A holistic approach for energy renovation of the town hall building in a typical small city of southern Italy

The reduction of buildings energy demand represents one of the main goals in developed countries in order to achieve a sustainable future. In Italy a significant number of public administration offices are located in historical buildings, especially in small provincial towns. In this paper the analysis of the energy and environmental effects deriving from the plant renovation of the Palazzo San Giorgio, the building offices of the municipality of Campobasso (Southern Italy), is carried out. The simulation model of the building-plant system has been implemented with the TRNSYS software using data collected in the survey campaign. It has been calibrated on the basis of the billed electricity and gas consumption and then, further used to evaluate the reduction of the building primary energy demands and CO2 emissions deriving from some non-invasive energy refurbishment measures: led lighting, thermostatic valves, cogeneration system and photovoltaic plant. The latter was considered in two variants: the first one provides a system completely integrated into the roof, the second one high efficiency non-integrated panels. The interventions have been evaluated both individually and combined. A primary energy saving of about 47% and a reduction in CO2 emissions of 73% are obtained with the best combined renovation action.