Solar Energy, Vol.64, No.4, 179-188, 1998
The high-rise opposing facade in clear sky conditions - Not always an "obstruction" to daylight
The opposing building facade is an omnipresent feature for buildings in the urban commercial setting. In clear sky conditions, there are large surfaces of building facades that have the potential of reflecting sunlight incident on them. When the sun is behind a building (so that the solar facade azimuth is greater than 90 degrees), the building opposite potentially acts as a passive daylighting device to if. The work discussed in this paper shows that the performance of this device varies for each floor and for different building densities. Using the ADELINE simulation software, a street with high rise buildings opposite each other is modelled in clear skies, and daylighting is calculated in rooms at different door levels. Comparisons are made with daylighting of the same rooms without an obstructing building in order to observe the effect of the "obstructing building" to daylighting. Preliminary results indicate that the opposite facade of high rise buildings has the potential to be considered a passive daylighting device in particular contexts. As a passive device, the opposing facade could be given attention by urban designers and planners, as well as by those drawing up building legislation for the urban built environment. It would be desirable and important for users of the built environment, to determine future developments from the point of view of how opposing facades affect daylighting. This approach could have implications for energy efficiency and conservation and would utilise the free resource of solar radiation more effectively.