A method to investigate the potential of south-oriented vertical surfaces for reflecting daylight onto oppositely facing vertical surfaces under sunny conditions

An average monthly variable, called the Obstruction Illuminance Multiplier (OIM), defined as the ratio of the illuminance received on a vertical surfa ce due to light received from the sky, ground and the obstruction to the il luminance on the same surface without the presence of the obstruction, is p roposed as a simple tool to investigate the potential of perfectly diffuse vertical south-oriented facades to reflect daylight onto the opposing facad es. (C) 1999 Elsevier Science Ltd. All rights reserved.