A villa built on a steep slope which overlooks Lake Yamanaka. Structural computation revealed that any buildings on this slope would be subject to a load of 1 meter of snow (200 kg per square meter). If the entire structure was to carry this load, however, each part would have to be quite big in order to avoid any deflection. Then the architect decided to provide a large folded-plate roof above the roof over the dwelling space so that the fallen snow would not affect the parts of the main structure. As a result, this villa turned out to be an extremely light-looking structure. The folded-plate roof also enhances the habitability of the villa by blocking out sunlight.