Retrofitting of the Italian precast industrial building stock. LCA analysis as decision-making tool

The challenging European goal concerns the achievement of a carbon-free economy by 2050 must necessarily consider the improvement of the construction sector along with the redevelopment of the existing buildings. In fact, according to a European report concerning existing buildings, 80% of the built environment will remain the same by 2050. Nowadays buildings are responsible for 30% of the global final energy consumption and 37% of global energy and process emissions. As regards industrial buildings, they account for 33% of global final energy demand. The research aims to define some effective retrofitting measures to be applied in the existing Italian industrial facilities to improve their both energy and environmental performance. Several redevelopment scenarios and their possible combinations related to external envelope technological solutions and systems are analysed. The different interventions are applied to an existing Italian industrial building chosen as a case study and are compared by Life Cycle Assessment (LCA) analysis considering different environmental indexes (GWP, AP, PERT and PENRT). The calculation of the primary energy demand is also performed. Phase B6 accounts for about 80% of the whole environmental impact calculated considering 20 years as building lifetime. The redevelopment scenarios that foresee the intervention on the external envelope are the most impactful ones in terms of the production phase (A1-A3). Those related to the existing roof are characterised by a significant impact due to the demolition, disposal and landfill of finishing panels made of asbestos. The configurations that include the substitution of the existing heating system with an air-to-air heat pump coupled with renewables to produce electrical energy on-site are the most advantageous ones. The latter make the industrial building carbon-zero thanks to the considerable amount of surplus electrical energy produced on-site. In this case, phase D mostly recovers the environmental impact of the whole life cycle considering the different indexes.