Robust data on building energy performance are very important for assessing impacts of existing policy instruments and providing a quantitative basis for the effective design of future ones. GBPN is making substantial efforts in collecting, cross-checking and analyzing various data related to the building sector. However, serious data gaps exist in this field. A lot of data and numerical research results are so-called ‘black boxes’, which means that it is difficult or not possible to track the origin of the numbers and assess their quality. Therefore, one of the GBPN’s priorities is to share its expertise in data collection and analysis, by making the data publically available and involving other parties in an effective dialogue and exchange of data in order to improve its quality. With this purpose GBPN has developed several tools, that can be accessed on the official web-site. These tools provide data and results from GBPN’s research and can be used in an interactive manner to prepare visual outputs according to the user’s queries. A number of data in the tools are linked-open data, which increases its visibility and enhances the opportunities for data sharing, thus supporting the GBPNs mission.