L'innovazione nell'involucro edilizio: dal concetto di "isolamento" a quello di "integrazione e multifunzionalità"

The building envelope has always been considered a key element to guarantee indoor comfort and energy efficiency. Nevertheless, in the past, and to certain extent still today, the main aim was the improvement of the thermal insulation properties. This strategy was a winning one as long as the designers and users focused their attention only on the heating demand. However, when the overall energy demand (heating, cooling, lighting) and ZEB (Zero Energy Buildings) started to be considered, this approach showed all its limitations. Nowadays, in order to fulfil all the desired goals, the envelope has to perform like a dynamic and multifunctional skin and it must provide an active behaviour. The building envelope must be able to manage and controls energy and mass flows, to store and release energy and to become a net energy source instead of a net energy demand issue. In this paper the technological evolution of the building envelope will be discussed, ranging from traditional to innovative components. Moreover, an overview of the re-search trends and outcomes of the last decade will be analysed, providing examples of applications of new technologies and a critical analysis of the issues related to the use and design of such components.