Drawing from local, multi-hazard safety perceptions and engineering assessments for safer housing

Disasters are growing more frequent and severe, threatening communities and their housing. Most of the world’s housing is constructed informally, where residents hire builders or self-build to meet their needs given available resources. Without adhering to formal regulatory processes, each resident and builder’s housing safety perceptions determines their design and construction decisions and, ultimately, housing safety. In multi-hazard regions, builders aiming to construct housing in one, common hazard type may inadvertently create structural vulnerabilities for another hazard the housing is also exposed to. Given the prominence of this informally constructed housing worldwide, I investigated multi-hazard housing safety perceptions and opportunities to build technical construction capacity in Puerto Rico, a US Caribbean Island exposed to hurricanes and earthquakes. I began this investigation by comparing housing safety perceptions before and after Puerto Rico’s first series of severe earthquakes for over a century. After the earthquakes, I found residents and builders had decreased fatalism and trust in the informal construction sector and were more willing to seek engineering guidance on hazard-resistant construction. Next, I surveyed those involved in informal housing construction to assess their perceptions of safe and unsafe practices, finding the influence of construction experience on these perceptions as well as fatalism associated with wood housing in hurricanes and concrete housing in earthquakes. Survey respondents largely reported that most unsafe practices are rooted in technical construction capacity, or technical knowledge on the topic, rather than resource constraints alone. I compared these perceptions with recommendations from wind and seismic engineering assessments to identify four misalignments rooted in technical construction capacity limitations, one of which was builders not perceiving hurricane straps to be important to use at key wood-frame roof connections. Lastly, I designed, piloted, and evaluated a capacity-building approach directed at the appropriate use of hurricane straps for wood-frame roof mitigation. These results deepen understanding of the multi-hazard housing safety perceptions that motivate ongoing informal construction practices, what influences those perceptions, how those perceptions compare to engineering assessments, and how to build self-efficacy and understanding of mitigation measures through capacity-building. Practically, findings direct organizations to focus areas for capacity-building to reduce disaster risk.