The development and industrialization of latent heat thermal energy storage technologies require a thorough mastery of the thermophysical properties of phase change materials (PCMs) used for the storage. These properties are often dependent on the material's temperature, and the literature highlights the influence of their variation on the performance of latent storage systems. In this study, the influence of the variation of the thermal expansion coefficient on the performance of a latent storage unit was analyzed. Following this numerical analysis, an experimental setup was proposed to accurately measure the temperature dependence of the liquid phase density and the thermal expansion coefficient of PCMs. A precision of more than 99 % was reached for the liquid phase density when compared to data obtained using the D5-METTLER TOLEDO densimeter and to water data from the literature. The experimental procedure was then applied to the characterization of six PCMs for building applications.