Although today's drinking water and sanitation system is an achievement from a hygiene perspective, it is not optimal from an ecological and resource-efficient perspective. The building owner Rüegg is planning to renovate a single-family home. In addition to the energy renovation, the water system should also be converted into a resource-saving and future-oriented concept. The aim of this pioneering project is to develop the basis for the integration of water and nutrient cycles into existing buildings, using the case study of the building owner Rüegg. In collaboration with the building owner, this project will examine the renovation of the single-family detached home with regard to the integration of water and nutrient cycles.