At the present time in Hong Kong in its hot and humid climate, a single pane, clear glazing is most often used in windows of tall residential buildings. During this study, we employed HTB2, detailed building heat transfer simulation software, to evaluate a decrease in the yearly cooling load (Q) and in the peak cooling-load (D) in two residential flats due to different glazing single pane types and different flat orientations. The investigated glazing types were clear glazing, tinted glazing, reflective glazing, and tinted and reflective glazing.