Energy-Efficient Smart Building in the Smart City: a way to regenerate and value the existing building heritage

Over the last few years there have been several attempts to define the Smart City, a concept that has only recently reached critical maturity: it has changed, in fact, from a digital city to a city that ensures a better quality of life for citizens. Moreover, if in the industrial sphere we focus on the immateriality of ICT and in the humanities on their social aspect, in the civil sphere there is the awareness that it is not possible to disregard the "physical reality" of the city and therefore we will talk about buildings, transport and infrastructure, of the interactions between them, of the overall efficiency of the city system. Current cities must face and solve numerous problems and criticalities: the rapid growth of the population, the scarcity of water and energy resources, the exploitation of the soil, environmental pollution, just to list a few. The "Cities of Tomorrow" must be ecological, efficient and respectful of the building, social and environmental heritage; they will ensure a high quality of life in terms of well-being, social cohesion, integration and equity. The buildings, refurbished to generate value, became sustainable, interactive and energy producing nodes