The home’s 20-meter roof span was built using timbrel vault construction, a classical building technique that has been largely forgotten since the onset of modern high-strength materials. The roof features a layer of 26,000 locally handmade clay tiles mortared together to make a supporting web. A green roof was applied on top to help regulate the home’s interior temperature, and the home’s rounded shape reduces exterior surface area which in turn saves energy.
The house received an A-A rating on its Energy Performance Certificate (EPCs) and it is also on its way to becoming the first certified Passive House in England. New technologies compliment the old to provide the 3000 square-foot home with an extremely energy-efficient shell. Triple-pane windows to the south help heat the internal thermal mass and a first-of-its-kind vacuum exterior door offers the equivalent of 20 inches of foam insulation.
The tight building envelope requires a HRV to provide fresh air, and the home supplements passive heating strategies with a biomass boiler. A combination solar-electric and solar hot water array provides the home with ample supplies of renewable energy. The home even incorporates Phase Change Materials (PCM) to effectively store heat in the winter and regulate heat in the summer. The rest of the walls are insulated with cellulose, or shredded newspaper. The home harvests roof water for use indoors as well.
The interior finishes include a recycled glass bath floor and recycled tire matting on the main level as well as a tile ceiling that spans the internal boxes. Even the staircase gets into the act with bricks mounted on a parabola span.