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Soft Story Seismic Retrofitting

What is Soft Story Retrofitting?

To Retrofit is to add an element to something that it didn't have when it was manufactured.  Soft Story Retrofitting focuses on tuck-under parking buildings or buildings which may have less windows on the top of a building, making it stiffer on top, and a higher risk for collapse.

Buildings built before 1978 are targeted, since that is when the building code changed for lateral movement.


Zebra Construction measures all sides of your building and does a stiffness check on all sides before sending a proposal, avoiding surprises from engineering to construction phase.

Process with Zebra Construction Inc.

Step 1 - The Proposal

The first step would be to have us out to visit your property.  We would love to meet you there and teach you about retrofitting and answer any questions you may have!  Once we have measured, we will get together with one of the 3 engineers we work with and confirm design ideas from measurements.  We then send you a proposal with engineering and estimated construction based on design and projects similar to yours we have completed in the past.

Do you Already Have Engineering Plans?

Stiffness Check

A stiffness check is when we measure the building to decide if it falls under the city guidelines of it being soft. If it is soft it needs retrofitting.  We do this to all sides of your building before sending a proposal to be sure it is accurate.



Not Soft

Not Soft


The Proposal

Step 2 - Creating The Plans

Engineering Plans

The Engineer Listed on your proposal/contract is who will be completing the plans. We have seen plenty of over designed plans, which are not economical to build, and we do not want this to happen to you, or anyone. 

DRAFTING - The first step is sending a drafter to your property to measure and then draw the building to scale.

DESIGN - The engineer then takes the As-Built drawing the drafter created and begins his/her calculations. 

SITE VISIT- The engineer will then visit the site with someone from the contracting team to discuss their ideas and make sure nothing was missed on the As-Built Drawing, like sewer lines/ gas lines etc.

DRAFTING- Once the design is decided, it is drafted and printed ready for submittal.

SUBMITTAL- We submit the plan to the city on your behalf. Plan Check is an extra fee which must be paid to the City. It ranges from $500-$2800 +/- depending on expediting status and municipality.

CITY PLAN CHECK- Once plans are submitted to Plan Check (The City), we wait for their response when they are ready. We will provide the city's link if available for your project so you may view updates.

CORRECTIONS- Once the plans have been reviewed by a supervisor, they will be picked up and if any corrections were given, they will be addressed. Corrections are usually just clarifications, and very minor. Corrections will be addressed and a request for a meeting with the plan checker will be made. 

PLAN CHECK MEETING- The engineer will then meet with the plan checker to review the corrections to be sure they have everything necessary, and then give Ready To Issue Status (RTI), which means approved plans!

Step 3 - Fixed Construction Price

If you have plans, we can give you a price to construct if you can send a PDF to

Once we have created plans, we will give you a fixed construction price which will not change unless there is termite damage repair, lead/asbestos abatement or extra work not on original plan. Any changes will be charged to you at Zebra Construction's Cost. 

Fixed Construction Price
Housing Clearance

Step 4 - Housing Clearance

Zebra Construction will submit Tenant Habitability Plan or Means & Methods Plan & Post/Mail to tenants on your behalf. The Tenant Habitability Plan is a plan which tells tenants construction is happening. It includes city forms which tell tenants about their rights etc. Here is a link to the city's website and forms we are required to notice tenants. We include our own letter summarizing the packet which is helpful in negating questions from tenants and directs them to us for any questions. Means & Methods Plan will be sent to tenants via Certified Mail.

  • Tenant Information is required

  • Once THP (Tenant Habitability Plan) is submitted, and approved, we must post within 5 days.

  • After THP is posted, we must wait 15 days for any tenant appeals

  • If there is a tenant appeal, a hearing notice will be sent to the owner

  • Zebra will attend tenant hearing with/for you if necessary

  • Once Appeal Period is Passed, or Hearing Response is received we will get permit

  • We post a reminder notice to tenants 48 hours before start date of construction

Step 5 - Construction


Step 6 - Cost Recovery

Cost Recovery

Zebra Construction Adheres to all OSHA guidelines & Local Laws. They will provide proper signage to reduce liability as much as possible.


Demolition Phase -  Zebra Removes all Debris from the site daily.

