Farmhouse

"It only cost about $48,000 to build, which was incredibly cheap," says Turner of the Stealth Barn. "We got the Timber Frame Company to supply the shell, then we clad it and fitted out the interior and windows ourselves. The idea was to take the archetypal black tar-painted agricultural building and make an almost childlike icon of that."

The north wall of the IST home functions as a cut-away, offering a peek inside an efficient yet cozy dwelling. Architect Peter Jurkovič built the home for a woman who had sold her flat in the big city of Bratislava and wanted something that reminded her of the village life of her childhood.

With a few small changes and regular maintenance, existing buildings are some of the most sustainable around.

Built by a crew of three, the home makes a virtue out of being unfussy and straightforward. The north-facing glass wall under the gable, with a triple-glazed facade, doesn't require shading or insulation. The quick-to-build structure—which consists of just structural insulated panels (SIB) made from OSB panels with a foam core, and a concrete floor that retains heat—doesn't include any complicated systems or require much maintenance.