Building envelopes are the interface between indoor and outdoor environment which affect the indoor heat gain and heat loss in the design of sustainable buildings. It is beneficial to identify the most important design parameters in order to develop more efficiently alternative design solutions. This study performs a sensitivity analysis of energy performance to assess the impacts of envelope design parameters and identify the important characteristics. Index of evaluation on energy and thermal performance (EETP) for residential envelops is introduced for the calculation of energy use. High-rise residential buildings with small and large window-to-wall ratio (WWR) are selected in four cities of hot summer and cold winter zone of China. Eight design parameters of envelope are analyzed and compared. Results show that: in cooling season, shading coefficient and WWR are the most vital factors; in heating season, wall heat-transfer coefficient and shape coefficient have crucial effects when WWRs are 25% and 50%, respectively; for annual energy use, wall heat-transfer coefficient and WWR are the most sensitive when WWRs are 25% and 50%, respectively; whether the WWR is small or large, solar absorptances of wall and roof and heat-transfer coefficient of roof have very slight effects. (C) 2013 Elsevier B.V. All rights reserved.