Energy policies at the urban level may result in long lasting effects and can successfully influence the energy performances of an urban system if we consider the whole built environment and focus on the energy renovation process in existing buildings. Undoubtedly, cities have a high level of complexity, especially considering problems related to obtaining suitable information about a building's energy performance and consumption. This study developed a methodology able to characterize the energy performance of the built environment in a city or neighbourhood and to evaluate the effects of different energy strategies. The methodology was designed to be as simple as possible, not time consuming and applicable to all Italian towns, as well as elsewhere, if basic building information are available; the main phases of the methodology were the collection and analysis of the available data about the built environment and the implementation of a Geographic Information Systems (GIS) city buildings database. To test the developed tool, the city of Milan was considered as a case study. The authors hope that this methodology will be able to support energy policies at the urban level, taking into account the approaches of different stakeholders to develop low carbon models of settlements. (C) 2012 Elsevier Ltd. All rights reserved.