Light shelf was developed to create uniform indoor illuminance. However, in hot
climates the unshaded clerestory above the shelf transmits high solar heat gain. In dense
urban context, these advantages and disadvantages might vary regarding the context and
position of the fenestration. This study employed an integrated energy simulation software to
investigate the effectiveness of light shelf application in a tropical urban context in terms of
building energy consumption. Radiance and EnergyPlus based simulations performed the
effects of urban canyon aspect ratio and external surface albedo on the daylighting
performances, space cooling load, as well as the lighting energy consumption of the building
equipped with lightshelves in 2 humid tropical cities. Comparison of the energy performances
of 3 fenestration systems, i.e. fenestration without any shading device, with overhangs, and
with light shelves, yielded some recommendations concerning the best application of light
shelf on the certain floor levels and aspect ratio of the urban context.