Situated on the grounds of the former military barracks of Luttow-Vorbeck in the district of Hamburg-Jenfeld, the Jenfelder Au project plans to build 835 households incorporating the Hamburg Water cycle ©: A closed-loop waste-water management system including rainwater infiltration basins, a setup for testing two methods of grey water collection and treatment; and separate vacuum system for black water collection with nutrient and biogas recovery. This project is part of the IBA (Internationale Bauausstellung) Hamburg.