Nowadays national and international directives have focused on improving energy efficiency in the building sector. According to them, energy consumption and emissions of buildings must be reduced. This can be achieved by balancing energy demand in buildings. In this context, this paper proposes a buildings' energy demand balancing method using the building energy consumption simulation program IDA ICE and real measurements. A 3D model of the building was developed, energy consumption and indoor climate of the building was monitored throughout the year, the behaviour of the occupants (a survey was conducted) was analysed, dynamic change of the weather was studied and all data were integrated into IDA ICE simulation. In order to increase the energy efficiency of buildings, the possibilities of optimization of heat production equipment and heating devices, as well as inspecting and optimization of ventilation and cooling equipment were considered. By adjusting the parameters of the heating system of the researched object, the energy consumption of the auto centre decreased to 39.3 kWh/m2 per year. One of the most popular methods of balancing energy demand in recent years-the creation of smart grids-is also considered.