Should you be considering a seismic retrofit in Los Angeles?
Seismic retrofitting involves strengthening a structure to make it more resistant to earthquake shaking and damage. In many cases, the retrofitting process itself strengthens an older home by bolting the house to its foundation with anchor bolts, or with bracing and bolting. There are more than one million of these types of vulnerable older homes in high hazard earthquake areas across California, and many of those homes are in and around the city of Los Angeles. Many of these older homes were built before modern building codes were in place.
This house sustained severe damage during the Southern California Northridge earthquake in 1994. The damage was so extensive that it was “red-tagged,” which means the structure is too dangerous to inhabit. Photo credit: FEMA
A recent study by the Pacific Earthquake Engineering Research (PEER) Center estimates that the owners of retrofitted houses can save between $10,000 and $200,000 in repair costs resulting from a major earthquake by house bolting or bracing and bolting their homes with a seismic retrofit.
This research helps to demonstrate that seismic retrofits work, and that earthquake retrofitting is worth it when you compare the potential cost of repairing a damaged home. Research and analysis suggest that spending a smaller amount of money to help reduce damage and help make your house more earthquake-resistant may be more beneficial than facing a much larger repair bill after an earthquake.
What are the benefits of getting a home (or residential) retrofit in LA?
Strengthening your house with a seismic retrofit in Los Angeles is a good way to lessen the potential for costly earthquake damage, saving you what could be tens to hundreds of thousands of dollars in repair costs. It can help provide peace of mind, knowing that you have helped your family better withstand an earthquake by strengthening where you live.
These two side by side houses, shown after the magnitude 6.0 2014 American Canyon (South Napa) earthquake, illustrate the benefit of a seismic retrofit—as one had been strengthened and one had not.
How much does an earthquake retrofit cost in Los Angeles?
Earthquake retrofit costs in Los Angeles can vary, to retrofit a home on a raised foundation usually costs between $3,000 and $7,000. But a skilled Do-It-Yourself homeowner can save thousands of dollars by doing the work themselves.
Older houses with steps up to the first floor are on a raised foundation. This means they have an area underneath the first floor, which is referred to as a crawl space. These types of houses can shift off their foundations from shaking. They often can be strengthened by bolting the house to its foundation.
Larger homes, those built on hillsides and those with basements and rooms over garages will typically cost more to retrofit.
Importantly, homeowners can remain inside their dwelling as, in most cases, workers are able to do the retrofitting work without entering the residence. Compared to the potential cost of repairing an earthquake damaged home, spending a smaller amount of money to help prevent damage can help avoid a much bigger repair bill after an earthquake.
Does Los Angeles offer any retrofit grant programs?
You might be wondering, is there is a Los Angeles earthquake retrofit program? There is a grant program available to eligible Los Angeles area residents to help with the costs of a seismic retrofit in Los Angeles. The California Residential Mitigation Program (CRMP) Earthquake Brace + Bolt (EBB) program offers grants to eligible Californians in higher-risk ZIP Codes.
Earthquake Brace + Bolt (EBB)
The Earthquake Brace + Bolt program is an incentive program that offers seismic retrofit grants of up to $3,000 to qualified homeowners with eligible houses in a select number of higher-earthquake-risk ZIP Codes.
ZIP Codes chosen for EBB program participation follow these two criteria:
- Earthquake Hazard: Hazard was identified using the United States Geological Survey (USGS) earthquake hazard map for California.
- Earthquake Vulnerability: Vulnerability was represented by identifying the percentage of pre-1940 houses in ZIP Codes in California (U.S. Census Data). Older houses are more likely to require earthquake bracing and bolting.
EBB may include other ZIP Codes in a city to allow for efficiency for contractors and building departments, thereby making more homeowners eligible for a grant.
Over time, EBB hopes to include more high hazard areas in California with additional funding from a variety of sources.
You may be eligible for an EBB grant if your house:
- Is owner-occupied and is in one of the EBB ZIP Codes.
