Energy certification of buildings, mandatory under the European Directive EPBD provides interesting data on the thermo-physical properties and geometry of existing buildings. Although the energy certificate is intended to provide the characteristics of individual buildings, so stimulating the real estate market toward ever better energy performance, data management of the certificates issued over time, using a national or regional energy cadastre, makes available a data base which is useful for energy planning in the building sector. This paper provides the needed results of a benchmarking study on data from the energy cadastre of the Lombardy Region, northern Italy. By integrating data from the energy cadastre (175.778 energy certificates) with the statistical data obtained from the national census, indicators were obtained on the energy performance of existing buildings. The energy indicators obtained, characterised by building type and construction period, normalised as a function of Degree-Days, become an effective tool for energy planning at local and regional scales. In the specific case, the energy indicators have been used to estimate the potential for energy retrofit of existing buildings in the Lombardy Region. The same indicators can also be used by municipalities for energy planning at the municipal or district level. (C) 2015 Elsevier Ltd. All rights reserved.