Weights of embodied energy and carbon emissions in an energy retrofit of the building envelope: Assessment for a Mediterranean residential building

Europe’s commitment to reduce energy consumption and CO2 emissions by 2050 led to a proposal to amend the EPBD in December 2021. This proposal introduces the environmental footprint assessment for new buildings involving all phases of their life cycle. The life cycle approach, however, could provide valid suggestions and results even if applied to energy renovation interventions. In this study, the LCA methodology - according to the variant cradle-to-gate with options - is used to investigate the energy and emissions consumed and produced for the energy-oriented retrofit of both opaque and transparent building envelope of a residential building, in the Mediterranean area. The analysis shows that the solutions that allow maximum energy savings in the operational phase of the building differ from those characterized by minimal energy impact from a life cycle perspective. At the same time, however, the latter enable an acceptable operational energy saving and a higher total reduction of energy demands. In detail, the solution that allows maximum energy savings in the operational phase, equal to about 39.4%, has a weight of the embedded energy of 7.1%. The solution with the minimum weight of the incorporated energy, equal to about 5.5%, allows an operating energy saving of 39.1%.