Soft-Story Seismic Retrofit – City of Culver

1. Screening report, due one year after Notice to Comply

A licensed Civil or Structural Engineer performs a structural evaluation and prepares a Screening Report to determine whether the building is exempt or requires a seismic retrofit.

The screening typically covers:

• Review of the building’s configuration and wall lines
• Identification of SWOF conditions
• Preliminary assessment of load paths and diaphragms
• Review of foundations where accessible

If the building is documented as exempt, no retrofit is required under the ordinance.

2. Retrofit plans, due two years after Notice to Comply

If the screening shows a retrofit is required, the owner submits a complete retrofit plan set, generally including:

• Cover sheet and site plan
• Floor plans, elevations, and sections
• SWOF identification and justification of wall lines
• Structural calculations and lateral analysis
• Foundation plan and details
• Diaphragm analysis and strengthening where needed
• Verification and detailing for diaphragm aspect ratios (for example, 3:1 limits or mitigation)
• Required Culver City SWOF notes
• Tenant Impact Mitigation Plan, where applicable

3. Obtain permit and start construction, due three to four years after Notice

Once the City approves the retrofit plans, a licensed contractor pulls the building permit, and construction has to begin within one year of permit issuance, staying inside the overall three- to four-year window measured from the Notice date.

4. Complete construction, due five years after Notice

To satisfy the ordinance, the work must be finished, all required inspections passed, and the City must sign off the permit as “Final.”

What OC Structural Engineering Provides

Screening reports

• Field evaluation of the building’s soft-story conditions
• Identification of soft, weak, or open-front wall lines
• Evaluation of diaphragms, foundations, and lateral load paths
• Engineering determination of “Retrofit required” or “Exempt”
• Preparation of the formal screening documentation for the City

Retrofit plan sets

Prepared to meet Culver City’s SWOF requirements and typical reviewer expectations, which may include:

• Elevations and wall-line justification
• Full lateral system analysis
• Diaphragm design and ratio verification, with strengthening where necessary
• Foundation strengthening and new footings as required
• Beam and column upgrades
• Steel or wood special moment frame design
• Cantilevered column design in accordance with AISC provisions
• Collector and drag strut design in accordance with ASCE 7-16
• Material specifications and construction notes
• A coordinated structural calculation package

Permit and plan-check support

• Responding to Building Safety and SWOF reviewer comments
• Providing revised drawings and calculations when needed
• Preparing structural observation commitments and forms
• Supporting Housing Division clearance documentation when the project triggers it

Construction support

• Structural observation in accordance with Culver City CBC amendments and plan requirements
• Review of contractor RFIs relating to the structural design
• Site visits at key stages of the work
• Final observation letters or reports to support permit close-out

Why Soft-Story Retrofits Matter

Soft-story buildings are vulnerable during earthquakes because the ground floor often carries much less strength and stiffness than the levels above. Common issues include:

• Weak or open ground-floor walls due to parking or storefronts
• Large openings that shorten the effective length of shear walls
• Unreinforced or poorly detailed frames
• Irregular or discontinuous load paths
• Inadequate diaphragm support and chord detailing

These conditions can lead to excessive drift, localized failures, or collapse of the lower story in a strong earthquake. Culver City’s ordinance aims to reduce those risks, protect occupants, and preserve the city’s housing stock.

Culver City-Specific Considerations

Culver City reviewers typically look for:

• Clear identification and justification of SWOF wall lines
• Required cover-sheet notes and general notes specific to the SWOF program
• Compliance with material strength limitations and detailing requirements
• Appropriate structural observation commitments
• Shear wall lengths, drift limits, and seismic force-resistance system R-values that match code and local requirements
• Proper collector and drag strut design and detailing
• Foundation upgrades in line with CBC Chapters 18 and 19 as adopted and amended
• Anchorage and stability provisions for hillside or sloping sites
• Demonstrated continuity of the seismic load path from roof to foundation

Tenant notification and Housing Division requirements

For occupied buildings, Culver City may require:

• Written notification to current and prospective tenants
• Tenant protections when conditions become temporarily untenantable
• A Tenant Impact Mitigation Plan (TIMP) outlining how construction will affect residents
• Housing Division clearance before certain permits or work can proceed

OC Structural can assist with the engineering-related portions of these requirements and coordinate with property managers and ownership teams.

Capital improvement pass-through (optional for owners)

Culver City may allow owners to recover a portion of eligible retrofit costs through regulated rent increases, subject to:

• Timely application after project completion
• Documentation and verification of eligible costs
• Amortization limits
• Annual caps on rent increases

We can help document engineering and design-related expenses as part of a broader pass-through strategy.