In view of the necessity to decrease the energy consumption world-wide - especially of the industrial nations - the energy supply enterprises, in particular, are requested to find new solution formulations to an environmentally acceptable energy supply. the municipal works in Hanover have developed a sequence of pilot projects and measures which serve this objective. Among these are energetic reorganization of existing buildings within the framework of the thermics programme of the EU, the proof that the energy demand of the new houses can be economically limited by a low energy house programme of about 50kWh/m(2), the suggestion to save LP up to 40 MW of the electricity demand, the erection of a housing estate for the EXPO 2000 producing only 40% of the at present usual CO2 emissions of modern residential areas.