INSTRUMENTS FOR THE CALCULATION OF ENERGY PERFORMANCE IN HISTORICAL BUILDINGS. LIMITS OF APPLICABILITY AND TUNING PROPOSAL

This study¹ focuses on the improvement of the energy efficiency of the building with historical and testimonial value, with particular attention to monumental buildings. A distinctive feature of this type of buildings is that one cannot identify generic energy performance or guidelines for the energetic retrofit. The monumental historic buildings generally are not integral part of the urban fabric, since they often stand out, rising, free on every side, in the space assigned to them.. For this reason the design of the requalification cannot just refer to the relevant legislation developed for existing recent building, since it leads to a calculation model appropriate to the energy performance measurement of a mostly residential contemporary building structure. This requires a preliminary building analysis, different from the one provided for the rest of the existing not historical building. This analysis needs to start from a knowledge as precise as possible of the energy behaviour and environmental impact of these buildings. The issue of improving the energy efficiency of historic buildings has attracted the interest of various stakeholders in the construction industry (research agencies, planners, private companies and public administrations). They recognize the need to monitor the energy behaviour of historical buildings with artistic value as well as the one of existing not historical assets. This new interest for this subject spawns from the large number of historic buildings in our national territory², and in Europe, since they constitute a significant fraction of the buildings currently in use. Many institutions and public offices (police stations, municipalities and provinces, courts, schools, theaters, museums, etc.) and a large number of residences are located in historic buildings that have a strategic role for the image and the life of the community. Such heritage must find a role in the process of improving the technical-performance of our real estate, to be able to meet the new demand for comfort and safety. When we intervene to restore, and conserve, an historical building we should take the opportunity to promote its cultural value. We can do so only by introducing in the building new features or new technological systems able to extend its current lifecycle, or to initiate a new, according to the currently regulatory standards.. In addition to the regulatory standards of safety, in particularly regarding earthquake safety, buildings must also respond to the requirements for well-being of people and artwork housed within them, which would allow them to be, or to be again, a functional container, not just a standalone museum.. All this is, moreover, strongly connected to the new European directives that impose by 2014 (Directive 2012/27/UE) the obligation to upgrading the energy efficiency of 3% of the surface of the properties owned by the central government.