Methodological approach to the energy analysis of unconstrained historical buildings.

The EU gives great importance to the design of new high performance buildings to achieve the goal of the zero energy buildings. This target must be evaluated with attention in Italy, as it holds the record of the countries with more UNESCO sites in the World and at least the half of them are historical old towns or medieval villages. This paper focuseson the problem of the improvement of the energy performances of historic Italian buildings. The goal is to demonstrate how to achieve significant energy savings with simple interventions that respect the building without changing its shape and structure. The work starts from an energy analysis of a building located in the historic center of Tivoli, a town close to Rome. The analysis follows the recommendations of the UNI 11300-Part1, which indicates the evaluation of the energy consumption adapted to final users. The energy calculation was performed only on the building envelope. Four passive strategies of energy saving interventions were evaluated, based on the location of the building and on the non- alteration of the structure and the landscape. The results obtained after the application of the interventions impacts positively on the energy performance of the building: the annual energy saving reaches a maximum value of 25%. Therefore the work shows how it is possible to improve the energy performance of the Italian historical and architectural heritage achieving a significant energy saving with the respect of the building and the surrounding landscape.