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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

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


Step 6 - Cost Recovery

Cost Recovery

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- T his 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
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