University of Illinois at Urbana-Champaign—Illinois' Gable Home reflects the vernacular agricultural structures of the American Midwest and uses reclaimed barn wood for its cladding and decking. Designed to meet Passive House standards, the Gable Home maintains a comfortable and consistent interior climate.

University of Kentucky—Kentucky's blue house is a fully ADA-compliant home that references the Kentucky vernacular and incorporates local materials integrated with modern energy-efficient systems and technologies. Centered around a kitchen core, the house engages its landscape through a series of outdoor rooms that wrap the structure.

University of Louisiana at Lafayette—The Louisiana team's BeauSoleil Home is designed as a dogtrot house that responds to the local culture and climate to provide a prototype for affordable replication. Constructed of structural insulated panels, the house uses both passive and active systems to achieve performance goals, including photovoltaics, solar thermal for water heating, and high-efficiency mechanicals, appliances, and lighting. BeauSoleil harvests rainwater for use in the home.

University of Minnesota—Minnesota's ICON house works with the daily and yearly cycles of nature to provide a comfortable and modern living environment. The house uses passive solar design and daylighting, as well as photovoltaic arrays integrated into its gabled roof and porch to conserve, harvest, and produce energy. Solar thermal collectors heat water, and a dessicant system uses extra hot water produced in the summer to dehumidify the house.

University of Wisconsin-Milwaukee— Designed as an ancillary unit to an existing house, the UWM team's Meltwater house allows an empty-nester couple to live on their children's property while maintaining a separate home. In addition to photovoltaics and solar thermal systems, Meltwater incorporates automatically adjusting louvers along its west-facing doors to reduce solar heat gain; louvers above the south-facing clerestory windows protect against heat gain in the summer, while allowing heat gain in the winter.

Virginia Polytechnic Institute—Virginia Tech's LUMENHAUS maximizes exposure to natural light. It incorporates several solar strategies, including the Eclipsis System, an automated collection of independently sliding exterior layers that filters light throughout the day; in the winter, the system opens up to allow the concrete slab floor to harvest solar energy, which heats the house. Energy collected during the day is used to power an LED lighting system embedded in the Eclipsis System's insulating panels.

Many of the teams are tracking their construction progress on their websites. Stay tuned for more coverage on the 2009 Solar Decathlon.

For ra's coverage of the 2007 competition, click here.