Performs hourly simulations of buildings, in order to provide mechanical, energy and architectural engineers or architects with accurate estimates of a building’s energy needs and temperature profiles. The zone models of COMFIE are based upon a finite volume method on which a modal reduction technique is applied. The output comprises the yearly and hourly heating loads, hourly and mean temperatures in the thermal zones. COMFIE building model is also coupled to additional modules (PV generation, earth tube). Graphs and histograms may be obtained from PLEAIDES, the user-friendly interface of COMFIE.