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Unity College is in the throes of a deep cold snap when first-year student Jamie Nemecek walks into a classroom for a lesson on sustainable home design.
The classroom is the home of college president Mitch Thomashow; it’s designed to generate more electricity than it uses, thanks partly to deep insulation and passive-solar architecture.
“It was still warm in the house and he hadn’t even turned the heat on,” Nemecek says.
Dubbed “Unity House,” the home has impressed students and green building aficionados alike since its fall 2008 opening. Created by the Massachusetts Institute of Technology “House_n” Research Consortium and New Hampshire-based Bensonwood Builders, Unity House combines new technology with commonsense building techniques to create a beautiful and energy-efficient space.
How It Works
During the day sunlight shines through 24 feet of triple-glazed windows on the south side of Unity House and soaks into the brown concrete flooring, where its warmth will slowly radiate come nightfall.
Solar panels on the roof provide more electricity than needed on most days, with the extra electricity sent back into the local power grid. When extra heat is needed, a super-efficient Hallowell cold-climate heat pump kicks in. In summer, vines will grow on the south side to shade the house, while well-placed windows will provide a strong cross-breeze to keep things cool. The building is expected to be granted platinum LEED certification, the highest rating available, by the U.S. Green Building Council.
With Unity House, Bensonwood Builders and MIT did much more than design a green home; they designed a green way of building homes.
Randall Walter, a Bensonwood Builders architect and one of the house’s three designers, says Unity House presented a unique challenge since it was to be a home, a classroom, and a forum for events. The solution, he says, was to create flexible multipurpose rooms.
Like multiuse rooms in commercial buildings, Unity House has several walls that can easily be dismantled within 15 minutes. The floor plan provides one large combination living room/dining room/kitchen and smaller rooms with removable walls that can be peeled back as needed for additional floor space.
The home’s plumbing and wiring systems are centralized in one area on the north side of the house to ensure easy accessibility in case of repair or upgrade. Using 3-D computer design technology, designers created logical layers of plumbing and wiring, a process Walter calls disentanglement, to make everything easy to reach.
“You don’t bury something that has a five-year lifespan into things that have a 200-year lifespan,” Walter says.
Bensonwood Builders also concentrated on erecting the home in an energy-efficient manner with green prefab construction at their factory for easy on-site assembly. Walter says the goal was to cut down on the 8,000 pounds of waste the average new-home construction project produces. The waste from Unity House amounted to three barrels.
“When people think about building on an island, everyone suddenly gets very efficient,” Walter says. “My argument is that every job site’s an island.”
Watching the Meter
But Unity House is not just a highly efficient machine that can run itself; it requires attention by its occupants to run at peak efficiency. This suits Thomashow and his wife, Cindy, who is the director of the college’s Center for Environmental Education, just fine. He says Unity House keeps him in touch with the natural rhythms of the day.
“You need to be very aware of closing the shades at night,” he says. “You really tend to live much more by the sun.”
Thomashow keeps tabs on the home’s electricity usage through the outdoor and indoor electric meters. In the fall, Unity House had stockpiled some 400 kilowatt hours of generated electricity, but the home has been running a deficit of a couple hundred kilowatt hours so far this winter. While that total should be easy to make up in the warmer months, the temporary deficit doesn’t sit well with Thomashow.
“The gamester and warrior in me wants to win this,” he says.
The home is just the latest move for a learning institution that has focused on environmental sustainability since its inception. Founded in 1965, Unity College’s classrooms were built partly from recycled chicken coops. In the ’70s, the college was working toward energy efficiency before most people knew of the term “energy audit.” In 1992, the college rescued the famous Jimmy Carter solar panels that once sat atop the White House from storage. The panels helped power the school’s cafeteria before ceasing to function; one panel was put on display by Google at the Obama inauguration.
More recently, the college has joined a growing number of higher learning institutions dedicated to curbing their carbon emissions. Unity College buys power from renewable energy sources, retrofits existing buildings to be more efficient, and builds more efficient buildings to replace inefficient ones.
Unity House has become the symbolic culmination of that energy-conserving process, a home that produces electricity for other homes. Thomashow understands that his home is being watched by the world.
“We’ve become a living laboratory on sustainability initiatives,” he says.
Coming Soon
Homes with a similar design to Unity House may be appearing in a neighborhood near you. Unity House’s design and prefab construction process were created to be replicable, and the home’s features are modular, so future clients can mix and match them.
The overall price tag for Unity House is hard to gauge. The college paid roughly $200 per square foot for the house, which is comparable to traditional home-building costs, but that price doesn’t factor in research time. If Bensonwood has quantified its costs, Walter remains mum on the subject.
“A car manufacturer never has to tell how much the first car costs,” he says.
But since the process of making Unity House is repeatable, Walter says the price for similar homes should fall below $200 per square foot. The house hasn’t even been through all four seasons, but people are calling Bensonwood hoping to buy similarly designed homes.
That doesn’t surprise Thomashow after living in Unity House.
“Over time, we’ll see more and more of these kinds of dwellings,” he says.
