Nowadays, micro-generation technologies are well developed and these make local energy production more possible. In terms of building scale, in April 2009 the Japanese government decided to accelerate its efforts towards zero energy building (ZEB). However, it is said that achieving a ZEB status without a grid connection would be quite difficult. In this study, thus, the definition of zero energy building (ZEB) is extended to the community level, 'energy community', which is defined here as a cluster of buildings in which every building generates both heat and electricity using micro-generation technologies and shares both types of energy with the other buildings. This article describes energy-sharing possibilities among four buildings in Japan: an office building, a hotel, a hospital and a shopping centre. The comparisons of primary energy consumption of the separate and shared cases of buildings show that the energy-sharing cases have the advantage of energy management within the boundary compared with the buildings studied as separated cases. The combination of hotel and hospital has the higher potential for achieving ZEB status. The results of this study show that the advantages of energy sharing are dependent on the type of buildings in the combination and CHP operation strategy. (C) 2014 Elsevier B.V. All rights reserved.