The Solar Decathlon felt like a small Olympic village today as team members from Canada, New Zealand, Belgium, China and the US hustled to finish their houses by Tuesday evening. Wearing Red Wing boots, I trudged the 1.3 miles from the Smithsonian Metro station to West Potomac Park. Because the nineteen small structures are still under construction, visitors were required to wear hard-soled boots, long trousers, a shirt with sleeves, safety glasses and a hardhat.

Wednesday is a media day, and Thursday is a media and VIP day, but the houses will be ready for public viewing starting on Friday, Sept 23rd and ending the following Sunday, Oct 2nd. DOE will be running free shuttle buses every fifteen minutes from the Smithsonian Metro, so visitors won't have to walk. Charlotte, one of the DOE's media representatives, met me at the media trailer. After introductions, she asked if I had read yesterday's NY Times article on one of the houses. I hadn't, but the article did reflect a different tone for this year's competition, one expressed by several team reps:

This year, for the first time, houses in the competition are being graded on cost-effectiveness, [they call it Affordability] as well as energy efficiency and attractiveness. The last winning house was a $2 million entry from Germany with an exterior completely covered in solar panels.

“They racked up extra points because they were producing power above and beyond what the house needed,” said Joshua Laryea, student project engineer from Stevens. “But who can afford a house like that and maintain all those solar panels? It wasn’t a place designed for living in.”

Joel Towers, the executive dean at Parsons, said: “... a lot of the technology that’s needed for tomorrow’s housing is already available. The question we’re trying to answer is more social than technological — how do we actually bring these green solutions into neighborhoods?”

I knew I couldn't see everything in two or three hours, but we started at the North end and worked our way South.



Team New Zealand's house, First Light, was clad in horizontal cedar boards, flush not lapped, colors ranging from almost yellow to brown. A delicate lattice brise-soleil of pinus radiata extended over the flat roof and obscured the rooftop array of collectors. Charlotte introduced me to Nick, who explained that First Light was inspired by the Kiwi bach (pronounced batch), a traditional open air holiday home, where New Zealanders retreat and socialize during summer months. So they have attempted to provide social spaces open to the outdoors. A Kiwi fellow in my office said 'bach' may be short for 'bachelor', and that such shacks are also known as 'cribs' in south NZ.

Nick showed me the "Shed," a utility closet containing the various heaters, exchangers and monitors that can make any house more efficient. But First Light was also designed as a Passive House. A blower door test rated it as the second most air tight structure in New Zealand. For cavity insulation they used 240mm (about 9 inches) of New Zealand sheep's wool recycled from old carpeting. First Light used triple-glazed windows, custom fabricated in NZ. Nick seemed proud of their drying closet, which uses hot water piped from the roof. I asked about the team. Nick cited 26 team members studying architecture, landscape architecture, interior architecture, marketing and building science at Victoria University in Wellington.

Once inside, Nick pointed out a large concrete table that would serve as a thermal mass. He pointed out the skylights and reemphasized their goal of connecting to the outside. He mentioned differentiating served and service space, and public from private space as well. Such goals, or concepts, are important to architects as generators of design. During critiques, designers will be asked why they made certain choices. They strive to give a reason based on program, constraints or goals. "They had a reason for everything," is a supreme compliment, and it seems that Team NZ did have a clear idea of what they hoped to accomplish.


Team Tidewater designed Unit 6 as an urban house for an arts-and-crafts neighborhood in Norfolk VA. Where NZ's goal was to connect with the great outdoors, Tidewater's goal was to maintain interaction with the strong street culture. To that end, they designed a "sunspace" area, with a large operable window, that can function as a porch in warm weather, but that can act as a passive heat sink space in winter. The siding was MDO plywood with vertical battens superimposed with clear-finished cypress trim emulating arts-and-crafts detailing. Gayko, a German company, provided dual-tilt windows that opened as both hoppers and casements. They were painting inside, so we didn't get the interior tour and then Decathlon officials needed the team leaders for a water test, so we moved on.



Team New Jersey's spokesman admitted that everyone thinks their concrete eNJoy  house looks a bit like Corbu's chapel in Ronchamp. The often-perforated walls are a sandwich of three inches concrete, six inches insulation and three inches concrete, with a rough surface outside and a smooth surface inside. So the house weighs about half a million pounds. The roof is an inverted concrete hip which both catches rainwater and allows the panels to face South on a North-facing site. Lighting and utilities were recessed in the concrete, so furring was not required. eNJoy used Serious windows, from California. The team's site claims that the concrete wall will act as a thermal mass, "Concrete's thermal inertia allows walls and floors to be warmed by the sun during the day and radiate heat into the space throughout the night," but I wonder if  6" of insulation will allow heat into the space.

