Abstract
In order to assess the coherence between the dynamic simulation and the EN ISO 13790:2008 quasi-steady state method, the authors, differently from previous works in literature, analysed the discrepancy sources directly for thermal losses and gains instead of considering only the final result in term of energy needs. In this first part, the deviations between the thermal losses are evaluated by means of an extensive use of simulation. More than 2000 configurations obtained by the factorial combination of different values for the building shape, envelope insulation and composition, window type and size, ventilation rate and climatic conditions, have been considered to identify the most important discrepancy sources and to improve the correspondence between simulation and quasi-steady state methods.