The base load is taken over by a WP-Max hybrid heat pump. This type of heat pump is capable of transferring low-temperature heat (day edge position or bad weather) from solar thermal generation into the heat pump and increasing the coefficient of performance and thus the efficiency of this. For this purpose, solar thermal collectors were integrated into the façade of the building as part of the refurbishment measures. In the summer months, drinking water heating is largely provided by solar energy and is supported by the heat pump. In the winter months, the collectors and the hybrid effect of the heat pump will support the heating system. The entire production is controlled and regulated by the ratiotherm central controller.