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Developing experimental systems, using untried products and materials, and feeding loads of surplus solar energy back into the electrical grid were not the goals of the University of Wisconsin-Milwaukee's Solar Decathlon team. Instead, the students focused on designing and building a modest solar-powered house that demonstrates affordable solutions for an average Wisconsin family. Nearly every major system in the house is off-the-shelf.

"We didn't modify anything," says master’s candidate and team project manager Eric Harrmann, also an architectural intern with senior living design firm AG Architecture in Wauwatosa, Wis. "Part of our approach was to use pieces that any Wisconsin homeowner could purchase and use easily." In fact, all the products and systems tie into the team's regional approach.

The Meltwater house draws its design inspiration from Milwaukee's Menomonee Valley, from an exterior form that echoes the valley's glacially-sculpted topography to its modest size and price and conservative use of technology. Steaming and shaping reclaimed pine donated by the Aldo Leopold Foundation, the Meltwater team translated the area's topographical characteristics into a uniquely beautiful exterior rainscreen cladding that undulates across the surfaces of the house. Reclaimed pine also was milled into window frames and sashes.

Though modesty and off-the-shelf selections were the team's modus operandi, the members didn't altogether reject innovative use of materials. Meltwater's kitchen countertops and tabletop surfaces are Paperstone—a common enough use these days—but the team also worked with a window manufacturer to develop the first Paperstone window, which is installed over the kitchen sink.

With the help of Fat Spaniel Technologies, the team also developed a home energy monitoring system with a Web interface that displays the house's energy production and use, accessible from any location.

Meltwater's butterfly roof helps camouflage the 5.6-kW photovoltaic array, keeping the overall aesthetic modern but not "techy." While most of the competition homes were intent on generating enough surplus electricity to feed back into the grid, the Meltwater team decided only to generate as much energy as the house requires to operate.

"We're teetering close to the neutral point," Harrmann acknowledges. "While some teams will be delivering energy to the grid, they spent a lot on their PV array. We decided to go smaller and use more efficient products."

Solar thermal collectors provide hot water, while the butterfly roof  funnels rainwater and snowmelt to a collection pond that spills into a deck garden.

Comfort as well as energy efficiency are major features of the Meltwater concept. The modular house has an 8-inch-thick wall cavity built using a staggered 2x4 construction and sealed with spray polyurethane foam to provide a continuous insulating barrier for both sound attenuation and energy efficiency.

While Meltwater's footprint is only 724 square feet, its interior layout provides plenty of livable space in which to move and entertain, especially when its flexible features are activated, opening up additional usable space. Riffing on the Murphy bed in Meltwater's bedroom, the team designed and built an eight-person dining room table that folds down from the wall. Its placement adjacent to the house's west-wall telescoping glass door expands the dining and entertainment space to the deck when the door is open.

To extend the small, one-wall kitchen area, the team  created a fold-away island on an L-shaped base made of the same laminated bamboo material as the kitchen cabinetry. Its two counter surfaces hinge up and lock in place to give 10 additional square feet of workspace.

The bedroom also incorporates flexible components; not just a Murphy bed and built-in storage, but a gliding armoire system along the semi-open wall shared with the living room's entertainment center. Sliding the armoire components open gives a clear view of the entertainment center's television console, which can be rotated to face the bed; sliding the components closed cuts off the view and provides more privacy.

The 12-foot-wide-by-7-foot-tall telescoping glass door, situated to frame valley views back at Meltwater's site in Milwaukee, is an architectural feature that could have detracted from the house's performance. To deflect excessive heat gain through this wall of glass, the team included an automated louver system that tracks the sun's movement throughout the day, preserving both performance and beautiful views.

Stephani Miller is Associate Web Editor for residential architect and Custom Home magazines.