does increase the challenges the team will face when it comes time to pack and ship the structure to the National Mall in Washington, D.C. The building breaks up into four somewhat bulky shipping components: one for the living room, one for the kitchen and bathroom areas (including the wet core), one for the two bedrooms, and one for the garage. “It’s tougher to transport,” Rodgers says, “but I think it’s better for livability.” Team Purdue’s path to the Solar Decathlon began in mid-2009, when students in the school’s Mechanical Engineering Technology department began researching the Department of Energy’s competition requirements. By fall 2009, the university had created an independent study course whose students were charged with developing a Solar Decathlon proposal. Their success at that task has helped make Team Purdue the first team from Indiana to qualify for the competition and, obviously, has brought it to within six months of showing off what Rodgers says will be a remarkably comfortable net-zero-energy dwelling.

Leaning hard on PV INhome will rely entirely on passive features and photovoltaics for its energy needs. Power derived from an 8-kW array on the front, south-facing roof will be supplemented by a smaller, steeply angled array of bifacial PV panels mounted over a reflective surface on the back roof. Triple-glazed windows, made by Kolbe & Kolbe Millwork of Wausau, Wisconsin, will be used throughout, with solar heat-gain coefficients that vary by orientation. The house will be equipped with an energy-recovery ventilator. In mild weather, the clerestory windows can be opened to increase ventilation, and a trellis overhang that will be mounted near the large windows on the front of the house is designed to shade them during the summer months. Rodgers tells GBA that INhome’s shell will be constructed of structural insulated panels to R-24 on the exterior walls and R-50 on the roof. The panels are being made by Thermocore, based in Mooresville, Indiana. The project’s airtightness goal, Rodgers adds, is 1 air change per hour at 50 Pascals pressure difference. Once the Solar Decathlon is over, INhome will be shipped back to West Lafayette, although its future beyond that is still being worked out. “We’re not going to scrap the house at all,” Rodgers says. “We’re looking at a few organizations, possibly donating the home. But the goal is to look at it long term, see how we did with the design and performance, and wrap it up with some master’s theses and dissertations.”