Next was Empowerhouse, which had been profiled by the New York Times.

The compact, shoe-box-shaped mystery building is named Empowerhouse, and it is a superefficient, solar-powered house that will compete in the Solar Decathlon, an event sponsored by the Energy Department that will open on Friday on the National Mall in Washington. It was designed and built by architecture and engineering students from Parsons The New School for Design, the Stevens Institute of Technology and the Milano School of International Affairs, Management and Urban Policy.

Yet the group aimed to create a structure that would endure in a meaningful way after the competition results are in. Unlike the 19 other entries, Empowerhouse is destined to become a real home for a low-income family in the Deanwood neighborhood of Northeast Washington that will also serve as a model of sustainable housing for Habitat for Humanity.

Empowerhouse tackles cost-effectiveness through “passive house” design principles, an international standard to minimize energy demand that is just beginning to gain traction in the United States. Passive houses are well insulated and nearly airtight, with 12-inch walls and triple-glazed windows, and they require up to 90 percent less energy for heating and cooling than an ordinary house. (They consume 40 percent less than a typical high-efficiency home.)

The team leader explained that because they had a real site, Empowerhouse faced the real world challenge of being oriented to the road with the short walls facing North and South. Their walls were framed with Nordic IJoists - essentially an I beam made of laminated wood. I've used similar products as floor and roof joists, but never in walls. But the narrow OSB web wouldn't tend to conduct much heat through the walls. Nordic, he claims, is known for excellent forestry management. Their laminated wood uses young growth 1 x 1 laminations instead of microlaminations with lots of glue or thicker components of older forest wood. Their glazing supplier, Intus windows, seems to be a US company selling windows made with German and Austrian components.

Tennessee's Living Light house was clad in what looked almost like dark cabinet wood. Team member Lauren said it was a rainscreen system of composite wood panels by Prodema. She said the plan - wide open in the middle with kitchen at one end and bathroom at the other - was inspired by Appalachian barns, although the website shows a lot of other sources as well. For the double glazing/ ventilation scheme (shown above) they used Kawneer, one of the few American window manufacturers I've encountered here. Their rooftop collectors were by Solyndra, which I've heard of somewhere...



I spoke with Melissa and a young man from Middlebury College, certainly better-known as a liberal arts school than a technical powerhouse. Their Self-Reliance concept derives from Emerson's essay of the same name, and there didn't seem to be any foolish consistencies in the design. Middlebury does not offer a professional architecture degree, but they do offer programs in Architectural Studies, "The focused study of architecture as a humanistic endeavor," and Architecture and the Environment. On the outside the house looks like a black-stained full Cape with a large window in the center instead of a door. Louvers on a barn door track allow additional shading of that large window, and metal shelves inside allow for an interior garden behind it. For shipping, they broke up the lower house longitudinally but the roof transversely to avoid having a prominent ridge beam. High ceilings with exposed roof trusses tie the interior scheme together. Much of the flooring is black Vermont slate tiles. The assembly photo from their blog gives an idea of the thickness of the roof insulation in a passive house.



McKenna explained Purdue's INhome project (INdiana home). Purdue is another school that doesn't offer a professional architecture degree, so the team was made up of landscape architects, industrial designers, engineers, etc. McKenna, a communications management major, said the home was designed by committee and only smiled when I told her that, "designed by committee" was a common insult. In truth, most buildings are designed by some sort of team these days. INhome looks more like a contemporary suburban house than anything I've seen at the decathlon. It has a comparatively large bathroom and even has a garage. But McKenna feels that the house is practical, reassuring and reflects Midwestern consumer values. And she had a reason for most everything as well.



Dave Lee showed me the Appalachian State Solar Homestead house. He said this was the only entry to have been designed without architects or engineers at all. The Homestead features a large breezeway, roofed with solar panels that absorb energy from top and bottom. On one side of the breezeway are unheated closets and a study/guest cottage. The main house is clad in vertical boards with accents of tree bark and galvanized corrugated metal. It was also a seriously passive house.

There are of course about ten more houses I didn't tour, but I hope this gives readers an idea of what is going on there.

Update - Charlotte emailed me info on food facilities:

There will be a food tent onsite for the duration of the Solar Decathlon.  I believe it’s scheduled to be in West Potomac Park on Tuesday, 9/20 (11-1pm), Wednesday, 9/21 (11-1pm), and Thursday, 9/22 (11am-3pm).  Once the solar village is open to the public, the food tent will be open during all public hours, which means weekdays (10am-2pm) and weekends (10am-5:30pm).

And there are clean, "jiffy johns" on site now - even in ADA accessible sizes. Or you could walk to more permanent Park Service facilities near the FDR, MLK or Jefferson Memorial sites.