Non-dimensional analysis is proposed as a method to analyse mechanically ventilated double glazed facade energy performance. The 12 non-dimensional numbers defined, can be used to describe thermal and energy performance of interactive facade designs. A comparison between Nusselt number solved by experimental data and Nusselt calculated by the validated multivariable correlation function is reported in the present paper. Due to its wide validity field the proposed method can be used to analyze thermodynamic performances of glass double-skin facades with mechanical ventilation. Applying it, useful design indications can be derived also by varying some parameters using thermo-physical and climatic data easy to get. (c) 2005 Elsevier B.V. All rights reserved.