Opportunities for understanding and reducing risk in the housing sector

In order to evaluate the risk in residential buildings, we need to develop and promote standard guidelines for seismic safety assessment, including consideration of “as is” condition of the buildings and not just the “as designed” structural deficiencies. In addition, guidelines for structural seismic retrofitting and nonstructural improvements of residential buildings need to be developed for engineers, homeowners, and municipalities. The process of quality control and approval of safety assessments is key and should be streamlined. Opportunities should also be taken to integrate seismic structural assessment and upgrade with any ongoing programs for building improvements (e.g., energy efficiency improvements). In order to solve the issue of seismic safety in existing buildings, researchers and engineers have started to come up with creative and cost-efficient solutions, such as addition and sale of floors in large panel buildings to finance structural retrofit of the buildings. Many of the European countries are currently making sizable investments in improving energy efficiency, but in seismic countries, any solution that addresses only energy efficiency can turn out to be futile if an earthquake occurs. Interventions for energy efficiency and seismic retrofitting typically exist separately, and they can lead to high occupant disturbance, long intervention times, and high costs. There is, however, an opportunity to use new innovative solutions that aim to combine energy efficiency and seismic upgrade in an integrated way in order to overcome the abovementioned barriers. One possible solution is the external addition of prefabricated structural cross-laminated timber (CLT) panels, which improve global seismic safety. The structural CLT panels are combined with other nonstructural, customizable, prefabricated panels made up of a light wooden structure. Both panels are coupled with insulating materials to increase energy efficiency. Such an approach uses external intervention with prefabricated components, which optimizes cost, helps avoid relocation of the residents, and reduces construction time.