What Factors Influence the Success of Soft Story Retrofit Programs? The Example of San Francisco’s Program

In the event of an earthquake, one of the types of structures that is most susceptible to collapse is soft-story buildings (Association of Bay Area Governments [ABAG], 2016). Built before current regulation and codes were enacted, a soft-story residential building is a building that has commercial space or open parking on the first floor, with units built above it (ABAG, 2016). The first floor has a weak structure and the units above the first floor weigh heavily on it (Arroyo, 2019). Due to their building structure, these properties may sway or collapse during an earthquake, ultimately causing fatalities and damage (ABAG, 2016). To prevent this from occurring, many cities have established programs to require property owners to retrofit their soft-story buildings (ABAG, 2016). The timing and intensity of the next earthquake are unpredictable, but to prepare for the next event, the City of San Francisco has created the Mandatory Soft Story Program to retrofit the city’s soft-story buildings. The following research question guides this study: In San Francisco, what factors influence owners’ decisions to retrofit their buildings? How can this knowledge help other cities to develop effective retrofit programs