The rapid economic expansion of China has been accompanied by environmental issues that have necessitated a national energy conservation strategy. It has become apparent that more resources must be made available for a national programme of developing sustainable buildings with an energy-saving capability. This paper discusses how to achieve space heating and cooling as low as possible in the Chinese residual context, where three main issues need to be addressed: (I) climate variations - there are five different climatic regions partitioned by the Chinese authorities as severe cold region, cold region, moderate region, hot summer and cold winter region, and hot summer and mild winter region; (2) rigid building form multi-storey building block is the most constructed during the construction boom last decade resulting from the application of the national building regulations; (3) favoured fenestration design due to viewing purpose. This paper investigates the window size in relation to its corresponding annual space heating and cooling demand within the five different climatic regions. It quantifies the energy savings by energy-efficient measures in a step-by-step approach from the current representative scenario to the building regulative scenario and finally reaches the optimized scenario and concludes guidance for future energy-efficient residential building designs. (C) 2013 Elsevier B.V. All rights reserved.