Seismic Retrofit Association
The Seismic Retrofit Association (SRA) was created to inform property owners and property managers about the:
- definition of a seismic retrofit
- benefits gained from a seismic retrofit
- process of acquiring a seismic retrofit
- first steps: finding a qualified engineer
What is a seismic retrofit?
A seismic retrofit is the addition of one or more structural enhancements that will help keep a building, its workers, production equipment and inventory safe from the effects of seismic activity that occurs suddenly or over time. The enhancements might be as simple as straps that secure equipment to complex structural anchors or roofing modifications.
A seismic retrofit can be performed on numerous types of buildings, such as un-reinforced masonry, concrete masonry units, tuck-under parking (also called soft story construction) or frequently constructed concrete tilt-up. For this brief introduction to seismic retrofitting, we focus on a retrofit for a concrete tilt-up building, but if you would like details about seismic retrofitting for other types of buildings, please contact our association.
The most common purpose of a seismic retrofit on a concrete tilt-up building is to keep the roof (or, if applicable, the mezzanine or second floor) from separating from the walls at the building's perimeter. Typically, buildings need reinforcing because the concrete tilt-up walls are very heavy, and when they move during an earthquake, they exert a great deal of force.
A seismic retrofit on this type of building usually consists of adding roof-to-wall anchors and continuity ties, strengthening the key structural connections that have proven to be inadequate in older buildings. Buildings constructed prior to 1985 should be assessed for possible structural deficiencies that may require a seismic retrofit. Buildings constructed prior to 1975 will most likely need a retrofit.
To find out more, see this white paper: What is Seismic Retrofitting? Also, see a step-by-step demonstration of a tilt-up building’s retrofit process, as well as several examples of retrofitting hardware.
Why would a building owner benefit from a seismic retrofit?
A seismic retrofit not only protects the employees, customers, equipment and inventory inside a building, but can lower insurance premiums, attract lenders and help guarantee the building's status as an essential facility, providing peace of mind and longevity for renters.
AThe cost of hardware installed during the seismic retrofit generally becomes equity in the building because it increases the property's value and lowers its Probable Maximum Loss (PML). A PML of less than 20% can reduce insurance premiums. Most building owners can recover their seismic retrofit costs in 2-8 years because of reduced earthquake insurance premiums.
The lower PML a seismic retrofit may provide can also be important when the time comes to sell or add improvements to the building. A PML of less than 20% fulfills the requirements of most lenders and because more lenders will be able to lend on your property, you'll attract more qualified buyers or be able to more easily acquire cash for improvements.
Perhaps the most practical benefit from a seismic retrofit is very simply, the prevention of loss. The losses incurred from a fifteen-second earthquake can be devastating both to the building as well as the people inside it. Many organizations have found it necessary to cease operations temporarily or permanently because of the destruction caused by seismic activity. Lost profit because of an earthquake is often related to:
- Loss of life
- Medical costs
- Loss of tenants
- Litigation from employees & tenants
- Cost of temporary relocation
- Loss of assets within the building
- Loss of building productivity, building use and overall business operations.
A seismic retrofit will eliminate or minimize these losses, ultimately benefiting the building's owner.
What is the process for acquiring a retrofit?
A building owner will contact a qualified structural engineer to inspect the building and draft plans for a seismic retrofit. A qualified engineer is one who has successfully completed at least 3-10 seismic retrofit projects. All of the engineering members of the Seismic Retrofit Association are considered qualified engineers.
- A structural engineer will draft the plans.
- The plans must be approved by the appropriate city.
- A commercial seismic retrofit company will be selected to create a detailed proposal for work to be completed.
- The proposal is signed and the contractor begins work, after obtaining the proper permits.
- After the work is completed, the engineer will perform a site visit called a Final Observation Report to ensure the work has been completed correctly. If this is the case, the project is almost complete.
- If work was incorrectly performed or new issues arise, the contractor will need to take corrective action. The engineer will then perform another site visit to sign off the project. Because additional work or inspection can be costly, building owners should hire contactors with experience in seismic retrofitting who can get the job done correctly the first time and with a proven record of productive communication with engineers and inspectors.
- After the structural engineer submits the Final Observation Report, the contractor schedules the final inspection with the city, and the permit card is signed-off by the city, indicating that the project was completed per plan.
How Would a Building Owner Take the First Step?
Since contacting a qualified structural engineer is the first step in performing a seismic retrofit, it is important for a building owner or property manager to make a wise choice when choosing an experienced structural engineer.
The Seismic Retrofit Association knows that while many engineers claim that they can draw seismic retrofit plans, only a select few are sufficiently knowledgeable and experienced in this area. Quite frequently, the "cheapest" bid from an engineers ends up being the most expensive because engineers who lack experience in seismic retrofits often overbuild plans, costing their clients considerably more in retrofit costs. Find out what happened when one building owner chose the cheapest bid.
SRA seeks to help property owners and managers connect with highly qualified structural engineers. Building owners and property managers who work with SRA members find that they save time and money. See the list of SRA engineers here.
The Seismic Retrofit Association's membership program is open exclusively to licensed structural engineers with extensive experience in commercial seismic retrofits. Learn a ton more.