Integrated Approach to Assess the Energy and Environmental Payback Time of Buildings Refurbishment: A Case Study

The design of nZEB buildings, as well as the implementationof retrofit interventions in existing structures, are essentialtools for reducing energy consumption in buildingsand increasing decarbonization of the building sector. Todescribe the effectiveness of a retrofit intervention, in additionto the analysis of the benefits in terms of costs andenergy savings, an environmental analysis should also beperformed, introducing various indicators, such as energyand environmental payback times. In this article, we considereda residential building located in Montemarcello(Liguria, North-west of Italy) that had been subjected to arefurbishment and an expansion, with the aim of evaluatingthe energy and carbon savings achievable due to theinterventions carried out. The life cycle analysis approachwas applied to calculate the environmental payback times.The main purpose of this work is the application of an integratedapproach to assess the economic, energetic andenvironmental convenience of retrofit interventions duringthe entire life cycle of the building, underlining the importanceof considering LCA and environmental aspectsto achieve decarbonisation of the construction sector. Theresults show that energy and environmental paybacktimes are lower than the useful life of the building and ofits components, and that LCA proves to be a strategicmethodology for studying the problems deriving fromglobal warming and energy supply in the building sector.