The Digital Building Logbook as a gateway linked to existing national data sources: The cases of Spain and Italy

The Digital Building Logbook (DBL) was first introduced together with the Renovation Wave initiative, promoted by the European Commission and then defined in the proposal for a recast of the energy performance of buildings Directive, in December 2021, as a repository of relevant data on a building that aims to alleviate the current lack of information of the European building stock. Several data sources on buildings already exist at different levels in Europe, and their interlinkage is crucial for a proper data population of the future Building Logbook. However, these data sources are scattered and heterogeneous, thus, they need to be evaluated to determine their suitability for the DBL. This paper analyses the sources that currently exist in Spain and Italy, focusing respectively on Aragon and Lombardy region, and addressing their interoperability possibilities and the indicators collected. The results show that the available data are not fully aligned with the relevant indicators from the existing proposals for a European DBL, and that few data sources are currently suitable for the DBL, since most of them are not interoperable. Considering the features and limitations of the data sources, a dataflow general scheme based on the definition of the DBL is defined for each case study, and guidelines are presented on data collection and interoperability in order to make its implementation feasible at the European scale.