Efficient integration of phase change materials (PCMs) into buildings’ envelopes requires the mathematical modeling of PCMs and whole building systems, which is essential for the optimal design and material selection. Therefore, building performance simulation (BPS) is a cost-effective and time-efficient solution. However, currently, only a few BPS tools embed comprehensively verified and validated PCM models. This study presents a procedure of verification and validation of PCM models for building’s envelopes developed in Modelica employing an approach similar to ASHRAE Standard 140, consisting of empirical validation, analytical verification, and comparative testing.In order to characterize specific enthalpy changes and specific heat capacities of PCMs, three temperature-dependent continuous functions were proposed and validated with experimental adiabatic scanning calorimetry (ASC) data for a paraffin based PCM - RT27. Among the models, the arctangent function model behaved accurately across empirical data. Based on the model, the PCM heat transfer model for a semi-infinite PCM slab was verified analytically using the one-phase Stefan problem, where temperature evolutions at various depths of the slab were compared. For a wall with more realistic geometries and boundary conditions, a dynamic wall simulator for a multi-component wall integrating a microencapsulated PCM layer was selected, where simulated heat fluxes on inner surfaces of the wall were compared to the results of a validated numerical model. Lastly, the accuracy of the PCM model was tested on the whole-building level, thereby the variation of the average inner surface temperature of a building’s wall was compared to measured data.