The article presents the results of experimental studies of partitions containing phase change materials. The main objective of the measurements was to determine the actual effectiveness of the used materials and their impact on energy storage capabilities through building partitions. The light partition component containing a finishing layer of organic material undergoing a phase change was the subject of research. The heat flux and temperature distribution on individual component layers were recorded while changing the temperature conditions of the surrounding air. The cycle of temperature changes has been chosen to model the probable conditions inside buildings located on Polish territory. The results made it possible to determine the actual effect of PCM applications in partitions on heat accumulation capacity increase and thermal conditions of the component. The article also addresses the issue of determining the parameters of material for which a very strong dependence of the specific heat and temperature exist. When used in construction materials, phase-variable thermal properties of the materials used must be accurately known, since the system efficiency depends on the thermal properties of materials. The article presents an attempt to determine the properties of the PCM as a function of temperature using the equipment consisting of heat meter, electronic sensors and thermocouples temperature.