Assessment of integrated solutions for the combined energy efficiency improvement and seismic strengthening of existing URM buildings

Abstract

The European building stock is an aging infrastructure, mainly built prior to building codes. Furthermore, 65% of these buildings are located in seismic regions, which need to be both energetic and seismically retrofitted to comply with performance targets. Given this, this manuscript presents integrated constructive solutions that combine both energy efficiency improvement and seismic strengthening. The goal and novelty is to design and to evaluate one-shot, compatible, noninvasive, and complementary solutions applied to the façades of buildings with a minimum cost. To do so, different constraints have been borne in mind: the urban environment, achievable seismic and energy performance targets, and reduced construction costs. The method was applied to an old Spanish neighbourhood constructed in the 1960s. Different retrofitting packages were proposed for an unreinforced masonry case study building. A sensitivity analysis was performed to assess the effects of each configuration. A benefit/cost ratio was proposed to comparatively assess and to rank the solutions. The results of the seismoenergetic performance assessment showed that improving the behaviour of walls leads to higher benefit ratios than improving the openings. However, this latter strategy generates much lower construction costs. Integrating seismic into energetic retrofitting solutions supposes negligible additional costs but can improve the seismic behaviour of buildings by up to 240%. The optimal solution was the addition of higher ratios of steel grids and intermediate profiles in openings while adding thermal insulation in walls and renovating the window frames with PVC and standard 4/6/4 double glazing.