BIM for sustainable redevelopment of a major office building in Rome

Energy efficiency represents a strategic priority in both Italian and European legislation to mitigate the energy consumption of buildings, which are significant contributors to greenhouse gas emissions. Currently, about 75% of the EU building stock is considered to be energy inefficient and requires substantial retrofitting. This study examines the energy redevelopment of a large building complex, which currently has an energy class E label. The aim is to achieve a significant improvement in energy efficiency and reduce fossil fuels usage, in line with sustainability standards. The intervention includes replacing the existing air-conditioning and heating systems with high-efficiency air-to-water heat pumps, powered by electricity generated, in part, by an integrated photovoltaic system. Through the analysis of available technological solutions and the application of a Building Information Modeling (BIM) methodology, the research proposes strategies to optimize the energy efficiency of buildings while minimizing the environmental impact and ensuring compliance with current regulations. The results highlight the effectiveness of such approaches in supporting the energy transition, with the implemented measures reducing the non-renewable energy demand from 191,684 kWh/m2/year to 76,053 kWh/m2/year. This led to a decrease in CO2 emissions of 604 tons/year, representing a 78% reduction compared to initial levels, a clear contribution toward achieving European sustainability goals.