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Seismic Retrofit

Our seismic retrofit team consists of highly expert structural Engineers with long-term experience in retrofit design of more than hundred buildings in South California

They provide our clients with the most optimized and cost-efficient retrofit solutions

CES4 has been one the most active engineering consultants in the Los Angeles area involved in the structural assessment and retrofit design of buildings identified for mandatory seismic retrofit program in the region.

CES4 has completed more than 100 retrofit design projects as part of City of Los Angles Soft Story Program

CES4 has been involved in the Structural Assessment and Retrofit Design of several Voluntarily Seismic Retrofit projects and as part of Mandatory Retrofit Program of City of Santa Monica and West Hollywood

City of Los Angeles Mandatory Retrofit Programs

Ordinance 183893 requires the retrofit of pre-1978 wood-frame soft-story buildings and non-ductile concrete buildings. The goal of the mandatory retrofit programs, under the ordinance, is to reduce these structural deficiencies and improve the performance of these buildings during earthquakes. Without proper strengthening, these vulnerable buildings may be subjected to structural failure during and/or after an earthquake:

Soft-Story Program:


  • 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

Non-ductile Concrete Retrofit Program

Buildings that are within the scope of this ordinance and require retrofitting are concrete buildings with a roof and/or floor supported by a concrete wall or concrete column, constructed before January 13, 1977.


  • 3 years: Submit completed checklist for review to determine if building is a non-ductile concrete building
  • 10 years: Submit proof of previous retrofit, or plans to retrofit or plans to demolish building
  • 25 years: Complete construction

City of Santa Monica Retrofit Program

City of Santa Monica’s Seismic Retrofit Ordinance was approved on March 28, 2017 which encompasses 20 years of work to increase the safety of earthquake-vulnerable buildings in the event of a large quake. As part of this ordinance, nearly 2,000 commercial and multi-family residential buildings need to be assessed for possible structural improvement.

Compliance Time Frame

City of West Hollywood Retrofit Program

  • Ordinance 17-1004
  • Mandatory Strengthening for Existing Wood-Frame Buildings with Soft, Weak, or Open-Front Walls.
  • Voluntary Strengthening Provisions for Cripple Walls and Sill Plate Anchorage in Existing Wood-Frame Buildings.
  • Ordinance 17-1011

for existing Non-Ductile Concrete and Pre-Northridge Steel Moment Frame  Buildings


  • The ordinance for Soft Story buildings will become effective on April 1, 2018.
  • The ordinance for Non-Ductile Concrete and Pre-Northridge Steel Moment Frame Buildings will become effective on August 7, 2018.