Energy efficiency improvements in historic buildings: analysis of a case study in central Italy

The energy requalification strategies of buildings commonly involve the adoption of improvement interventions regarding the thermal features of the building envelope and the efficiency of the HVAC system. Furthermore, in historic buildings various architectonic, town planning and landscape constraints often reduce the number of solutions to be adopted. The energy requirements prescribed by Italian legislation have recently been extended to historic public buildings too. Taking into account the indications of the current Italian law, the authors carried out an energy efficiency audit and upgrade of “Palazzo Valignani”, an important architectural building located in Chieti, a small town in central Italy, currently under structural refurbishment due to the earthquake that hit the Abruzzo region in 2009. The authors carried out an analysis in dynamic conditions using DesignBuilder software concerning the energy performance of the building with the aim to define the best energy efficiency improvements, by considering the thermal envelope performance, the HVAC system efficiency, the thermo-hygrometric comfort and the economic point of view. The results of this study show that, despite the architectural and historic restrictions, it is possible to achieve significant improvements in the energy efficiency of historic buildings in full compliance with current energy legislation in Italy.