The Solar Decathlon took place in early October in spite of the government shutdown that furloughed all but the most essential employees at the U.S. Department of Energy (DOE), which organizes the biennial competition. Fortunately, the decathlon was funded during the previous fiscal year and is also supported by private donors. But there was another reason the fiscal battle in Congress barely cast a shadow over the proceedings: For the first time since its founding in 2002, the decathlon wasn’t held on the National Mall in Washington, D.C., but rather at the Orange County Great Park in Irvine, Calif.

Much as in the 2011 competition, judges evaluated the entries not only for their energy efficiency, design, and affordability, but also for their livability. Which is why students mock-inhabited the houses: cooking, doing laundry, and washing dishes. In that respect, the decathlon reinforces the values of domestic life and the American Dream of the single-family home. So it may come as a surprise that two of the three top overall finishers hailed from Europe—first-place Team Austria and third- place Czech Republic—with projects that, in this context, challenged the conventions of typical United States housing.

Team Austria’s entry, named LISI, was a joint project by Vienna University of Technology, St. Pölten University of Applied Sciences, Salzburg University of Applied Sciences, and the Austrian Institute of Technology. With large retractable sliding glass doors by the manufacturer Josko on the north and south sides, the house opens itself up to the elements, taking advantage of passive cooling. With all of the living functions contained in one big room instead of being subdivided, the interior feels like a covered exterior courtyard. The bedroom, by contrast, is tiny—a cave-like, wood-lined room.

The Czech Technical University’s AIR House is similar to the Austrian entry: A single loft-like space with a sliding door that opens directly onto an outdoor living room. It’s an L-shaped structure shrouded in a wood canopy and façade: a “house within a house” according to the team. The main living space is located in the long leg of the L, and the short leg houses the bathroom and equipment for the radiant chilled ceiling system, rooftop solar panels, and graywater collection system. The house is marketed not to first-time homeowners but to empty nesters as a vacation retreat that can be transformed into a retirement home.

Comfortable and livable, AIR House and LISI are far from radical. (For radical, check out DALE house, the SCI-Arc and Caltech entry that was composed of two modules on railroad tracks that could be motored open and closed for ventilation.) But the Austrian and Czech entries are a departure from the more conventional designs proposed by many of the North American teams. Both the Czechs and Austrians maximized single living areas and minimized auxiliary rooms, which streamlines passive heating and natural ventilation. And typical of the European climate, both designs are more concerned with heating than they are with cooling. Heating demands for LISI in Vienna are 9.7 kWh/m per year and cooling is 5.6 kWh/m per year. In sunny Irvine, the loads skew much more to cooling—10.6 kWh/m per year—while heating is 2.7 kWh/m per year.

By comparison, consider DesertSol, the entry from the University of Nevada, Las Vegas (UNLV), which finished second overall in the competition. You can’t argue with the house’s strong metered-energy performance. Like all 19 teams, UNLV scored a perfect 100 out of 100 for the Energy Balance Contest—meaning that solar energy production exceeded the house’s total consumption. DesertSol splits into two modules of roughly equal size: one for living and dining and another for sleeping and bathing, with a large shade structure over the back of the house. Neither space feels particularly generous. And like many entries, there was a tendency to partition functions and program areas rather than explore how they might come together in new ways.

That conservative approach may be tied to construction. The UNLV entry employs factory- built modules, each mounted on an axle and chassis, so manufacturing criteria and towing regulations set the building’s proportions. Although the modular design allows for quick site construction and a lighter impact on the ground, the house does depend on the use of fossil fuels for delivery and would mean new housing stock on virgin land in Nevada, an area hit hard by the financial crisis. According to research firm RealtyTrac, the state had the highest foreclosure rate in the country in August, with one in every 359 housing units filing. It would seem that retrofits, rather than new construction, would ultimately be a more responsible and holistically sustainable option for Las Vegas. Or even in Irvine, for that matter.

All of these specific issues raise a larger question about just how effective the decathlon is at advancing the message of sustainability. Founded as the real estate bubble was starting a decade ago, the competition remains beholden to the notion that the single-family house is the best vehicle to reach homeowners and mentor the next generation of designers.

Moving the competition from the Mall to suburbia only underscores this continued disjunction between ethos and actuality. The Orange County Great Park occupies the site of the former Marine Corps Air Station El Toro, and its master plan was designed by New York–based landscape architect Ken Smith. The park is only half-finished. Construction stalled because the developer FivePoint Communities “shelved plans for building the thousands of homes that were supposed to surround the park and generate tax money to fuel its growth,” the Los Angeles Times reported last year. To add insult to injury, the state government seized the property taxes that were supposed to fund the project in order to offset California’s massive deficit.

All of which is to say that the Solar Decathlon demonstration homes built by this year’s bright and creative students were staged at a site where a similar model of homeownership had failed. (In late October, FivePoint floated plans to finance and build much of the park if the city allows it to almost double the number of houses it can construct on the site, to a total of 9,500.)

However that proposal plays out, the lessons of green building need to address more typically urban issues: multi-unit and multi- generational housing, transportation, and infrastructure. The house is rapidly becoming a luxury item, and cities like New York and San Francisco are experimenting with microunits. Los Angeles, meanwhile, just an hour drive from Irvine, was listed in the most recent census as the densest city in the U.S.

For real innovation to occur, the DOE should revamp the 2015 decathlon to address more than energy loads and curb appeal. In terms of sustainability, the conventional single-family house, even a solar one, may have already had its day in the sun.