Due to their latent heat storage capacity, phase-change materials (PCM) incorporated in wallboards are an effective solution to reduce energy consumption inside buildings. This is achieved by incorporating PCM in construction elements made of cement-based materials. The purpose of this research is to evaluate both the thermal conductivity and the heat storage capacity of mortars and concretes with different amounts of PCM in order to evaluate their thermal performance. Therefore, a laboratory-developed transient plane source experimental setup was used to measure these properties. First, several mortar and concrete specimens including different amounts of PCM (0%, 4.5%, 9%, and 13% by total mass of cement) were manufactured. Then, the experimental setup was used to measure the temperature development on PCM-concretes and PCM-mortars for a period of 1,000 s. The collected data were analyzed to back-calculate the thermal characteristics using a numerical optimization procedure. Numerical findings using the finite-element method show that the testing procedure efficiently provides accurate estimations of the thermal properties of the tested specimens. It was found that cement-based materials incorporating PCM have lower thermal conductivity and higher heat storage capacity, which indicates the improvement of their thermal behavior.