Town Administrations are increasingly facing the challenge to identify smart planning actions to reduce the cities' energy demand by improving the efficiency of the urban energy systems. Buildings play an important role in this regarding both the demand and supply energy. In this scenario, the neighborhood or district scale seems to be the most appropriate to implement a multi-disciplinary approach on which smart planning relies. This paper shows the application, to a district of the city of Palermo (Sicily, Italy), of a methodology for architectural-energy classification of existing buildings. Such methodology provides, regarding the building sector, an easy tool that can support smart planning at district scale using data available to the municipalities. The work also shows a first experimental approach for the neighborhoods' characterization. The basic idea guiding this work is to identify possible features and subsequent intervention actions for energy refurbishment in neighborhoods clusters. © 2016 IEEE.