The city of Mountain View is set to follow the example of San Francisco and Berkeley after staff last week proposed taking the first steps towards encouraging -- or forcing -- property owners to retrofit buildings in the city that are more likely to collapse in major earthquakes.
At the April 28 city council meeting on the draft budget, community development staff proposed putting $350,000 toward a study to identify all the so-called soft-story buildings in the city and what would need to be done to retrofit those buildings, and to outline potential incentives or mandates for property owners to make those building upgrades.
Soft-story buildings have structurally weak ground floors, normally wood-frame construction with a large open area often used for parking, and they are vulnerable to damage and collapse in earthquakes. The structural weakness was clear in the 1989 Loma Prieta earthquake, when soft-story buildings "pancaked" following a collapse of the first floor, according to William Strawn, public affairs director for San Francisco's Department of Building Inspection.
Mountain View's study would survey where soft-story buildings are located in the city, but it would also explore next steps. The city could create incentives for property owners to move forward on retrofitting unsafe buildings, or it could go straight into passing a city ordinance mandating property owners to have an architect or engineer inspect the building and pay for any upgrades that are identified.
"More critically, it's about what do we do about these buildings that are highly vulnerable in an earthquake," said Randy Tsuda, community development director for the city of Mountain View.
A 'substantial' number of rental units
Tsuda estimates that somewhere between 100 and 125 buildings in Mountain View have a soft-story design that may need retrofitting, which he said is a "substantial portion" of the rental housing stock in the city. A survey by San Jose State University in 2006 found 1,129 first-story apartment units in soft story buildings in Mountain View, which adds up to an estimated 2,823 residents.
Many of the homes severely damaged in the Loma Preita earthquake as well as the 1994 Northridge earthquake in Los Angeles were soft-story buildings, which prompted changes in building codes, Tsuda said. That means new soft-story buildings can still be constructed, but with very different building standards.
That doesn't help Mountain View much, considering most of the city's housing was built long ago. A study in 2009 of the city's housing stock shows 53 percent of thee homes are over 40 years old, and roughly 19 percent of the total housing is soft-story multi-family dwellings.
There's also no pressure by the state on property owners to retrofit soft-story buildings, leaving it up to individual cities. The California Health and Safety Code states that soft-story buildings can create "dangerous conditions" in an earthquake, and were responsible for "7,700 of the 16,000 housing units rendered uninhabitable by the Loma Prieta earthquake and over 34,000 of the housing units rendered uninhabitable by the Northridge earthquake."
Despite the damning evidence that soft-story buildings are unsafe in earthquakes, the health and safety code only "encourages" cities and counties to address seismic safety of soft-story residential buildings.
Property owners in Mountain View are currently not required to tell tenants whether they are living in a soft-story building that haven't had retrofitting done for earthquake safety, Tsuda said.
There was some confusion among City Council members at the April 28 meeting over why the city needed to conduct a survey itself. After all, San Jose State University had already tracked down over 1,100 apartment units in the city that are potentially unsafe.
Tsuda told the council that city staff did request that information, but were turned down after they were told the university's housing inventory was proprietary. It's not clear why the university is withholding the data from the city, Tsuda said.
"We don't even know if the people who did the study are even at San Jose State anymore," he said. "They would not release that information."
The Voice contacted members of the San Jose State University Research Foundation, but did not receive an answer by Wednesday's press deadline.
Once the funding is approved, Mountain View will be the first city in Santa Clara County to get moving on retrofitting its soft-story housing, but it will be years behind cities like San Francisco and Berkeley that have not only mapped out potentially unsafe housing, but led the way in passing ordinances mandating earthquake inspections and retrofits.
Warning signs required
In 2005, Berkeley adopted an ordinance requiring owners of soft-story buildings to submit engineering reports that include a list of structural weaknesses and ways to reinforce the building. It also required owners to let tenants know that the buildings they're living in are soft-story. In an effort to make it painfully obvious, landlords were forced to put a sign on the building entrance in plain sight that states "Earthquake Warning. This is a soft-story building with a soft, weak, or open front ground floor. You may not be safe inside or near such buildings during an earthquake."
Landlords in Berkeley have been paying anywhere from $2,000 to $10,000 per unit for the seismic retrofit work, averaging about $3,280 per unit, according to the city's Planning and Development department. Property owners are allowed to increase rents to offset the costs on a "case-by-case" basis.
San Francisco's success
Strawn said San Francisco's Mandatory Soft Story Retrofit program has been very successful so far, and as of last week all but 5 of the nearly 6,700 property owners of soft-story buildings in the city have submitted screening forms determining whether retrofit work is needed. As of May 5, he said about 50 retrofit jobs have already been completed.
"The initial part of the program has definitely been successful," Strawn said. "The fact that we literally have 5 of 6,700 who haven't responded is amazing, really."
The program did little to pit tenants and landlords against one another, he said, and members of the San Francisco Apartment Association, many of whom own soft-story buildings, were supportive of both the legislation and implementation. All the costs associated with the retrofit work can be passed onto tenants through rent increases.
Getting a head-start relative to the rest of the county on retrofit work might be a good idea in light of recent data that shows the chance of a major earthquake in the Bay Area is higher than previously estimated. The chance of an earthquake with a magnitude of 6.7 or greater in the next 30 years is now pinned at 72 percent, according to Andrew Michael, a research geophysicist at U.S. Geological Survey's Earthquake Science Center in Menlo Park. That's up from the 63 percent probability found in a 2008 study.
Part of the reason for the increase, Michael said, is that research now analyzes faults more as a "network" where quakes can jump from fault to fault, rather than determining isolated earthquake probabilities for the San Andreas and Hayward faults. He said earthquakes involving multiple fault lines can produce longer and larger earthquakes, causing widespread and devastating earthquakes like Loma Prieta.
The higher probability may not prompt major changes in building retrofitting programs, Michael said, but it's certainly a reminder that earthquake readiness remains a key issue for residents in the Bay Area.
"The data really highlights that we should be doing something," Michael said.