Policy makers and administrative bodies are to prepare regional or local energy plans and an extensive employment of sun is important for their sustainability. Italy is a highly urbanized country with a high level of solar radiation, having an annual daily average of about 4-5 equivalent daylight hours and local governments should take advantage of the unexploited solar energy potential in their territories. The wide-scale application of PV in the built environment has been drawing interest in recent years and has become one of the major goals of the International Energy Agency’s Task 10 “BIPV on an urban scale”. Policy makers and administrative bodies need reliable tools that can facilitate plans for intervention in the built environment and the feasibility of a new preliminary rough estimation of the solar energy potential of buildings and infrastructures can be envisaged as a reasonable way to help local governments map the entire solar energy potential __ e.g. rooftops, facades, public squares, etc.__ and easily recognize places where shadows or current building requirements and restrictions do not permit PV installation. In addition to the aerial photos of the land Geographic Information Systems (at a local, regional, national and even international level) may constitute a useful multipurpose tool for performing accurate analyses. The intelligent use of this tool could bring basis for political and economical considerations and evaluations, so it could become a reliable practice in PV urban planning.