Active House and user-friendly visualization of sensors’ monitored data: VELUXlab, a real cognitive and smart NZEB prototype

European standards had already set Nearly Zero Energy Buildings (NZEB) as the current and mandatory goal for the construction market. Thus, several design strategies have been developed, in order to define the best practices towards NZEB targets: high performances of construction components, integrated with high energy-efficiency solutions for building systems. The Active House Vision and evaluative approach on buildings summarize the current protocols, accounting the three principles of Comfort, Energy and Environment to parametrically design and assess buildings until their "as-built" status. However, at that point of the design process, this evaluation relies mainly on design simulations, which do not properly consider the occupants' component, resulting in a gap between forecast and real performances. Since predictive models of users-building interactions are underway, the paper focuses on the building operation stage of existing and validated NZEBuildings, addressing the performance-gap as related to the final users' mismanagement of the building system (envelope and installations). Referring to cognitive buildings as sensors-equipped and smart Active Houses, the method proposes a user-friendly visualization of (big) real-data as a possible solution for the final-user training and awareness. This approach has been applied to the case study of VELUXlab, a real building prototype of Politecnico di Milano, already validated as the first Italian NZEB inside a university campus and "as-built" Active House. The outcomes of the paper enhance the potentials of the current knowledge and design practice to achieve a sustainable and healthier built environment, looking at the future but working today.