"Soft story" buildings are multi-story buildings constructed atop a first floor with lots of open space, typically a garage.
In Oakland alone, about 1,500 soft story buildings have been identified, mostly around Lake Merrit.
The Association of Bay Area Governments says most cities like San Francisco, Oakland and Santa Clara have identified apartment buildings with garages under them, but it is unclear who will pay the $5,000-$10,000 if a retrofit is mandated.
"If we have an earthquake that happens on the Hayward Fault in the next year or two, we're in trouble; we have estimated that there are roughly 150,000 housing units that could be rendered uninhabitable," earthquake consultant Jeanne Perkins said.
So far, Fremont is the only city with a mandatory ordinance requiring owners to retrofit "soft story" apartments that are two or more stories.
