A method based on dimensional analysis is proposed for a natural ventilated double facade energy performance study. The 14 non-dimensional numbers defined, with physical meaning, can be used to describe thermal and energy performance of different facade designs. A comparison between non-dimensional numbers solved by simulation, experimental data, and the obtained and validated correlation results is reported. A simple tool to evaluate thermal performance of a solar chimney is provided. Applying it, useful design indications can be derived also by varying simple parameters using thermal and physical data easy to get. (C) 2003 Elsevier B.V. All rights reserved.