Soft-story buildings refers to older, wood-frame multi-story buildings that became popular with developers in the fifties and sixties. Soft-story designs became wildly popular in California following World War II and the boom of car ownership. The designs proved to be efficient offering residents an economical solution to housing with the added benefit of tuck-under parking. The wide openings and lack of partition walls on the ground level leaves, soft-story apartments structurally vulnerable in the event of an earthquake.
Due to the large openings of the garage doors and open parking stalls, the building becomes weak, flexible, or otherwise vulnerable. Buildings built before current building codes have a tendency to collapse with enough shake and shock. Soft-story buildings were affected during the Loma Prieta earthquake of 89 and the Northridge earthquake of 94. Some sustained major damage and there were incidents of apartments collapsing.
Approximately 140,000 units in 18,000 soft-story apartments exist in the Bay Area. In 2003, experts estimated that soft story buildings will account for two-thirds of uninhabitable in a major Hayward fault earthquake. In 1989, half of the housing lost was caused by the Loma Prieta earthquake. Soft-story apartments still account for a significant portion of residential units putting both tenants and landlords at risk. Protecting soft story buildings from total collapse can both save lives and investment.
San Francisco and Berkeley have already recognized soft-story buildings as a problem and have passed mandatory retrofit ordinances. I suspect Oakland, San Leandro, and the South Bay will soon follow suit. Seismic retrofits are important in potentially saving lives and your investment in an apartment, yet they place a significant financial burden on property owners and impacts the profitability of an apartment. Municipalities will have to balance safety and costs when implementing policies in future soft-story ordinances. Particularly in rent control cities such as Oakland, retrofit projects that can cost anywhere from $50,000 to $200,000 may be prove to be challenging for private investors.