Toward the realization of sustainable building "the egg of the earth"

The solar office building, named "the egg of the earth" was built in Hamamatsu city where climate is relatively warm and sunny, famous for eel dish. The building was composed by 6 solar offices and glass roof corridor, which tied offices. At designing this sustainable building, we had 3 targets, 1(st) target is the restoration of natural environment. The site was originally a part of eel pond near the shore of Lake Hamanako. We planed to remake the lakefront as original scenery before eel pond by using the original soil, plants and water plants. This attempt includes water purification of the lake by circulating water of the new pond and lake. The 2(nd) target is applying the zero emission system. The building was made of the lumbers from Local Mountain near by to reduce the carbon dioxide emission of transportation. Concerning about sewage system, wastewater is completely re-circulated. Wastewater drained from sanitary fixtures is treated by bacteria-based treatment system and reused for flush water of fixtures. 3(rd) target is the self-sufficient energy use, to raise energy self-sufficient rate, we applied the photo catalytic coated glass and screen for cooling. The process of verification and improvement is due to be introducing to society. A building outline and some measured data are reported in this paper.