OVERVIEW: In October 2015, the City of Los Angeles adopted Ordinance 183893, intended to improve the seismic safety of the City. The ordinance addresses 15,000 buildings in Los Angeles constructed prior to 1978. The ordinance requires analysis of wood-framed, open-front apartment buildings and non-ductile concrete buildings, to show conformance with minimum earthquake standards. Non-conforming buildings must be strengthened or demolished within specified time frames.
IS THIS ORDINANCE NECESSARY? In short, YES!
- The Katrina Hurricane was the worst natural disaster ever to occur in the United States. Property damage and associated loss were estimated to be over $100 Billion dollars.
- A very large earthquake in San Francisco or Los Angeles is estimated by the USGS to result in over $200 Billion in loss.
- The risk to older buildings has been well-recognized for many years. Many previous seismic strengthening programs have been implemented, such as Senate Bill 1953 affecting Acute Care Hospitals throughout California.
- If strengthening of our buildings and infrastructure are not completed, we are vulnerable to a life-changing event that could change the affected region for over 100-years.
IMPACT TO BUILDING OWNERS AND BENEFITS OF RETROFITTING:
While seismic retrofit can be expensive, the costs vary greatly depending on the specific building configuration and detailing, and the experience and expertise of the engineer and contractor. Benefits of Retrofitting include:
- Retrofitting may be economical in the mid-term, with a pay-back period of 5-10 years due to reduced insurance premiums and increased lease rates.
- Once the City determines that a building falls within the scope of the Ordinance, the owner is required to advise current and prospective tenants who use or occupancy the building.
- Strengthened buildings are more attractive, and more valuable, to prospective tenants and buyers and are easier to finance and insure.
- Strengthened buildings are much less likely to suffer damage in any size earthquake, and will therefore be more likely to be green-tagged after an event. This preserves rental income for the owner.
REQUIREMENTS FOR WOOD-FRAME, SOFT OR WEAK-STORY BUILDINGS:
- The City started serving notices to Owners in March, 2016. It will take a year for all owners to be notified.
- The Ordinance affects wood-frame buildings with soft or weak stories, permitted prior to January 1, 1978. The majority of these buildings are multi-family residential buildings with “tuck-under” parking.
- Once notified, owners have two-years to submit plans to the Building Department for strengthening the building or for demolition, unless it can be shown that the existing building complies with minimum earthquake standards.
- From the date of the initial notification, owners have three and a half years to obtain permits for the work.
- Retrofit strengthening (or demolition) must be completed within seven-years of the Notice.
REQUIREMENTS FOR NON-DUCTILE CONCRETE BUILDINGS:
- The City may not serve notices to Owners of Non-Ductile Concrete (NDC) buildings until 2017.
- The Ordinance affects buildings of concrete-frame construction with non-ductile detailing of steel reinforcing bars, permitted prior to January 13, 1977. These buildings are typically of multi-family residential or office occupancy, or parking structures.
- A Structural Checklist must be submitted within three-years after service of the Notice.
- Unless the building is shown to NOT fall within the Ordinance Jurisdiction, owners have ten-years to submit plans to the Building Department for strengthening the building or for demolition.
- Retrofit (or demolition) must be completed within 25-years of the Notice.
OTHER CITIES WILL FOLLOW:
- The City of Los Angeles will not be the last city to pass a mandatory ordinance. Several other cities are in various stages of planning for similar ordinances. Seismic strengthening projects are new to many owners and property managers, and knowledge of the process and potential pitfalls, and teaming with the right engineers and contractors can greatly assist in achieving a positive outcome.
-Courtesy of Lance Kenyon, M.S., S.E. – MHP Structural Engineers