The paper is part of a larger study, in which the author investigates the effects of radiant heat transfer from exterior shading devices on the surface temperatures of glass using an experimental setup at the Solar Laboratory at Arizona State University, Arizona, USA. Shading devices play an important role in controlling the amount of direct solar radiation entering the interior of a building. Designers provide various material alternatives while designing these exterior-shading devices. The main idea is to improve the aesthetic appearance of the building facade while at the same time providing an efficient shading system to the fenestration. One important effect that is overlooked by most of the currently available whole building simulation tools is the long-wave radiant (re-radiation) effect these shading devices have on the glass temperatures. The paper investigates the radiant effect using sunshades made of three different materials and compares the effectiveness of RADTHERM (a simulation tool used to simulate the experiment). (C) 2003 Elsevier Ltd. All rights reserved.