The thermal end energy consumption will become less important in the coming years when compared to the total primary energy consumption of a building. Fig. 2 shows the heating consumption, including the domestic hot water supply, of 68 objects with reference to the heated gross area. The different colors rep- resent the various energy sources used to heat the building. The mean value is 93 kWh/(m2a) and therefore significantly lower than the energy consumption of single family houses (131 kWh/(m2a)) [6]. Some of the buildings analyzed use district heat as an energy source. Thus, the generation and storage losses are not included in the measured energy consumption of these school buildings.