External shading affects the solar energy incident on a window and the transferred energy within the room through the window. In present study, the effect of advanced glazing and overhangs on the solar energy transmitted into or lost from the room through the fenestration areas have been evaluated for typical residential buildings in Tehran, using EnergyPlus (TM) software. It was found that appropriate overhangs or side fins in the south, west and east windows would lead to the optimal reduction of the annual energy transferred into the buildings and can have an energetic behaviour equivalent to high performance glazing. The results have been summarized in a table to simple selecting the best window with different glazings, overhangs and side fins based on energy rating. (C) 2010 Elsevier Ltd. All rights reserved.