  • Stucco Tear Back for Drag Systems & Shear Walls

  • Saw Cutting

  • Excavation (Trenches will be covered to allow tenant parking in the evening)

Pre-Construction Meeting

  • City Inspection/Meeting with the project's Engineer, Contractor, City Inspector & Property Owner/Manager

  • This inspection is after all demolition is complete, so that we can see if there are any changes necessary on plan and if there is termite damage, the extent can be decided. We recommend treating lumber for termites while exposed.

Structural Steel & Rebar Installation

  • Steel & Drag Systems will be Welded with Deputy Inspector Present

  • Clips/Framing completed

  • Rebar Tied Deputy Inspector to Check Rebar

  • Epoxy Dowels Installed with Deputy Inspector Present

  • Structural Observations for Steel & Groundwork

City Inspection for Steel & Groundwork

  • City Inspector's Approval will grant permission to Pour Concrete

Pour Concrete

  • Deputy Inspector Present to Check Mix

Lath Installation

  • Installation of Lath for Stucco

City Inspection for Lath

  • Carbon Monoxide & Smoke Detector Declaration Required by Owner

  • Seismic Shut Off Valves must be Installed, Permitted & Permit Finaled

Stucco Installation

  • Scratch Coat, Brown Coat, Color Coat

Paint to Match

  • Painting will be completed 2 weeks after stucco, to allow it to cure

Final City Inspection

  • OK for C of C (Certificate of Compliance) given

In Los Angeles, you are able to recover up to 50% of the costs of the retrofit through rent increase over 10 years with the maximum rent raise of $38/month per unit.  Once Project is completed, Zebra Construction will submit Cost Recovery on your behalf. Once it has been approved, the city will send your tenants and you a letter on amounts to raise rents for tenants. We will need "proof of payment" in the form of cancelled checks from your bank to submit to the city and we provide the rest.

Other Things You Need to Know!


Lead & Asbestos

Buildings were built before 1978 could have materials containing Asbestos & Lead. Click here for more information about lead & asbestos.  Before Tenant Habitability Plan is submitted, Lead & Asbestos testing must be done in the work area. We complete the testing with AIH Labs & results must be kept on the site per OSHA standards through out the job site. If the testing comes back with high enough levels of Asbestos to require Abatement, it is the owner's responsibility to Abate before construction begins. We recommend using Harbro Environmental for Abatement, but property owners may collect their own bids for this service if Necessary.

Deputy Inspections

There will be several Deputy Inspections required throughout your project. By Law these must be hired and paid by the owner. A deputy inspector is a 3rd party inspector, who does not work for the city or the contractor to be sure all plans and specifications are being followed. 

You can also use a company which dispatches deputy inspectors. Mesa Inspections, Abrahams Inspections, & John Lorenzo Deputy Inspections could assist you with this. The UT Inspector you can use is Fransen Inspection Technology.


For a typical retrofitting project, you will need a deputy inspector for the following processes. They will give a report to the contractor which must be provided to the city inspector at each inspection.


  • Epoxy Dowelling - The Deputy Inspector will check to be sure no dust is left in the hole drilled, and that the proper amount of time has passed before inserting dowels.

  • Rebar- The Deputy Inspector will check counts, sizes, and placement of rebars per plan.

  • Dry Pack/High Strength Grout- If your project is completed without a Monolithic Pour of Concrete for pads and grade beam or tie beam, this would be under the column of your moment frame columns or cantilever column.

  • Field Welding- For any on-site welding, there must be a Deputy Inspector present. 

  • High Strength Concrete- Any Concrete over 2500 PSI will need to have a deputy inspector present to take samples to check the strength and mix of the concrete. This is all Retrofit Projects having concrete poured, as it will most likely be 3000 PSI Concrete.

  • Wood Shear- You will need a deputy present to check the framing and also be present while you are putting up the plywood on any shear wall or sheathing to check the nailing patterns.

  • High Strength Bolting- A deputy inspector must check any high strength bolting on a project.

  • Ultrasonic Testing- This is non-destructive testing done on the welding of the steel to be sure they are the proper strength.


Structural Observations

Structural Observations are required to be completed by the Engineer of Record. They will visit the site before a city inspection and leave a report with the contractor to be turned into the city inspector. The following are reports necessary. These reports must be paid to the engineer directly by the owner. The typical cost is $350/inspection.

