In this paper, a finite element numerical algorithm for the simulation of two-dimensional problems of heat transfer with phase change is validated, comparing the numerical results with the experimental ones deriving from tests carried out on two different kinds of PCM containing sandwich panels. The very good approximation affecting the numerical results, as compared with the experimental ones, suggests that it can be a powerful design tool for every kind of PCM containing building elements. Moreover, four prototypes of PCM containing sandwich panels for prefabricated walls were tested (two of them used to validate the numerical finite element method for design purposes) in a test-room capable of simulating several kinds of outdoor and indoor environmental conditions, aimed at evaluating the energetic performances of such panels, which make them suitable for use in different climatic contexts or in different elements of buildings. The possibility to adapt such basic technology to manufacture panels with several stratifications allows their installation both on ceilings and walls and in several climatic and design contexts. (c) 2005 Elsevier B.V. All rights reserved.