Evaluation of options for building refurbishment: an innovative design tool supporting decision-makers in Italy

The refurbishment and energy retrofitting of residential building stock is a crucial issue in the construction sector. In the next years, more than 60% of existing buildings could be interested by major retrofitting measures as they were built before the issuing of any Italian energy regulations. Most of these buildings need not only measures to improve the energy-efficiency standards but also a wider refurbishment program to improve the spatial quality and the architectural features. This paper shows the output of a research work aimed at the implementation of a design tool supporting decision-makers during the evaluation of different design strategies. This tool is the result of an integrated approach considering: the performances of building envelope before and after refurbishment; the environmental impact related to the use of building materials in the different retrofitting strategies; the effects on occupants’ comfort; the added value in terms of extension of living area and optimization of internal layout. The tool has been tested on pilot cases selected among the social housing complexes in the Lombardy Region, built after the Second World War. Simulations on several case studies led to the grouping of most promising refurbishment strategies according different building types, building technologies, climatic and environmental conditions.