Non-Ductile Concrete Retrofit

NDC Seismic Retrofit

Seismic Retrofit Solutions for Vulnerable Concrete Buildings

ZDX Industries provides engineering, permitting, and construction services for non-ductile concrete retrofit projects throughout Southern California. Our team works with property owners, managers, and developers to evaluate existing structures, navigate city requirements, and deliver practical seismic retrofit solutions.

We have completed NDC retrofit projects for buildings subject to mandatory ordinances in the City of Los Angeles, City of Santa Monica, and City of West Hollywood — including some of the earliest projects completed under the LA ordinance.

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Background

What Is a Non-Ductile Concrete Building?

Non-ductile concrete buildings are typically older reinforced concrete structures designed before modern seismic codes were implemented. Many were constructed prior to the mid-1970s and may be vulnerable to brittle structural failure during a major earthquake.

Commercial Office Buildings

Multi-story office structures built before 1980 seismic codes

Apartment Buildings

Older multifamily residential concrete structures

Mixed-Use Properties

Ground-floor retail with residential or office above

Parking Structures

Concrete parking garages and podium structures

Institutional Facilities

Schools, hospitals, and government buildings

What We Provide

Our NDC Retrofit Services

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Structural Evaluation

Assessment of existing structural systems to determine retrofit requirements and compliance with applicable ordinances.

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Retrofit Design

Engineering and design of practical, cost-effective retrofit solutions tailored to the building's constraints and occupancy.

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City Permitting

Permit expediting and plan check coordination with LADBS, Santa Monica, West Hollywood, and other jurisdictions.

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Construction

Full retrofit construction including night-shift and phased operations for occupied buildings.

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Occupied Building Coordination

Tenant communication, work scheduling, and phasing strategies to minimize disruption during construction.

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Structural Observation

Licensed engineer structural observation and documentation to satisfy city inspection and project closeout requirements.

How It Works

Our 5-Step Process

Initial Building Review

We review available documents and conduct a site visit to assess the building and discuss the project scope.

Structural Assessment

Licensed engineers perform a detailed evaluation to determine retrofit requirements and develop a compliance strategy.

Retrofit Design

Our engineers design a practical, cost-effective retrofit solution and produce permit-ready construction documents.

Permitting

We manage plan check submission, agency coordination, and permit issuance to keep the project on schedule.

Construction & Closeout

ZDX performs all retrofit construction and manages final inspections and project closeout documentation.

Case Study

Featured NDC Project

1800 N Highland Avenue — Hollywood, CA

Non-Ductile Concrete Seismic Retrofit · City of Los Angeles

ZDX Industries completed the non-ductile concrete seismic retrofit of a fully occupied six-story commercial office building in Hollywood. Tenants at the time included Ticketmaster and Live Nation, requiring strict coordination to maintain normal business operations throughout construction.

This project was one of the earliest completed under the City of Los Angeles mandatory NDC retrofit ordinance. ZDX performed all work on night shifts to minimize tenant disruption, and adapted the retrofit design in the field to relocate an exterior shear wall that conflicted with building systems — delivering the project on schedule and within budget.

Rebar shear wall formwork — garage level P2

Rebar column cage and shear wall — garage P2

Exterior rebar — looking up building face from scaffold

Rebar grid detail — slab and beam reinforcement

Exterior rebar — shear wall along building face

Carbon fiber column wrap — interior ground floor

Interior rebar and steel framing — overhead view

Rebar shear wall — interior framing in progress

Carbon fiber beam wrap — occupied office above

Rebar shear wall and beam reinforcement — ceiling view

Scaffolding and debris netting — full building side

Scaffolding — canopy and exterior view from parking lot

Rebar shear wall — large garage level installation

Rebar grid — wall and slab reinforcement tunnel view

Carbon fiber column wrap — tenant space in use behind

Interior rebar wall — mid-construction with MEP rough-in

Interior corridor — rebar shear wall visible through doorway

Rebar wall — corner with ceiling grid and window light

Rebar wall and ceiling reinforcement — interior office floor

Completed garage level — painted shear walls and MEP

French Quarter — West Hills, CA

20969 Ventura Blvd — West Hills, CA

Non-Ductile Concrete Seismic Retrofit · City of Los Angeles

ZDX Industries performed the non-ductile concrete seismic retrofit of French Quarter, a retail commercial complex in West Hills featuring an open-air concrete parking structure. The retrofit scope included carbon fiber column and beam wraps throughout the parking levels and new reinforced concrete shear walls with full footing systems — all constructed with the parking structure remaining active throughout.

The project required careful coordination around the building's distinctive decorative ironwork screens and active parking operations. ZDX phased the work to keep the garage accessible during construction and delivered the project within the mandatory compliance window.

Common Questions

NDC Retrofit FAQ

Does my building need an NDC retrofit?

If your building is a concrete structure built before approximately 1980, it may be subject to a mandatory retrofit ordinance in Los Angeles, Santa Monica, or West Hollywood. ZDX can review your building and confirm whether it falls under an applicable ordinance.

How long does an NDC retrofit project take?

Project timelines vary depending on building size, complexity, and occupancy. Most projects range from 6 to 24 months from initial evaluation through construction completion. ZDX works efficiently to meet ordinance compliance deadlines.

Can the building remain occupied during retrofit construction?

Yes. ZDX has extensive experience completing NDC retrofit projects in fully occupied buildings. We use phased construction schedules, night-shift operations, and tenant coordination strategies to minimize disruption throughout the project.

What is the cost of an NDC retrofit?

Retrofit costs depend on the building's size, structural system, occupancy, and the specific retrofit measures required. ZDX provides free initial consultations and can prepare preliminary cost estimates following a structural review.

Does ZDX handle both engineering and construction?

Yes. ZDX provides integrated engineering and construction services, meaning we manage the entire project from structural evaluation and retrofit design through permitting and construction completion. This single-source approach streamlines coordination and reduces project risk.