A multi-step approach to assess the lifecycle economic impact of seismic risk on optimal energy retrofit

Most European buildings built before 1980s were constructed without any design concernfor energy efficiency and environmental sustainability. In addition to this issue, over the last decades,the essential need of safer buildings has progressively attracted the interest of scientific communityand government institutions. However, the strong interaction between energy and structural aspectsin building retrofit design has never been handled via robust and reliable approaches. The presentstudy explores this knowledge gap by introducing a novel multi-step approach that addresses theretrofit of existing buildings by integrating energy, structural and economic aspects. To this end,a multi-stage energy optimization is carried out by implementing a genetic algorithm and a smartresearch strategy. Thus, the cost-optimal energy retrofit solution is identified and the impact ofthe expected economic losses due to seismic damage is assessed throughout the building lifecycle.The methodology is applied to a multi-story residential building, considering the effects of twodifferent building locations, namely Milan and Norcia. These latter are characterized by similarclimatic conditions but by a different level of seismic risk, which is higher for Norcia. The outcomesshow that the estimated seismic economic losses associated with the energy retrofit solutions arestrongly affected by the building location. Thus, the selection of the optimal energy retrofit measuresshould be related to the building structural behavior in order to achieve reliable economic andsustainability benefits.