Multi-criteria decision-making application for sustainable building renovation

The Life Cycle Thinking (LCT) approach offers a holistic perspective for designing sustainable retrofitting strategies, by minimising environmental impact throughout all phases of the building's life cycle, while also addressing economic and social issues. This work presents a multi-criteria decision-making (MCDM) application aimed at identifying the best retrofitting strategy for a building, considering economic, environmental, and social aspects, including earthquake-induced impacts. The case-study building is an existing reinforced concrete (RC) structure built in 1970 in Northern Italy, which is analysed and assessed in its as-built configuration, as well as in four integrated retrofitting scenarios, implying the adoption of new RC walls, steel walls, steel diagrid, and timber shell, respectively. Some of these strategies were designed according to LCT principles, and one of the aims of this study is to demonstrate the advantages of such solutions also in terms of seismic risk protection. The seismic assessment of the configurations is carried out through the FEMA P-58 approach. The results are compared in terms of the expected economic, environmental, and social impacts, leading to the identification of the timber shell solution as the best strategy.