The aim of this article is to analyze the effects of energy conservation and emission reduction (ECER) on energy efficiency retrofit (EER) for existing residence in northern heating regions of China. Based on building energy consumption (BEC) testing data during heating period before and after the retrofit, combined with the theoretical calculation of BEC, the ECER effects are analyzed through an actual case of existing residential retrofit; meanwhile, residential electricity consumption between the retrofit building and non-retrofitted buildings is also compared. The case study results show that: (1) actual ECER effects of EER are obviously different from those analyzed by the theoretical calculation; (2) existing residential EER will have significant impacts on ECER; (3) building external wall retrofit always makes the largest contribution to ECER in high energy-consuming building, followed by external window retrofit; (4) the retrofit of building envelopes should be carried out with indoor heating system retrofit, heat metering and charging system together; otherwise, the phenomenon of "energy efficient buildings do not save energy" will appear; (5) the EER of existing building in northern heating regions will not only cause the obvious reduction of BEC in winter, but also lead to electricity consumption saved in summer. (c) 2013 Elsevier B.V. All rights reserved.