  • Pads/Footings

  • Structural Steel/Moment Frame

  • Wood Frame/ Shear-Wall

  • Final

  • Existing Structural Element Integrity

  • Engineer's Certificate of Completion

Seismic Shut Off Valves

Seismic Shut Off Valves must be installed on each gas meter. This is per ordinance 174478 per Los Angeles Municipal Code.  The Retrofit Permit cannot be finale until all valves are permitted, installed, and permit is finaled. Any licensed plumber will charge $350 +/- for valve, permit and installation of a 3/4" valve which is the most common.  Any thing that seems like it may be too good to be true, may be. Be sure you use a licensed plumber and that the permit is pulled and has been finaled.  If your project needs shut off valves and you have not completed by the time the stucco is started, we will have our plumber install and charge $350 per 3/4" valve, $400 per 1" valve, $425 per 1 1/2" Valve, and $450 for 2" valves.

Moment Frame

Moment Frame

Welded Steel Frame. Consists, of two columns & beam. Usually attached to the building by welding to drag plate, nailer plate or existing beam.

Moment Frame
Moment Frame
Moment Frame

Cantilever Column

Cantilever Column

Wide Flange Column or HSS column. This column can also be a "built up" which has another piece of steel welded on each side, so that it can work in two directions, and save the need for 2 columns.

Cantilever Column
Cantilever Column
Cantilever Column

Grade Beam or Tie Beam

Grade Beam

Grade Beam is a Rebar & Concrete Beam in the ground below slab which sits on top of the pad footings for the columns. This keeps the column(s) from tilting and also from sliding. A tie beam does the same, but is only for sliding.

Grade Beam
Grade Beam or Tie Beam



Sheathing is blocking and structural plywood added to the ceiling of a structure to stiffen.


Shear Wall

Shear Wall

A Shear Wall is a wall with added blocking and structural plywood added to cause extra stiffness and strength.

Shear Wall
Shear Wall
Shear Wall

Drag System

Drag System

A drag system can be a steel plate over wood members or making the existing beam continuous by welding connections, putting blocking between joists with clips or adding extra stud bolts in beam.

