As one of the effective measures to cope with the continually increasing energy consumption in the building sector, BCHP (building combined heat and power) systems have been paid great attention in both developed and developing countries. To understand the overall benefits of a BCHP system, comprehensive assessment of system performances is necessary. In this study, a multi-criteria assessment model has been developed by combining the improved GRA (gray relation analysis) approach and the AHP (analytic hierarchy process) method. As an illustrative example, two building categories located in different climate zones in both Japan and China have been selected for analysis. In this way, the influences of climate condition, building type as well as market data on the introduction of BCHP systems have been examined. According to the simulation results, the BCHP systems in Japan achieve more benefits than that in China; and the rank of regions for the same building type may vary in different cases for both countries. In addition, the coldest region always enjoys the best overall performance, followed by the hottest zone and mild climate zones in Japan; on the other hand, the influence of climate condition on the performance of BCHP systems in China is inexplicit. (C) 2016 Elsevier Ltd. All rights reserved.