Social housing retrofit towards energy efficiency thresholds extensible on public housing in Italy

In European countries there is a large difference with respect to the size of the building available for rent from social institutions. The country with the largest area for social rent is the Netherlands, with a percentage of 35%. In general, it can be seen that Northern and Western European countries have a social housing stock greater than the one of the countries in the Mediterranean area. During the transition process from communist regimes to market economy Eastern European countries lost a substantial part of their social housing stock due to mass privatization, although exceptions such as Czech Republic and Poland exist. In this context, also social housing stock with respect to total new construction varies widely from country to country. The stock of social housing building in Italy decreased in the last years from 1.4 million to 940,000 residential units, due to a privatization policy implemented from 1993 to 2006. It can be clearly understood that there is a consistent building stock which is in a critical condition from several points of views, such as energy consumption, maintenance, inadequacy of size and facilities of the dwellings, barriers to accessibility. Refurbishment of social housing stock has to consider multiple dimensions at once and to face these inadequate conditions. The study presented, based on a project which involved a whole re-design of a social housing building improving accessibility and indoor space distribution and sizing, is focused specifically on the energy performance improvement achievable through the envelope and technical system retrofitting. The approach adopted can be applied to several similar projects on social housing stock at the building and urban neighborhood scale. The evaluation of the performance through dynamic simulation and a transparent methodology for data analysis is crucial to realistically evaluate the outcome of such projects and to disseminate them for effective refurbishment policies in the social housing stock.