The current climate and energy context is triggering the massive deployment of solar energy technologies in the short term. As a consequence, the number of Photovoltaic (PV) systems that will be set up in urban areas will drastically increase. Such large-scale integration must be guided by careful consideration of a diverse set of criteria, including energy resources and demand, as well as socioeconomic and environmental factors. In this paper, a decision aiding approach is introduced to rank a set of buildings based on their suitability to host photovoltaic systems in the particular case of urban environments. The study takes place in the context of a Franco-Swiss project covering the Grand Genève (Greater Geneva) agglomeration. A list of decision criteria is defined and the ELECTRE III outranking method is used to solve the problem and provide efficient ranking of the different solutions.