Standing proudly on the outskirts of the Danish city of Aarhus is an experimental eco-home where one brave family is testing out life with the latest cutting-edge sustainable design. For the past year, Sverre and Sophie Simonsen, along with their three children, Axel, nine, Anna, seven, and baby Marie, have been living in the world’s first Active House—a building so technically advanced that in 40 years it will have created enough energy not only to support the family inside along the way but also to pay back the energy used for its materials and construction: a house, in short, with no carbon debt.
It’s one of eight prototype homes being constructed across Europe by the Danish window company Velfac. A test family will occupy each of the houses for a year while the building’s performance and the family’s experience is monitored. Having seen an advertisement on the Internet, the Simonsens jumped at the opportunity. "Like most Danes we were interested in the environment beforehand," says Sophie, a secretary, "but here was a chance to actually do something about it." Sverre, a chemical engineer, was also keen to road-test this slick bit of architecture. "Our old house is a typical 1970s suburban home with lots of small rooms, little windows, and dark corners," he says. "I’d always wondered what it would be like to live in a really modern open-plan building." Having seen off the competition from 40 other families, they made the move—less than a quarter of a mile up the road but a gargantuan leap in terms of their carbon footprint.
A different architect designed each Active House. The Simonsens’, an angular building perched on a sloping plot, is by Aart Architects, an up-and-coming local practice. "The starting point was the roof," says architect Anders Tyrrestrup. "We were restricted to one-and-a-half stories by local planning regulations and the south-facing side needed to be angled at 35 degrees to optimize solar gain." By creating a steep northern pitch and stretching the south-facing side, the firm cleverly maximized the roof area that gets the most sun.
The materials—a timber frame, and slate and Douglas fir cladding—were selected for their low embodied energy and easy maintenance. The monolithic slate skin merges brilliantly with the solar panels positioned on the roof. "We imagined it as a cross between a home and a stealth bomber," says Tyrrestrup.
Most impressive is the subtlety with which the building’s forward-looking environmental agenda has been woven into the thoroughly modern design. "Hopefully, the project demonstrates how by integrating new technologies at the design stage, rather than adding them as an afterthought," Tyrrestrup says, "we can produce a new architectural language with a deeper meaning."
Unsurprisingly, considering the sponsor, glass features heavily in the house with the equivalent of 40 percent of the 2,045-square-foot floor area (roughly twice as much light coverage as in the average home) bathed in light coming through the triple-glazed, argon-filled windows and their super-insulated frames. In most European eco-homes, large windows on all but the southern facades are frowned upon due to the material’s poor insulating performance, but here every room receives light from at least two different directions.