Commercial / Seismic Strengthening
Seismic Strengthening NZ
New Zealand's earthquake-prone building legislation is driving a nationwide programme of seismic upgrades. NZ Concrete Group delivers structural strengthening work that brings buildings into compliance and protects lives, assets, and business continuity.
Discuss Your BuildingThe NZ Seismic Context
Under the Building (Earthquake-prone Buildings) Amendment Act 2016, territorial authorities across New Zealand are identifying earthquake-prone buildings and requiring owners to strengthen or demolish them within defined timeframes. Buildings rated below 34% of the New Building Standard (NBS) are classified as earthquake-prone.
For building owners, this creates an obligation — but also an opportunity. A well-executed seismic upgrade extends a building's economic life, protects tenants and the public, maintains insurance eligibility, and preserves property value. The alternative — neglecting compliance — leads to declining occupancy, rising insurance costs, and eventual forced closure.
Our Strengthening Approach
Every seismic strengthening project starts with understanding the existing structure and its deficiencies. We work alongside structural engineers to develop strengthening solutions that are practical, cost-effective, and minimally disruptive to building operations.
Initial Assessment Support
We work with your structural engineer to assess the existing building, identify structural weaknesses, and determine the current NBS rating. This forms the basis for developing a strengthening strategy.
Solution Design
We provide buildability input during the design phase, helping engineers develop strengthening details that are practical to construct and cost-efficient to deliver.
Construction Delivery
From demolition of existing elements through to new structural concrete, steel connections, and finishing. We manage the full physical strengthening programme.
Occupied Building Work
Many strengthening projects require work in occupied buildings. We plan staging, dust control, noise management, and access to minimise disruption to tenants and operations.
Strengthening Methods
The right strengthening approach depends on the building type, deficiency, target NBS rating, and budget. Common methods we deliver include:
Concrete Shear Walls
New reinforced concrete walls added to the existing structure to resist lateral earthquake forces. One of the most common and effective strengthening methods.
Steel Bracing
Steel cross-bracing or moment frames installed within existing bays. Often used where concrete shear walls are impractical due to space or access constraints.
Foundation Upgrades
New footings, ground anchors, or underpinning to transfer strengthening loads safely into the ground. Essential when new shear walls or bracing add load paths the existing foundations cannot carry.
FRP Wrapping
Fibre-Reinforced Polymer wraps applied to existing concrete columns and beams to increase ductility and confinement. Useful for improving the performance of brittle elements.
Diaphragm Strengthening
Upgrading floor and roof diaphragms to properly transfer lateral loads to the vertical bracing system. Critical in unreinforced masonry and timber-framed buildings.
Connection Upgrades
Strengthening wall-to-floor, wall-to-roof, and column-to-beam connections that may fail in an earthquake. Often the most cost-effective intervention per NBS percentage point gained.
Building Types We Strengthen
We have strengthened a wide range of commercial and public buildings across New Zealand, including unreinforced masonry buildings, pre-1976 reinforced concrete frames, tilt-up panel buildings, heritage structures, multi-storey office buildings, retail centres, schools, and hospitals.
Need to Strengthen Your Building?
Talk to us about your earthquake-prone building. We can review your engineering assessment and provide a construction cost estimate for the strengthening work.
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