California Isn’t Turkey, but We’re Still Vulnerable

Media reports on Tuesday’s 7.4 earthquake in Turkey had their usual tie-ins to the seismic hazard in California, many of which emphasized how much better Los Angeles would do in a similar earthquake. But while this is true in the area of life loss and injury, property loss is another story. All too frequently, owners will not improve existing buildings and developers will resist better earthquake designs for new buildings.

In my line of work, I have reviewed hundreds of buildings and dealt with as many property owners, commercial mortgage brokers, institutional investors and building owners. Many of L.A.’s existing buildings would be considered deficient--sometimes grossly so--in terms of earthquake performance. These include mid- to high-rise office buildings, hotels, industrial buildings and certain types of multifamily apartment complexes.

Unfortunately, improvements to reduce seismic vulnerability are rarely done on a voluntary basis, although a lender or investor sometimes will force the issue. Part of the reason for the reluctance to bring buildings up to snuff is that the cost of upgrading may not be cost-effective, e.g., owners believe that low rents or high vacancies in an office building do not justify the large expense of upgrading.

Some are lulled into believing that because a building has survived other earthquakes, it will survive future ones. But past performance is not necessarily a good indicator of future performance. A Sherman Oaks high-rise sustained minor damage in the 1971 San Fernando earthquake. A 1986 review found the building would sustain significant damage in any future strong ground-shaking. That is what happened in the 1994 Northridge earthquake. Had the shaking gone on longer, it might have collapsed.

As for newer buildings, it is true that building codes have improved, but the emphasis has been on life safety, not property protection. The most recent Uniform Building Code greatly improves on earlier codes, particularly for sites located near faults and/or for certain types of buildings. But, again, life safety is the primary concern and the cost of making buildings safer in earthquakes is an issue. Regarding the latter, my firm recently reviewed a proposed project in which the developer was pushing engineers to submit plans to the building department before the newest Uniform Building Code took effect, although the cost of improved seismic performance would have been modest in terms of the overall project cost.

Everyone seemed aware of earthquake safety issues immediately after the Northridge quake. Now, memories have faded. But this is no time for us to relax about the safety of our structures. The degree of destruction that happened in Turkey won’t happen here, but the potential for severe structural damage exists.