To tour Stuttgart's Weissenhof Estate, the site of the 1927 Deutscher Werkbund exhibition of prefab homes designed by modernist icons, is to walk through architecture's future past. But within the housing estate, at Bruckmannweg 10, an ongoing research experiment will potentially shape architecture's green future. The Active House B10, a prefab, glass-fronted box of a home built in a single day, features an energy management and production system that works on many more dimensions than its simple rectangular frame suggests. The super light, fully recyclable 970-square-foot building with a self-learning, self-regulating energy system generates 200% of its energy needs with a grid of photovoltaics on the roof. It's literally a "power plant," according to architect Werner Sobek, which will power a pair of electric cars and as well as a museum housed inside a Le Corbusier-designed building nearby. Sobek explained how the massive advances of B10 may shape the built environment for years to come.