The modern energy-saving house combines maisonette and regular apartments as well as a commercial unit on the ground floor for art and culture professionals. The monovalent energy system heats through a heat pump which supplies geothermal heat through two Geo-Engroundwater circulation wells. The location in Berlin-Mittehas a powerful aquifer and thus, is well-suited for groundwater geothermal energy. The groundwater circulation wellextracts groundwater, feeds it into the heat pump and back into the aquifer. The suction and injections wells are placed approximately twenty meters apart from one another in the groundwater circulation well and are only located in a single borehole. In summer the groundwater is directly used for cooling the building. This so-called passive cooling manages without operating a cooling machine and delivers the comfort of air-conditioning almost free of cost.Thehigh performance of the groundwater circulation wells and of coaxial structure of both well systems enables the construction of this large geothermal system on such a limited available space.