Integration of building materials incorporating PCMs into the building envelope can result in Increased efficiency of the built environment A PCM-enhanced wall system is proposed in this paper and a simplified model for the heat exchange between the indoor environment and ambient was developed The objective of the study was to assess the effect of occupancy pattern and ventilation on the energy savings potential of the wall system It was found that (1) the occupancy pattern influences the value of the PCM melting point for which maximum energy savings value was reached and (2) the ventilation and its pattern reduces the relative value of the energy savings 2010 Elsevier B V All rights reserved