The design for the new speech therapy school in Griesheim near Darmstadt is inspired by the pine trees which are scattered across the site. The 890 m2 building consists of three polygonal, double-storey “tree-houses” and provides space for 110 students. The buildings were designed and placed on site to save as many of the existing trees as possible. They consist of a timber frame construction with round timber columns that support the cantilevered upper storeys. Covered bridges connect the three buildings and make them wheelchair accessible. With a heating requirement of 16.6 kWh/m2a the school almost meets the Passivhaus standard. Heat is supplied by the gas heating station of the neighbouring primary school; supply and exhaust ventilation is provided by 2-3 decentralised ventilation units for each treehouse.