A simplified dynamic building model was proposed and validated in this study. The structure of the new wall system is that of a three-layer sandwich-type panel with outer layers consisting of SSPCM wallboards and middle layer consisting of conventional brick. Each layers of the composite wall have different functions: the external layer connected to outside has a higher PCM melting temperature used in summer and the internal layer connected to indoor with a PCM melting temperature near indoor set point used in winter. The middle layer is brick for insulation. Few studies have involved simplified dynamic models of building structures integrated with double layers SSPCMs. The simplified dynamic model represents the brick layer by three resistances and two capacitances (3R2C) and the SSPCM layer by four resistances and two capacitances (4R2C) while the key issue is the parameters identification of the model. The parameters of the simplified model are identified using genetic algorithm (GA) on the basis of the basic physical properties of the brick and SSPCM layer. Validation results show that the simplified dynamic model can represent light weight walls and median weight walls integrated with double layers SSPCMs with good accuracy. (C) 2013 Elsevier B.V. All rights reserved.