Buildings made from wood are good for the climate and protect the Earth's resources. Nevertheless, even wood is not infinitely available, and forests are valuable ecosystems for animals and plants. So how can the utilization of wood resources from the forest be optimized in such a way that the smallest-possible amount of forest area is used in order to build a house? What building materials are needed for this purpose and what can be saved through recycling? What ecological and economic advantages does this bring for urban and rural areas? These are the central questions in this international project. The aim is to build two demonstration houses. At the Fraunhofer WKI, we are developing flame-retardant bio-materials for this purpose.