Double layer glass façade in the refurbishment and architectural renewal of existing buildings in Italy”

The aim of this paper is to assess the use of an intelligent glass envelope in the refurbishment of existing buildings in Italy in order to fit their energetic performance considering Mediterranean climate inputs. With the new European and Italian regulations on energy efficiency of buildings, envelopes are not only forced to respect heat transmission limits (e.g. U value) and to improve their thermal insulation, but also to use and receive benefits from environmental input such as passive solar gains. Comparing to the North European solutions, a glass envelope seems not to be the most suitable solution for a Mediterranean climate, mainly due to the great incidence of solar gains and the risks of overheating during summer season. Examples presented in this paper indicates how double skin glass façades, that are commonly used in new constructions where the concept starts from a low environmental impact, can be also employed in the refurbishment of existing buildings, which is the main challenge for the global reduction of CO2. An overview on the main technical of intervention can indicate to architects and planners the weakness/strength points to take in consideration in the use of a double layer glass façade in a Mediterranean climate in order to reduce the overall energy balance.