Similarities of a reduced-scale building model using air as the working fluid for buoyancy-driven natural ventilation have been analyzed and experiments were carried out using the scaled model for a common natural ventilation building, which has open office floor plans connected to a central atrium. Both open and closed cases have been investigated for the stack vents, located at the top of the atrium. Inputs for the scaled building model were taken from results measured in the prototype building by the authors. The parameters of the scaled building model's experiments thus were used as inputs into a computational fluid dynamics (CFD) simulation model to compare predicted and measured airflow patterns, temperatures and velocity distributions in the scaled building model. (C) 2011 Elsevier B.V. All rights reserved.