Disaster risks are increasing, threatening communities and their housing. As a result, we need to implement construction practices that improve the safety of housing in future hazards. Household and builders’ perceptions of housing safety motivate construction practices; however, we have limited knowledge of whether perceptions of housing safety align or misalign with engineering recommendations. Identifying and addressing misalignments can help target training to address unsafe practices and improve housing safety.   

Thus, this project characterized housing safety perceptions in multi-hazard environments, conducted engineering performance assessments to evaluate structural safety, and identified misalignments between perceptions and engineering assessments that motivate unsafe practices in the Philippines and Puerto Rico. We then designed, piloted, and evaluated a technical construction capacity-building program.  

In the Philippines, we explored households’ perceptions of housing safety in ten communities, analyzed the structural performance of housing in wind events, and then identified misalignments. Most households expected their shelter to be damaged in a future typhoon. Our wind performance assessment of twelve post-disaster housing designs found that roof coverings would detach, in even a Category 2 event, and that some designs also had risk of wall collapse in future storms. While household perceptions were well-aligned with engineering assessments at the component level, we found that many households lacked a systems understanding of house, or how modifications made to one component would affect the performance of other components. For example, we found that households may strengthen their roofs without taking appropriate measures to strengthen their walls to support the roof-wall system. Improving this understanding is important, as our key recommendation to improve safety was to ensure adequate wall capacity and a continuous load path to prevent catastrophic wall racking failure.   

In Puerto Rico, we focused on understanding perceptions of housing safety among builders in the informal construction sector. We compared individuals’ perceptions, preferences, and priorities before and after the 2019-2020 earthquakes in Puerto Rico, a less frequent disaster compared to hurricanes. A survey identified perceptions of housing safety that motivated ongoing design and construction practices and reasons for these practices. We performed wind and seismic assessments of typical housing designs, which revealed structural vulnerabilities and feasible recommendations to increase the safety of both newly constructed and retrofitted housing. For instance, the wind assessments recommended that builders should prioritize strengthening the roof-to-wall connections with hurricane straps to reduce the risk of catastrophic failure. Then, we compared the perceptions captured in our survey of housing safety perceptions and structural engineering assessments to identify misalignments. These included builders not using hurricane straps to secure key wood-frame roof connections and instead prioritizing methods of securing the metal roof panels, and builders not recognizing the increased safety of housing built through confined rather than infill masonry methods.  

In the final stage of work, we drew from the misalignments to design a capacity-building approach to effectively share technical recommendations about hurricane strap appropriate use to builders in Puerto Rico. We partnered with a locally-based organizations to collaboratively design, pilot, and evaluate this capacity-building approach, interviewed individuals following the approach to elicit their perspectives, and evaluated their reported changes to self-efficacy and knowledge of mitigation measure efficacy. For example, interviewees indicated they wanted to learn more about their fastener options for hurricane straps, and we added information and demonstration materials to the approach. We also used this pilot to implement two additional capacity-building workshops.   

Intellectual Merit: With this project, we advanced understanding of multi-hazard housing safety by characterizing perceptions that are motivating housing design and construction practices, evaluating the structural performance of donor-built housing in the Philippines and informally constructed housing in Puerto Rico, and identifying how these perceptions and engineering assessments misalign and lead to unsafe practices. The structural assessments provided new insight into the multi-hazard safety of donor-built and informally constructed housing in the Philippines and Puerto Rico and recommended modifications to improve housing safety. The method of identifying misalignments as a basis to inform capacity building approaches will help reduce disaster risk.  

Broader Impacts: Our project holistically aimed to increase community capabilities to build safer housing to ultimately reduce disaster risk. This project has led to the development of several interdisciplinary partnerships between the university and non-governmental organizations, diaspora groups, government agencies, and industry groups in the Philippines and Puerto Rico. With this project, we also give voice to local builders, residents, grassroots groups, hardware store employees, and others in Puerto Rico and incorporate their perspectives by co-creating a capacity-building approach that recognizes their needs, values, and available resources. The wind and seismic structural assessments provide feasible science-based recommendations to improve the multi-hazard safety of donor-built and informally constructed housing.