A novel concept based on the dynamic use of phase change materials (PCM) in building envelopes is presented in this paper. The concept aims at breaking the main technical barriers that PCM have been dealing with in its application as passive cooling system: (i) solidification process of PCM is limited and (ii) peak cooling load is delayed but mainly discharged indoors. The concept relies on the ability of the system to modify the position of the PCM layer inside the building envelope with respect to the insulation layer. A proof of concept evaluation based on a numerical tool demonstrates the cooling load reduction potential of this technology when implemented in different construction systems. PCM peak melting temperature as well as the daily activations of the system were optimized using a Particle Swarm Optimization (PSO) algorithm. The numerical results indicate that the dynamic system facilitates dramatically the solidification process of PCM, allowing the system to be designed with lower PCM peak melting temperatures. The potential of the system to charge PCM which solidifies at temperatures lower than indoor set point, allows the technology to be used not only as a thermal barrier but as a cooling supplier system.