It's easy enough to slap solar panels onto a roof, but integrating them into a graceful residential design is a tougher assignment. Such was the challenge for 18 university teams competing in the second biennial Solar Decathlon, held recently in Washington, D.C., and sponsored by the Department of Energy and the AIA, among others. The students vied to design, build, and operate the most attractive and energy-efficient solar-powered home.

The University of Colorado won the overall competition, which conferred points in 10 categories, including power generation for heating and cooling. Virginia Tech took first place in the architecture and dwelling categories, which emphasize aesthetic achievement and the comfort of occupants. “Everything about this house is wonderful,” said jury member Sarah Susanka, FAIA. “It took my breath away.”

Virginia Tech's house uses operable windows and shading devices rather than mechanical equipment for heating, cooling, and lighting. South, east, and west walls are polycarbonate panels filled with aerogel insulation. Clerestory windows admit daylight, while movable dampers in the walls bring in fresh air. Motorized shades adjust temperature in the wall cavity during the day and offer privacy at night. The inverted roof conceals the solar panels and conveys rain into a cistern for gray water use.

California Polytechnic State University, which placed second in the architecture category, designed its house with structural insulated panels and colored fiber-resin cladding. The designers kept the house narrow for easy transport and added solar panels, awnings, and a rooftop deck on site. The judges called the exterior “beautiful” and the interior “elegant.”