- Is built before 1980 (but qualifying houses are more prevalent before 1940).
- Has a raised continuous perimeter concrete foundation.
- Sits on level ground or a low slope.
- Is of wood-framed construction.
If your household income is less than $72,080 per year, you may also be eligible for EBB’s supplementary grant, which covers the full cost of a retrofit. Sign up on the Earthquake Brace + Bolt website to be notified when registration opens for this grant.
Seismic retrofit work cost recovery program
Strengthening your home to make it more resistant against earthquake damage and loss is important. In addition to the program described above, there are a number of other potential funding sources available.
Learn about other types of financial assistance to help you retrofit your home to make it stronger against earthquake damage.
How to get a seismic retrofit in the city of Los Angeles
When it comes to Los Angeles retrofit requirements, once you have identified your house type and its vulnerabilities and you determine the type of retrofit that is needed, it is time for you to make a plan to carry out the retrofit. This includes hiring a contractor (or considering doing the work yourself), deciding how you will pay for the retrofit, and scheduling out the timeline for completion.
Earthquake retrofit contractors in Los Angeles
It’s always best to get bids from several contractors before you make your final selection. The California State License Board (CSLB) also recommends obtaining more than one bid.
You also can check out EBB’s list of contractors, who have received training and are experienced on how to do a brace and bolt retrofit.
Keep in mind that if your home requires an engineered retrofit, you or your contractor will need to hire a licensed structural or civil engineer to advise on your retrofit efforts. EBB has a Licensed Design Professional Directory to help you with your search.
What are the structural risks of each type of foundation?
Los Angeles is known for its cultural diversity and the same holds true for the way its homes are built. Because of the city’s housing diversity, these different types of homes pose their own risks and may require their own type of retrofitting to strengthen their ability to withstand the devastating force of a major earthquake.
Raised Foundation
A house with a raised foundation has an area underneath the ground floor (first floor), which is referred to as a crawl space. Industry professionals use the term “cripple wall” to define crawl space walls. These older homes with steps up to the first floor can shift off their foundations from shaking. They can be strengthened by bolting or bracing and bolting the house to its foundation.
Above is an example of a house with this type of foundation—you can find more information on this risk at the Raised Foundation House Retrofit page.
Post and Pier House
A post and pier house is a type of raised foundation home, in that there is an area created underneath the dwelling floor.
Find more information on this risk and what you can do to minimize it at the Post & Pier House Retrofit page.
Hillside House
These houses have certain, inherent structural elements that can make them vulnerable when earthquakes occur. They are built on hillsides or sleep slopes and often are set on tall, narrow posts or columns, with or without diagonal bracing.
Hillside houses can be at risk when it comes to strong shaking and may need to be strengthened by being properly retrofitted to withstand earthquakes.
You can find more information on this risk at the Hillside House Retrofit page.
Houses with a Living Space Over a Garage
Houses with one or more floors of living space over an attached garage can be especially vulnerable to shaking. Their vulnerability to earthquakes comes from a living space being atop the garage beneath, which lacks structural soundness. These are sometimes referred to as “soft story buildings.” The garage area of these homes also may have walls and doors that are not braced to resist earthquake motion. Retrofitting the garage space (soft story retrofitting) can make these homes more resistant to earthquake damage.
Above is an example of a house with this type of foundation—you can find more information on this risk at the Living Space Over Garage House Retrofit page.
What is the earthquake risk in Los Angeles?
In their most recent report, the United States Geological Survey (USGS) predicted a 93 percent chance 6.7 or greater earthquakes striking Southern California, based on a 30-year period, beginning in 2014.
The San Andreas Fault in Los Angeles
When most people living in Southern California and, specifically, the Greater Los Angeles area, think about earthquake risk, they think of the region’s proximity to the southern portion of the San Andreas fault. The San Andreas is California’s longest fault and gets the most attention. It slices through the Los Angeles area along the north side of the San Gabriel Mountains. It can cause powerful earthquakes—as big as magnitude 8.0.
