Paper presentation at the Splitech conference. The vast amount of data from multiple domains and sources available today is a valuable resource for improving energy use in buildings. We have created ENERSI, a platform which enables the development of services to integrate and analyse data from multiple sources, including: Energy Performance Certificates (EPCs), cadastre, geographical data, census sections, technical building inspections, catalogues of refurbishment measures, and building renovation assessment tools. In this paper, we present two platform services based on the integration of these data which are addressed to two specific end-users: one that enables building owners to know the performance of their dwelling, and suggests recommendations to improve it; and a second one, for city planners to assess the performance of a district, municipality or region, in order to identify urban areas and groups of buildings to be improved, and the corresponding investment costs. The purpose of these services is to provide each type of user with a comprehensive and synthetic view of the energy performance, at the building and urban levels, which enables them to assess their current status in terms of energy efficiency and take decisions to improve it. This paper introduces the two services that will be publicly available in the ENERSI web portal and in the websites of the public administrations which have provided support to the project. The experience of developing these services has shown that the exploitation of integrated data is only possible if the needs of specific end-users have been properly identified, so that the information is presented to them in ways that they can easily understand in order to take decisions to improve building energy efficiency in their particular decision-making realm.