by Jodi Summers
Get ready for some major chaos and expense. According to a City report, more than 2,200 buildings in Santa Monica may be vulnerable to collapse or major damage during an earthquake, including more than 1,800 soft-story buildings, 220 brick buildings, 73 concrete buildings and 71 steel-frame buildings.
The report concluded, “many buildings continue to be at risk and it is necessary to update these standards and establish a program to ensure compliance.”
The notices will go out in waves. Santa Monica will issue notices to the owners of approximately 200 brick buildings in May. By July, owners of “soft story” apartment buildings, where one or more units sit over open parking, will get their notices. By the end of 2017, an additional 510 buildings will receive notices. The last 900 buildings, which consist entirely of “soft story” apartment buildings, will get their notices to begin inspections in 2018.
As many as 80% of those properties are “soft story” apartment buildings constructed in the 1950s and 1960s. Studies have shown that “soft story” apartments buildings with units sitting over a carport may be vulnerable to collapse during significant seismic shaking. Many of those apartments lack significant support and could collapse because the first floor is too weak to support upper floors. Sometimes called “dingbats,” such buildings were popular in Southern California as economical housing in the post WWII building boom. Then the realized that ground floor carports and garages are not necessarily sturdy enough to hold up the stories above them during the shaking of a quake.
That was the case in Northridge during the 1994 earthquake, when 16 people died after their apartment building collapsed.
Despite being 14 miles from the epicenter, the 6.7-magnitude Northridge Earthquake hit Santa Monica unusually hard, mostly because of the city’s soft soil and older housing stock, experts believe. More than 1,600 housing units were damaged or lost, or roughly 5% of the housing stock. A 2004 report by the California Policy Research Center put the cost at repair at $70 million.
In the wake of the 1994 Northridge Earthquake, the Council required building owners to retrofit their buildings to updated standards, and many did – some passing on the costs of the retrofit to tenants. While owners of rent-controlled units had to prove they met requirements in order to raise rents, there was no formal enforcement effort for other structures. As a result, the city admits compliance was essentially voluntary.
2017 saw the release of Santa Monica’s list of buildings they consider “seismically vulnerable.” City staff has created a staggered structure for completing the retrofits. Unreinforced masonry, or brick, buildings have only two years to complete their retrofits because they are at greatest risk of collapse during a major earthquake. Steel moment frame structures have two decades to finish the work.
The report recommends that the City impose a more “robust” mandatory retrofit law, acknowledging the original ordinance hadn’t been properly enforced.
“There were mandatory efforts after the 1994 earthquake but they didn’t get done for whatever reason,” noted Councilmember Sue Himmelrich during the council discussion of the new ordinance. “It’s really important that we carry through with this program.”
The City is a hurry to retrofit concrete and brick buildings first because they have the biggest risk of collapse during a major earthquake. Owners of “unreinforced masonry buildings” – often made out of bricks – will have two years to get a permit and retrofit under the new ordinance. Soft-story building owners will have 72 months to finish the job.
The report has identified 900 two-story apartment houses with up to seven units and 300 more apartment buildings with 15 units or more. According the city’s top building official, Ron Takiguchi, “soft story” apartment retrofits should cost between $5,000 to $10,000 per unit and between $50 to $100 per square foot for steel and concrete buildings.
Then there are the more difficult buildings, where retrofits put them at odds with other city ordinances. Take the need to create larger columns to support apartment buildings with soft story construction. This may eliminate some of the valuable parking spaces underneath their units. The City is considering streamlining the appeals process for buildings where retrofitting creates issues. Councilmembers stressed that safety during an earthquake may take priority over other requirements.
Both tenant and owner groups acknowledge that the retrofits need to be completed. They are hoping the City will find financial aid options for these retrofits, including low-interest loans, permit fee waivers and tax breaks.
Looking at the big picture, experts say tens of thousands of buildings in Southern California are at risk in an earthquake. A U.S. Geological Survey simulation of a magnitude 7.8 quake on the San Andreas fault in Southern California projected that 1,500 buildings would collapse, and 300,000 more would suffer serious damage.
At least one fault line City officials consider active runs the length of Santa Monica and the city is near many others. Santa Monica’s coastline and some parts in its northern section are prone to liquefaction during earthquakes.
Los Angeles implemented on of the broadest and strongest retrofitting laws in November 2105. A much grander undertaking, L.A.’s ordinance includes as many as 13,500 “soft story” buildings and 1,500 potentially “brittle-to-the-breaking-point concrete buildings,” in addition to found that 70 “non-ductile concrete” buildings and 80 “steel moment frame” buildings are at risk in the event of an earthquake.
San Francisco’s law doesn’t include concrete buildings and affects a third as many buildings.
Also under consideration – Santa Monica and West Hollywood may require inspections and repairs of steel buildings. It was discovered that during the 1994 Northridge earthquake, engineers discovered a troubling defect that occurred during construction that caused cracks to form in the welds of the steel frame during earthquakes. If left unrepaired, experts fear, the weakened building could collapse in a subsequent temblor.