When Keith Collins called on Kaplan Thompson Architects to design an outbuilding for his wife, Mary, it seemed like a straightforward commission. But almost immediately Collins, a repeat client, revealed a loftier goal: to create a beautiful, high-performance demonstration project that could help teach the industry about “net-zero” houses. “We did research and decided that we wanted a flexible building that was livable, affordable, sustainable, and replicable,” explains Phil Kaplan, AIA, LEED AP, principal of the Portland, Maine-based firm.

Collaborating with the client, Walpole, N.H.-based prefab manufacturer Bensonwood, and a variety of green engineers, Kaplan Thompson came up with the BrightBuilt Barn, a 756-square-foot, single-level outbuilding on the clients' property in Rockport, Maine. The structure is designed as a working studio, but Kaplan says it can easily be configured into a one- or two-bedroom house.

The 90 percent prefabricated barn measures 18 feet wide by 42 feet long and has a continuous, superinsulated R-40 shell. Its 2x6 exterior walls comprise blown-in cellulose insulation, timber-frame structural insulated panels, and triple-glazed windows. Built without a furnace, the barn has an air-to-air heat pump (which operates at temperatures as low as 0 degrees Fahrenheit), a 5-kilowatt photovoltaic system, solar hot water, and a heat recovery ventilator. “When you have a house this tight, you need [the ventilator] to bring fresh air into the building,” Kaplan says.

One of the project's most exciting features is its real-time energy feedback system. A series of LED lights installed around the base and inside the structure are programmed to glow in three colors that signify current energy usage levels. Bulbs turn green when the building is using less energy than it's producing, yellow when it's borderline, and red when it exceeds net-zero goals. Live feedback encourages human modulation of energy use, Kaplan Thompson argues, and has been shown to reduce electricity costs by up to 12 percent. In addition to the lights, a large meter on the structure's front façade monitors energy use and consumption and displays the information on the BrightBuilt Barn blog (www.brightbuiltbarn.blogspot.com).

Since completing the original BrightBuilt Barn, Kaplan Thompson and Bensonwood have transformed the concept into a product line that can be purchased at a base price of less than $200,000 (not including site and foundation work and other essentials). Several upgrade options also are available.

Kaplan says the project team hopes to be able to offer the plans and specs online by summer “so people can build their own” BrightBuilt Barns. But there will be a caveat: “They must agree to log their [homes' performance] data on the website,” he says, adding that such information-sharing is what the barn is all about.

As his firm sees it, performance data from other BrightBuilt Barns will “stop our guessing at the combinations of systems and assemblies that will eventually bring us to attainable, carbon-free homes” and at long last make them a reality.