In recent years advanced insulating materials presenting very low thermal conductivity or dynamic properties have been developed. To penetrate the market and to be widely adopted by designers some barriers have to be overcome. One of the main issue is to provide testing procedures and certified data able to give a reliable picture of their performance when applied to real buildings. Among the advanced insulation systems, VIPs (Vacuum Insulated Panels) seems to be particularly promising. VIP panels show a very low thermal conductivity, thus implying two sets of problems when evaluating their performance. On the one hand the laboratory analysis of their performance can be tricky and difficult to perform. On the other the overall performance of the panel under actual working conditions is not the one measured at the center of the panel, because of thermal bridging occurring at the edges of the panel, due to the panel envelope, edge and type of joint. Therefore firstly an extensive experimental campaign aimed at measuring the thermal conductivity of VIP panels, and of the performance drop off due to perforation of the panels, has been carried out through the Guarded-Hot-Plate. In second instance the evaluation of the overall performance of VIP panel, under conditions representative of actual configurations, has been carried out by means of numerical analysis, in order to take into account for thermal bridging effect in VIP panels, in real building applications.