Little Samples of Solar's Future

A design by Germany's Technische Universitat Darmstadt won the Department of Energy's Solar Decathlon, which judged 20 prototype solar-powered houses. (By Elizabeth Razzi -- The Washington Post)

"It's getting more streamlined to where it's more aesthetically pleasing from a curb appeal standpoint," he said.

Callahan said he expects consumers to be receptive to solar-power features as they realize that the lower living expenses will offset some of the technology's cost. "As more adopt the technology, the price will come down to where it will be mainstream."

While solar energy would be feasible in a large house, the prototypes on the Mall were restricted to about 800 square feet, about one-third the size of the average new home.

The ones I saw had one bedroom, one bathroom and not much storage space. But many were designed with the idea that other modules could be added or taken away as the occupant's needs changed.

"You can have a 3,000-square-foot house that is solar," Callahan said, "but I think homes are going to get smaller from a green standpoint." Prices might drive the move toward smaller homes, too, according to Callahan.

There are a lot of buyers in the Washington area who would welcome smaller, more affordable new homes, especially if they featured the kind of design innovations on display during the decathlon.

Some of the houses had beautiful interior finishes, such as slate floors with radiant heat, tiled shower stalls, granite countertops and large, well-insulated windows. Interior spaces were flexible. In the German house, for example, a kitchen counter/table could be slid over the food preparation counter when the meal is done, freeing the space for other uses. Even the bed disappeared into a cutout in the floor. (I don't see the attraction of burying the bed, but nevertheless, it offers versatility in a small space.)

In the home built by Penn State University, my alma mater, a wall-sized cabinet separating the dining area and the bedroom could be moved on tracks, allowing the occupant to decide which room needed more space at the moment. This is practical stuff that could allow people to live comfortably in smaller spaces right now.

Many of the prototypes had a feature often overlooked in new-home developments: a small, private outdoor space where people could enjoy fresh air and maybe cultivate a little garden, if only in containers. It would be heartening to see more houses built with well-planned and landscaped courtyards, patios and outdoor niches such as those incorporated in the solar homes.

On the dry, dusty Mall, in the shadow of the Washington Monument, these small outdoor gardens, some irrigated with rain collected from the roof, felt like a refuge. New homes could use more of these affordable, human-sensitive design features now, while we wait for solar technologies to become more versatile and affordable.

E-mail Elizabeth Razzi atrazzie@washpost.com.