Team Massachusetts’ 4D Solar Decathlon Home is a 21st-Century Take on the Gable House

This past weekend the winners of <a href="http://inhabitat.com/solar-decathlon">2011 Solar Decathlon</a> were officially announced in Washington DC and <a href="http://inhabitat.com/university-of-maryland-watershed-house-wins-the-2011-solar-decathlon/">Team Maryland took first place</a>, however we'd also like to shine a light one of our favorite sun-powered prefabs: Team Massachusetts' <a href="http://4dhome.us/">4D Home</a>. Designed for the harsh climate of coastal New England, this elegant prefab draws from traditional <a href="http://en.wikipedia.org/wiki/Gablefront_house">gable house</a> vernacular while incorporating a 21st century set of passive and active building strategies to produce more energy than it consumes. The home features a beautiful trellis topped with 28 high-efficinency <a href="http://us.sunpowercorp.com/">SunPower photovoltaic panels</a>, a solar thermal system that provides 90% of the home's domestic hot water load, and a flexible floor plan that can easily adapt to changing family needs. Read on for an exclusive look inside!

The heart of the home's active energy generation system is a 6.4 kW array of 28 "E19 238" SunPower photovoltaic panels rated at 19.1% efficiency - that means' they're able to convert a fifth of the sun's energy in to clean electricity.

The panels are perched atop a south-facing trellis which also serves to shade the home from the brunt of the sun's heat. A set of hybrid solar thermal panels mounted immediately behind photovoltaic modules serves as a heat sink that reduces the temperature of the photovoltaics while providing 90% of the home's hot water needs.

The 4D Home's interior elements were carefully considered as well - all of the furniture, decor, and housewares were designed and built by the student team.

All of the home's appliances are ultra-efficient and energy-star certified, including a stand-by heat pump water heater and a <a href="http://www.whirlpool.com/">Whirlpool</a> refrigerator that uses less electricity each year than a 60-W lightbulb.

The floor plan central work space that serves as a buffer between the living and dining room and the more private rooms in the back.

moving wall system allows the interior to be easily reconfigured - for instance, the living and dining rooms can be expanded to host larger gatherings.

The two bedroom prefab's smart <a href="http://www.passivehouse.us/passiveHouse/PHIUSHome.html">Passive House</a> design aids the active systems by greatly reducing the need to heat and cool the interior. The home's structural system is designed to minimize <a href="http://en.wikipedia.org/wiki/Thermal_bridge">thermal bridging</a>, and the gable layout creates space for massive insulation cavities that are filled with blown-in fiberglass and <a href="http://sprayfoam.com/spps/ahpg.cfm?spgid=6">closed-cell polyurethane spray foam</a>.

s a result the home's insulation <a href="http://en.wikipedia.org/wiki/R-value_%28insulation%29">r-values</a> are exceptional: the walls are R-56, the floor is R-57, and the roof is R-64. Meanwhile, a set of triple-pane <a href="http://www.makrowin.sk/en/">Makrowin</a> windows allow daylight to flood the interior while boasting a solid rating of R-7.5.

The <a href="http://4dhome.us/">4D Home</a> beautifully blends traditional architecture with modern building techniques to create an exceptionally efficient off-grid home that can produce more energy than it consumes.

A moving wall system allows the interior to be easily reconfigured - for instance, the living and dining rooms can be expanded to host larger gatherings.

An ultra-efficient 16 SEER heat pump and a heat recovery ventilator round out the project's active strategies, providing ventilation while capturing 85% of the thermal energy from the home's air before it is circulated outside.

The 4D Home is designed to have a net negative energy balance during the cold winter months, and it is expected to produce an abundance of electricity during the summer, generating a surplus of energy each year.

This diagram shows the south elevation of team Massachusetts' 4D Home.

This diagram shows the east elevation of team Massachusetts' 4D Home.