While much of the city's real estate market is soaring thanks to a tech boom that has attracted giants such as Twitter to the city's downtown, many apartment owners are limited in what they can charge because most private units are rent controlled, said Charley Goss, government and community affairs coordinator of the San Francisco Apartment Association. That is often the case for owners of the buildings most likely to be affected in the Mission, Western Addition and Marina neighborhoods, he added.
"The owners that can best shoulder the costs probably would have rented their apartments recently, so would be getting their full market value," he said. "Those who haven't will likely have to get a refinance on their building or get a second mortgage or a loan."
Robert Link, who owns a small property management firm, said he would have to spend about $70,000 to retrofit an Edwardian multi-unit building he owns in the inner Richmond.
"The ultimate beneficiary here is not the property owners but San Francisco tenants, because doing these upgrades will preserve rent-controlled buildings," he said. "Really what this requires is managing tenants' needs and expectations of the process, and giving them advance notice of as much as you can of the work to be done."
San Francisco's rents have been climbing in the last several years, leveling off only recently as experts say the market has approached saturation.
Rents average $2,175 for a one-bedroom, one-bathroom apartment, according to RealFacts, a Novato consulting group that tracks apartment complexes with 50 or more units.
After the Loma Prieta earthquake in 1989, San Francisco mandated retrofitting of unreinforced masonry, or brick, buildings. But the effort to bolster soft-story apartment buildings was a tougher sell, and was opposed by owners and tenants rights advocates concerned over the rent increases.
Seismologists predict that a significant earthquake in the region — two to three times as strong as Loma Prieta — is likely to occur within the next 30 years.
"When an earthquake happens, these buildings will be vulnerable. If we're going to be able to recover, this is a necessary step," Goss said.