Phase change materials (PCMs) have a high capacity to store latent heat, which makes them useful as thermal stabilizers or insulating barriers in various applications. The facade of a building is particularly important for maintaining temperature stability and minimizing energy consumption, as it acts as an envelope that protects the building from harsh weather conditions. To ensure thermal comfort inside the building, it is crucial to minimize heat loss due to differences between indoor and outdoor temperatures. The aim of this study is to reduce heat transfer between indoor and outdoor spaces. To achieve this goal, the study incorporates phase change materials (PCM) into the mortar of facade panels based on PCM's ability on retarding heat transfer and its ability to store heat. A novel experimental system was used for the study, which was created using a comparative method. It's expected that the addition of PCM will reduce the thermal conductivity coefficient of the composite material, resulting in lower energy consumption. The reference mortar used in the study was a prefabricated mixture of polypropylene fiber-reinforced concrete (PPFRC) with a constant water/cement ratio of 0.40. Samples were prepared by adding an organic microcapsule PCM with a melting temperature of 18 degrees Celsius and a diameter of 15 to 30 microns, to the reference mortar at varying rates. The experiments conducted showed that the expected efficiency in reducing the thermal conductivity coefficient of the PPFRC mortar due to the incorporation of PCM was directly proportional to the amount of PCM used in the reference mortar. As the proportion of PCM used increased, the value of the thermal conductivity coefficient value decreased. However, increasing the ratio of PCM used resulted in a decrease in the density and compressive strength of the composite. Therefore, in this study, the proportion of PCM was determined considering the physical properties and the expected thermal conductivity value of the composite material.