One way to reduce CO2 emissions is to decrease energy consumption in buildings. A promising approach to achieve this goal is the use of phase change materials (PCMs) as thermal energy storage systems for thermoregulation applications. However, the integration of PCMs into building components is a challenge. Microencapsulation of PCMs has shown promising results as a passive form to improve the thermal performance of building materials, reducing the wasted energy with thermal comfort. In this context, this work focuses on two different aspects of microencapsulated phase change materials. The first is a numerical investigation of the internal temperature behavior of building walls with a thin layer of concrete with capsules. A one-dimensional transient method is proposed, in which the presence of the microcapsules is modeled through a concentration function and the phase change process is modeled by the effective heat capacity method. The effects of the position of the PCM layer, concentration, PCM melting temperature, and phase change enthalpy on the internal temperature profile of the wall were evaluated. In addition, we fabricated microencapsulated PCMs using poly(dimethylsiloxane) (PDMS) as the shell material and calcium chloride hexahydrate (CaCl2 . 6H2O) as the PCM core. The preparation was carried out using glass capillary microfluidic devices to ensure the production of monodisperse microcapsules with adjustable geometrical properties such as size and shell thickness. The study shows a direct relationship between the position and concentration on the internal temperature as well as the reduction of the internal temperature of the walls. We were able to fabricate and store PDMS/CaCl2 . 6H2O microcapsules with tunable properties. Finally, preliminary thermal efficiency tests were conducted which showed that this shell/core combination was not ideal for these applications. However, based on the promising results of the numerical model, new combinations will be developed and tested in future work.