Methodological Approach to the Energy Analysis of Unconstrained Historical Buildings

The goal set by the EU of quasi-zero energy buildings is not easy to reach for a country like Italy, as it holds a wide number of UNESCO sites and most of them are entire historical old towns. This paper focuses on the problem of the improvement of energy performance of historical Italian architecture through 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 TS 11300-Part1, which indicates how to evaluate the energy consumptions. The calculations were performed only on the building envelope, based on passive solutions and alternatives. Four passive strategies were examined and applied based on the location of the building and the non-alteration of the structure and the landscape. The obtained results impacted positively on the energy performance of the building: the annual energy saving reached a maximum value of 25%. This work shows how it is possible to improve the energy performance of an existing building achieving a significant energy saving with the respect of the building architecture, shape, function and the surrounding landscape.