The company that built this single-family home at the periphery of Cluj-Napoca exclusively plans and executes eco-passive houses that are certified by an international body. Since environmental consciousness and good thermal insulation properties were important material selection criteria, they chose the Energocell® foam glass granules for the thermal insulation of the foundation and the floor. The building's foundation was executed as a well foundation on which a reinforced concrete beam grid was placed. To provide a foundation insulation that is free of thermal bridging, the bottom and vertical sides of the beam grid were enclosed with foam glass granules. Under the reinforced concrete slab, a 50-cm thermal insulation layer of compacted foam glass granules was incorporated.