Achieving nZEB goal through prefabricated buildings: Case study in Italy

Building energy consumption constitutes a significant share of global energy demand. This study examines how a prefabricated building, often subject to challenges in maintaining comfort, can meet the nearly zero-energy building (nZEB) standards in Italy. This study fills the gap in the literature on prefabricated buildings that meet nZEB standards, proposing an innovative approach that integrates vacuum insulated panels (VIP) and photovoltaic systems with storage to optimize energy efficiency and thermal comfort. The paper examines an existing prefabricated building and assesses the most effective solutions to implement, along with their respective impacts on comfort and energy consumption. The model of the building is developed in EnergyPlus and verified with experimental data. The results indicate significant energy savings, demonstrating the feasibility of prefabricated buildings in achieving nZEB goals. In particular, if the building is equipped with solar shading, controlled mechanical ventilation, free cooling, and vacuum insulated panels, the thermal savings is 60 %. If the maximum photovoltaic power possible is installed on the roof the energy demand coverage is 63 %, which increases to 95 % with a storage system with a nominal capacity of 10 kWh. This paper aims to provide insights for designers, researchers and policymakers by exposing the potential for prefabricated solutions to meet stringent energy standards and promote sustainability in the construction industry.