Retrofitting lessons learned from the 1994 Northridge Earthquake
While the San Andreas is the Los Angeles area’s most notorious fault, earthquakes in the region also happen on other, smaller faults.
Many remember the magnitude 6.7 earthquake that struck near Northridge in the San Fernando Valley in 1994, killing 58 people, injuring more than 9,000 and causing more than $49 billion in economic loss. This was caused primarily by the Northridge Thrust fault, which triggered activity in several other faults.
Many of the residential structures that sustained severe damage from the Northridge quake occurred because of their inherent vulnerabilities, such as unreinforced chimneys, houses not being braced and bolted to their foundations, and soft story (garage) structures.
Here is an example of a house with chimney damage following shaking during the Northridge earthquake.
How to protect your home
Even though it is impossible to accurately predict when an earthquake will occur, you can still take measures to reduce damage and improve the chances of staying safe by preparing in advance for earthquakes. The ways in which you can protect your home and your family in the event of a major earthquake (in addition to finding out if your home needs a seismic retrofit in Los Angeles) include:
- Create an earthquake safety plan for you and loved ones, including pets.
- Know your risk for earthquakes in your area and what you must do to stay safe.
- Make or purchase earthquake safety kits.
- Identify and fix potential earthquake hazards in your home.
- Secure fixtures, furniture, appliances and other items inside your home.
- Visit the Seven Essential Earthquake Safety Steps page for more safety, protection and emergency preparedness tips.
Determine your structural risks
If you live in the Los Angeles area and your raised foundation older house was built before 1980, earthquake experts say your dwelling is especially vulnerable to damage from earthquake shaking because it was built before seismic building codes were put in place. According to U.S. Census data, 74.8 percent of the housing units in Los Angeles County fall into that category of being built before 1980 and could be in need of an earthquake retrofit in Los Angeles. The frames of hundreds of thousands of these type homes are not bolted to their foundation. And without adequate bracing and bolting, these houses can slide or topple off their foundation during an earthquake.
While raised foundation older homes are prevalent in Los Angeles, there are homes in the City of Angels with other foundation types that may be in need of retrofitting. Those homes include “post and pier” houses, hillside houses and houses with living spaces over garages. You can learn more about these homes, their foundations and how to determine whether they need to be retrofitted at our Strengthen Your House page.
Consider a seismic retrofit
As discussed in previous blogs, strengthening your house with a seismic retrofit in Los Angeles is a good way to help prevent costly earthquake damage. It can help provide peace of mind, knowing that you have helped your home and your family better withstand an earthquake.
The retrofitting process itself can be straightforward and often not as intrusive as homeowners might think. Depending on the type of retrofit needed, the work usually can be done in a few days and homeowners can remain inside their dwelling, as in almost all cases workers do the retrofitting without entering the residence. The older your house, the greater the odds it may need to be seismically retrofitted to have a better chance to withstand earthquake damage. For more information on the importance of retrofitting different home types, visit our Strengthen Your House page.
Strengthen your home
For many Los Angeles area homeowners, the value of their property and the equity they have in it represent the lion’s share of their savings and retirement nest egg. An earthquake retrofit in Los Angeles can significantly reduce the chances of an older home falling or sliding completely off its foundation—perhaps resulting in a total loss, even in a moderate earthquake.
The primary goals of retrofitting are to:
- Allow you and your family to shelter in place.
- Protect against catastrophic financial loss.
- Help you and your family survive when a major earthquake occurs.
Living in Los Angeles, it is not a matter of if, but when a major earthquake will occur. You can better protect and prepare yourself and your family before the next big one strikes by investing in an earthquake retrofit. Provide that protection by taking the path of most resilience by strengthening your home against earthquake damage today. For more information on the importance of retrofitting older homes, visit our Strengthen Your House page.