This is part two of a series of articles on Soft-Story Retrofit in Los Angeles focusing on economical solutions for seismic retrofit. In part one, we discussed Seismic Hazard in Los Angeles area. Here, we address several common questions by property owners and shed light on the economical ways for seismic retrofit of your property.
It is known that buildings with tuck under parking areas or those that second floor cantilevers out more than a specific length, are vulnerable to earthquake damage. The reason is that such buildings are practically sitting on top of steel posts that cannot take the horizontal earthquake load. The consequences of a strong ground motion are obvious from the Northridge earthquake back in 1994 – (see above photo).
The fact that some buildings did not sustain damage during 1994 earthquake, does not guarantee that those buildings are safe from future earthquakes. The interplay of future earthquake’s magnitude (indicating the released seismic energy), proximity of future earthquake’s epicenter to the building, deterioration level of the building at the time of future earthquake, and the location of building can lead to a catastrophic scenario.
Through frequently asked questions we explore economical retrofit methods and corresponding procedure.
Is There a Need For Tenant Relocation?
The experience of engineer pertinent to soft-story design and type of the retrofit method are important factors determining whether a tenant needs to be relocated or not. An experienced engineer is able to provide a retrofit solution that can be constructed from the parking area without a need to access inside the units with no tenant relocation.
What Are Important Retrofit Deadlines, Timelines?
The city has sent series of letters to soft-story property owners, notifying them of the issue, and also ordering them to retrofit the property. The “Order to Comply” letters are scheduled based on the property size. After receiving the “Order to Comply”, the clock starts ticking and three deadlines will be approaching which property owners should be fulfilling in three major steps : (1) Prepare a retrofit plan, (2) start retrofit construction, (3) finish the retrofit construction and obtain a “Certificate of Compliance” from the City.
Soft-Story retrofit has the following deadlines for major phases of the retrofit process. When you receive your permit for the construction, the permit is valid for six months after the time the permit was issued. The permit can be extended another six months by submitting a request to the City of Los Angeles – who issues the permit. Such extension is possible up to 3.5 years from the time of receipt of order to comply.
Deadlines for Taking Action Regarding Retrofit:
|Deadlines from the receipt of the order to comply letter|
|2 years: Submit proof of previous retrofit, or plans to retrofit or demolish|
|3.5 years: Obtain permit to start construction or demolition|
|7 years: Complete construction|
What are the Different Retrofit Methods?
There are various methods to retrofit a wood-frame building. These methods include 1) shear-walls, 2) cantilever columns and 3) moment frames. Each of these techniques has their own specifications. The difference between shear-walls, cantilever columns, and moment frames are provided below. The figures show the overall geometry of each retrofit method. The following table shows the comparison between the different systems of retrofit.
Estimated retrofit cost without having engineering plans can vary a lot among different companies depending on the method of contract fulfillment, experience of the engineering and efficiency of the contractor.
The selection of retrofit method depends on various items including the geometry of the buildings, location of walls and direction of existing beams, number of stories on top of the parking area, the depth of the tuck under parking area, and material of the building elements (wood or steel beams/columns/posts). This is the reason that LA RETROFIT provides a free inspection to be able to investigate the most appropriate solution for soft-story properties.
Different Types of Soft-Story Retrofit Methods and Their Relative Cost
There are two general methods among Soft-Story retrofit companies
- The first method is separating the engineering design and construction into two individual contracts (similar to city’s break-down of the process).
- The second method is doing the engineering and construction under one single contract (design-build). The first method which engineering and construction are contracted separately are preferred among many as it gives property owner the freedom to get accurate construction bids after engineering plans being approved by the City. The second method that contracts engineering and construction in one contract appeals to certain group of property owners who don’t mind paying an extra cost that retrofitting companies add to the overall cost because of uncertainties involved in the non-existence of engineering plans at the time of their bid.
How Important is the Engineering Phase?
Engineering aspects of the retrofit work certainly plays a major role in the overall cost of the project. Often, it is the case that methods of retrofit for a project are exchangeable. It is the duty of an engineer to not only make sure of the safety of his design, but also to balance safety and economy of the project. An experienced engineer who is equipped with sophisticated engineering tools is able not only to model the existing capacity of the building and design only for the short-comings, but also to try different retrofit methods in a reasonable amount of time and choose the most economical one.
What Are the Minimum Requirements to Get the Soft-Story Retrofit Compliance?
- Engineering plans prepared by licensed engineer and approved by the City of Los Angeles
- Architectural Clearance
- Structural Clearance
- Fire Clearance
- Historic Preservation Clearance
- Tenant Habitability Plan (THP)
- Permit Pull and Construction
- Inspection by City inspector at critical steps
- Final Inspection
- Certificate of Compliance
What is THP?
THP stands for Tenant Habitability Plan and serves at a balance sheet that City of Los Angeles will use to assess the rental income against the retrofit cost in order to justify the rent increase per unit per month. The THP package is a series of forms and notifications that a property owner is in charge of putting correct information in, to notify the City of Los Angeles regarding expenses and income. Notifications are directed to the tenants to let them know of the retrofit construction process and any potential limited access to parking area, etc. during the construction phase and should be served to the tenants at least 60 days prior to the construction.
Dr. David Hosseini has a PhD. in Structural Engineering and Seismology the founder and president of LA Retrofit. LA Retrofit is an engineering and construction (design-build) company providing soft-story retrofit services. LA Retrofit implements state of the art technology and proven research to guarantee a retrofit solution that balances safety and economy. LA Retrofit team is comprised of highly experienced engineers and skilled crew members guaranteeing a hassle-free, economic, and efficient retrofit process. For more information, call (213) 713-3058, email [email protected] or visit www.la-retrofit.com.