Following the pioneering work "Tokyo Half Project" promoted by the Alliance for Global Sustainability (AGS), a geographical information system has been developed to model the energy requirements of urban areas. The purpose of this platform is to model with sufficient details the energy services requirements of a given geographical area in order to allow the evaluation of the integration of advanced integrated energy conversion systems. This tool is used to study the emergence of more sustainable cities that realize energy efficiency improvement measures, integrate energy efficient conversion technologies and promote the use of endogenous renewable energy. It is based on techniques at the crossroads of three domains : geographical information systems, urban energy modelling and process integration and process design techniques. The model is illustrated with case studies for the energetic planning of urban district in Switzerland.