Three building case studies were chosen with the purpose of demonstrating the BIM4EEB BIM-based toolkit. The selected buildings are both social houses and residential apartments respecting the needs of vulnerable inhabitants. To increase the representativeness of the test case the buildings are located in three different locations with different climatic conditions, specifically Italy, Poland, Finland. For all the case studies analysed, BIM models were created with different levels of detail (LOD), which, thanks to the interaction with the BIMMS, make it possible to create a common environment for the representation and use of the data collected and subsequently shared between the different tools. Among the three demonstration sites, the Italian site is undergoing building envelope renovation interventions such as the realization of the thermal insulation with ETICS technologies and the replacement of external windows. In order to test the different tools, a demonstration procedure has been defined for them, constituted mainly by workshop activities and quantitative and qualitative evaluations. To assess the level of accomplishment with respect to stated objectives and project success a validation methodology based on Key Performance Indicators (KPIs) was delineated. Precisely, two categories of KPIs have been identified: “mandatory” and “secondary” addressing project objectives and in connection with the literature review and project use cases and tools. To calculate the KPIs standard baselines were estimated, such as are currently in an ongoing process to assess the traditional process that can be compared with the actual value associated with the BIM-based process. The chapter will present the methods and the first intermediate results of a demonstration process that is currently not yet completed and will later see a further application of the tools in dedicated demo sites. Environmental monitoring sensors were installed in selected apartments in Polish and Italian demo site, while were installed in common spaces for the Finnish building. Specific sensors set up have been analysed and chosen to fulfil the different needs related to the specific project outcomes. Inhabitants’ availability, technical condition and flat exposition were criteria followed for the choice of apartments. Sensors allowed to improve the occupancy monitoring and to have a historical record of environmental values such as temperature, humidity and light strictly connected to users’ preferences. The mobile application about renovation activities performed and residents’ indoor home conditions—BIM4Occupants—has been installed by the users and specific workshops with inhabitants were carried out for registration purposes. The BIM Management System is currently collecting sensors’ data stream and data stream between tools such as BIM4Occupants and BIMPlanner. Project monitoring and better communication among users were tested in a different workshop by applying the BIMPlanner tool in the plans and progress site operations. The functionalities of the refurbishment scenario simulation tool—BIMeaser—were tested in qualitative and quantitative design workshops respectively with the construction professionals using the two pilot sites in Italy and in Finland and with the aim of assessing the achieved time savings of using this tool compared to the manual data input process of the scenario simulation.