This paper presents the energy modeling and simulation of a railway station building through thermal and electrical loads calculations. To address this problem, we have developed architectures of thermal and electrical models using Dymola/Modelica environment. Thermal model is based on the elementary components of Modelica Buildings Library associated with other internal (GDF SUEZ) and external libraries. As for the electrical model, we implemented a new library to predict and calibrate on real data provided by measurements the power consumption of several equipment into a railway station. In order to test the capabilities of the model, a reference railway station is selected to assess the thermal and electrical consumption of the building. Finally, we identify the electrical services with interesting potential for energy savings and load flexibility, and some suggestions for improving the consumption are pointed out as well.