33649 Bielefeld-Quelle: 96 units, architect: Hans-Friedrich Bültmann, special features: all buildings are equipped with composting toilets and the highest composting toilet in Europe is located on the 5th floor. Further water measures: rainwater infiltration, own drinking water source; a reed sewage treatment plant was planned but could not be realised. Energy: BHKW, local heating network, internal cable TV, telephone distribution. Social: KiTa, craftsmen's yard, cooperative project. Economy: Development as a large plot, low-cost construction with partly much own work. Construction time: 1997