Drag System
Drag System
Drag System

Frequently Asked Questions

  • What is soft story retrofitting?
    A soft-story retrofit simply adds to and reinforces the structure of the building so it can hold up much better in an earthquake. The main goal is to make sure the building is still standing after an earthquake hits and ensure the safety of everyone in and around the building. Soft-story buildings are particularly susceptible to earthquake damage because of large, unreinforced openings on their ground floors and in their typically wood-frame construction. These openings often accommodate parking spaces, large windows and expansive lobbies in residential and retail buildings. Without proper design, such structures are much less able to withstand the lateral forces -- forces that push a structure side to side -- that earthquakes generate. Once the first floor folds, the upper floors pancake down on top of it, crushing anything underneath
  • Who needs soft stoty retrofitting done?
    If the property has "tuck-in" parking and has two or three stories, and has more than 3 units, it may need some retrofitting done. If you received a letter about your deadline approaching to have your permit pulled, you may need retrofitting done. if you live in any of the following cities and own an apartment building, you may need retrofitting done: Los Angeles, Santa Monica, West Hollywood, Pasadena, Beverly Hills. We only retrofit for commercial properties*
  • Which cities have soft story ordinances?
    Los Angeles Santa Monica Beverly Hills West Hollywood Pasadena Voluntary: Long Beach, Burbank.
  • For what reasons would I redesign my soft story retrofit plans?
    Redesigning plans for your project can make sense for several reasons: Cost There are many different engineering solutions to meet the standards of compliance with city ordinances. Some designs can be much more costly to construct than others. Zebra works with several design professionals who specialize in reducing the scope of work for each project and often times can save you money on the full scope of the project. ​ Error Often times engineers send inexperienced drafters to draw your building. Many times they don’t notice utilities, existing structural elements, or unique facia that may be costly to deal with in the construction phase. Zebra always makes sure that each possible construction issue Is avoided before the plans are submitted to the city. ​ Efficiency Simply put. Some plans are more involved and time consuming to build. Redesigning can often times lessen the impact on the tenants. We make sure the new plans will keep the construction phase to a minimum in both time and tenant disruptions. Tenants almost always will have overnight parking available and a clean and safe place to live. Peace of mind How has your experience been with the engineer you hired? Have you had issues with communication, timeliness, or unforeseen charges? The engineer is still involved throughout construction. They attend site visits for structural observations and must be available for potential design changes if the existing conditions don’t match the approved plans. If the engineer does not communicate or show up for site visits, it can lead to problems. Zebra always offers transparent and fixed proposals on soft story projects, we promise no change orders or unexpected charges.
  • What is the most important thing to consider when starting a project?
    The most important part of a soft story retrofit project is the engineering as it ultimately determines the construction costs. There are multiple ways to design a soft story retrofit project and the city will not tell you if there are extra elements which may not be needed for an economical build. There are a few different options when it comes to engineering. Option #1: Design/Build company which can create your plans and do the construction. Questions to ask: Are construction costs fixed up front? What types of changes or extra charges do they forsee? ​ Option #2: Hire an Engineer or architect. Questions to ask: Who are contractors you have worked with on retrofit projects? (Call them!) What are some projects you have completed? (Can you talk to the contractors and owners?) What extra fees are there? Structural observations? Field changes? Can you receive the plan copy before it is submitted? This way you can get the opinion of a few contractors on the design to see any issues which may arise during construction before you are locked into the design. ​ Pros and Cons: If the engineer is also the contractor, they may not design it the most economically to profit from construction. If you work with a contractor who fixes their construction estimate before plans are created, you know they will keep the engineer on budget since they have a set amount. ​ If the engineer is working solo, they may not know the exact cost of construction items. For example, a shear wall may seem like an economical option to most engineers. But they are not taking into consideration the old plaster on the opposite side of the wall in the tenant's unit which could crack and crumble due to age while knocking stucco down on the opposite side. They also may not take into account the extra labor and time it takes to frame a shear wall and also stucco it at the end of the project. A steel solution is more economical most times and projects move much quicker with steel. ​ No one can tell you what the best option is for you, but these are some things to think about when making your decision. ​
  • What is a THP?
    What is a Tenant Habitability Plan (“THP”)A Tenant Habitability Plan, commonly known as “THP,” is the heart of the Tenant Habitability Program. THP is a document prepared by a property owner with the assistance of the Department’s Tenant Habitability Program unit staff. The THP describes the scope of the work and the methods that the owner, contractor, and workers will use to mitigate potential impact to the tenants and the tenants’ personal property during the period that renovation work occurs in a tenant’s unit or the subject building and premises. The intent of the Tenant Habitability Program is to protect tenants from untenantable housing conditions and/or forced permanent displacement. If you plan to renovate, repair, or alter a building subject to the Rent Stabilization Ordinance (RSO), your proposed work may qualify within the scope of the Tenant Habitability Program. There are two types of qualified work for the Tenant Habitability Program Primary Renovation Program Landlords wanting to take advantage of the Primary Renovation Cost Recovery program must first complete the requirements for the Tenant Habitability Program. Once the work has been completed, an application can be prepared for a Primary Renovation project. Seismic Retrofit City Council passed the Earthquake Hazard Reduction Ordinance to establish mandatory standards for earthquake hazard reduction in wood-frame buildings with soft, weak, or open-front walls and existing non-ductile concrete buildings.
  • How much does retrofitting cost?
    Through the Community Action Plan for Seismic Safety (CAPSS) analysis, it is believed that these retrofits will cost between $60,000 and $130,000, depending on the building size. Book an inspection with us and get an accurate estimte. 310-890-3989
  • How long does retrofitting take?
    ~ 4 to 12 weeks On average a project can last from 4 to 12 weeks, after receiving a client's permits and plans, depending on the scope of work.
  • What is a soft-story wood-frame building?
    A soft or weak story floor, wood-frame building is a structure where the first story is substantially weaker and more flexible than the stories above due to lack of walls or frames at the first floor. Typically, these buildings contain large open areas for parking or commercial space such as restaurants or convenience stores on the first floor leaving the building highly vulnerable to damage in an earthquake.
  • What are the benefits of performing a seismic upgrade?
    Performing a seismic upgrade of a soft story building will reduce the risk of collapse during an earthquake. This will prevent more people and businesses from being displaced.

Follow Michelle Durey as she gives us a tour of this soft story retrofit project in North Hollywood and shows us how Zebra Construction was able to reduce the scope of work by submitting a new engineering plan!


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