Panel elementary schools built in the era of massive prefabrication during 1970´s and 1980´ still dominate among the elementary schools in Bratislava, the capital of Slovakia. Although many of them has already undergone a major renovation, a number of these schools still remains more or less in original condition. The paper presents an energy audit of such a school built in 1983, made of prefabricated concrete panels - a building technology typical in that period for countries located in Central Europe. During the present study the school was still mostly in its original state, with only minor energy efficiency measures implemented in building constructions and technical systems. The school consists of seven pavilions, and besides of educational premises it also contains a kitchen with canteen, a gym and a swimming pool. A complex energy audit has been performed with the aim to suggest the most profitable energy saving measures. The calculated energy demand was estimated to 116 kWh/(m2.year) for heating and 24 kWh/(m2.year) for domestic hot water in the original condition. The energy audit has shown that after implementation of realistic energy saving measures the energy demand could be reduced down to 80 kWh/(m2.year) for heating and to 22 kWh/(m2.year) for domestic hot water, and that implementation of the saving measures is expected to become profitable after about 8 years. Simultaneously with energy audit, a pilot project of energy monitoring using the ET (Energy-Temperature) curve method was launched. The results of energy monitoring over the first heating season indicated poor manual control of the heating system resulting in lower room air temperature, which was reflected in lower satisfaction of the occupants with their thermal environment.