This work focuses on examining the possible advantages for the urban sustainability, derived from the integration of transport, land use and energy systems. The main aim is to develop a GIS-based method that can help decision makers, either public or private, improving the economic, social and environmental sustainability of urban areas through an integrated transformation approach. As a result, it was possible to provide a spatial analysis technique based on seven synthetic variables and on the application of a cluster method able to identify the portions of urban areas where investments and urban integrated transformation processes can be more suitable, according to the dynamic relationships among transport, land use and energy systems. The methodology was applied to the Great London Area and lead to significant results: the cluster classes follow the transport railway network evolution within the study area boundary. The paper is organized as follow: in section 1 the integration of transport, land use and energy planning is investigated; following the introduction, in section 2, the GIS-based method is presented, followed by a description of the application to the Great London Area; in section 4, findings of the methodology are explained. In the last section, results and future developments are discussed.