Toward low energy cities : A case study of the urban area of Liège

Within the framework of sustainable development, it is important to take into account environmental aspects of urban areas related to their energy use. In this article, a methodology is proposed for assessing residential energy uses for buildings and transport at the city scale. This method is based on the use of GIS tools combined with a statistical treatment of urban and transport criteria. The methodology allows to model buildings and transport energy use at the city scale, as well as to consider the possible evolution of the city energy consumption and to simulate the effects of some strategies of urban renewal. An application is given to study different energy management strategies for the urban area of Liège. Buildings and transport energy consumption are compared at the city scale and their possible evolution in the future is highlighted. Forecast scenarios on future energy policies for Liège’s building stock show that the European Directive on the Energy Performance of Buildings and even more selective energy policies applied only on new buildings are not sufficient to widely decrease buildings energy consumptions at the city scale. The renovation of the existing building stock has a much larger positive impact on city energy consumption reductions. The methodology developed in this article can be adapted and/or reproduced on many other urban regions in Belgium but also in Europe or even further.