Integrated reduction of economic and environmental impacts via optimal seismic and energy retrofitting

A life cycle framework for an integrated classification scheme for buildings based on economic and environmental impacts and the identification of optimal retrofitting solutions aimed at improving both seismic and energy performances and limiting those impacts is presented through a parametric application on a reinforced concrete (RC) frame building. Such framework includes the economic and environmental contributions of different building life cycle phases, comprising operational energy consumption, earthquake-induced damage repair activities and potential retrofitting interventions, together with the other phases traditionally included in Life Cycle Assessments (LCAs). Eight retrofitting solutions, including sole energy refurbishments, pure structural strengthening techniques, and coupled interventions that target both objectives, are investigated for the case-study building. Each retrofitting solution produces different outcomes in terms of post-retrofit costs and environmental impacts, depending on its effectiveness in terms of seismic strengthening and/or energy efficiency improvement, measured through seismic loss and energy performance assessments, and on the building-specific architectural and structural characteristics. Those monetary and environmental parameters evaluated through the post-retrofit building’s life are thus indicated as meaningful performance metrics in order to assess the optimal renovation strategy for the building under scrutiny, depending on the climatic conditions and seismic hazard at the building site. The payback period of each retrofit investment and the average annual loss of human life associated to each retrofitting configuration are suggested as additional decision-making parameters to support the process of identifying the optimal renovation strategy for the building, as well as developing an integrated classification system. The application of the framework to an existing school building aims at demonstrating its applicability to any building of interest, performing each module through the procedure preferred by the user, and the possibility to extent it to any other kind of hazard. Its application to other building typologies is also strongly envisaged, with a view to investigate the potential of further developing the proposed integrated building classification framework, based on life cycle costs and emissions.