Energy retrofit of historical buildings: An Italian case study

The most suitable intervention for energy rehabilitation of historical buildings has to reach both the goal of the optimization of the energy saving and the preservation of the original characteristics of the building. The present work is related to refurbishment and energy rehabilitation of an historical building dating back to 15th century. The building complex under study is an ancient residential courtyard building located in Northern Italy near Verona. The strategies have been focused on the building envelope and energy supply systems respecting both the regulatory constraints imposed by preservation of historical buildings and,where possible,the current national legislation about the building energy efficiency. This result was achieved only through the identification of best solutions based on mutual compatibility and optimization of the performance of the building envelope and the HVAC systems. In the design phase,the thermal performance of the building for both winter and summer periods have been evaluated by dynamic computer simulations. It has been shown that adequate interventions focused on the building envelope and HVAC systems reduces the energy consumption in a significant way. Further,it has been shown through economical analysis that extra-costs for energy retrofit measures paid back quickly during the life span of the building. Historical buildings are characterized by unique and specific characters that could be preserved,also upgrading them to modern requirements. This study demonstrates how it is possible to intervene effectively (and correctly by the historical and architectural point of view) on the energy performance of ancient buildings. By applying innovative techniques and technologies,in fact,it is possible to achieve high energy efficiency levels,without affecting the original architectural appearance and value. The methodology presented can be an interesting case study for all those building interventions where energy,cultural and historical issues intersect.