Since the devastating Christchurch earthquake in 2011 and the 2016 Kaikōura event, New Zealand’s approach to concrete building safety has changed dramatically.
These disasters exposed weaknesses in many structures and inspired a wave of research, updated rules, and practical solutions designed to better protect lives and property.
New Zealand’s Building Code ranks among the toughest when it comes to earthquake resilience. These standards are regularly updated to reflect advances in science and engineering.
One key area of focus has been the seismic assessment of concrete floors in multistorey buildings—especially after widespread issues were uncovered in precast concrete floors.
Following the Kaikōura quake, the ReCast Floors project began, targeting a known problem with hollow core slabs commonly used here. Investigations showed that around 150 buildings in Wellington had potentially critical design flaws in their precast floors.
This discovery prompted a significant update to Section C5 of the Seismic Assessment Guidelines in 2025. Industry experts and researchers worked together to improve the clarity and effectiveness of these rules, helping engineers better identify and mitigate risks.
A new national guide has been launched to help engineers assess the earthquake readiness of concrete floors with greater precision.
Drawing on recent earthquake data, local research, and international best practices, this guide offers detailed tools to evaluate how forces travel through a building’s floor system.
Beyond emergency fixes, it supports longer-term planning and smarter building designs.
Modern seismic upgrades aim to stop serious damage during quakes, allowing buildings to stay operational afterwards.
These improvements often use low-damage techniques like advanced joint systems, devices that absorb energy, and ductile detailing that lets parts flex instead of break.
Such features reduce repair costs and downtime, a huge benefit for offices, hospitals, and schools.
With many older buildings needing upgrades, engineers have developed affordable strengthening methods that don’t compromise function.
Heritage buildings, in particular, pose a challenge, as any work must respect their historic appearance.
Solutions like targeted bracing, improved foundations, or discreet wall anchors make it possible to protect these treasures without altering their character.
Owners of buildings rated below 34% of the New Building Standard (NBS) face legal timelines to fix earthquake risks, which differ across regions.
Usually, the process starts with a thorough seismic assessment by qualified professionals. This may lead to detailed engineering plans and retrofit work.
Getting quotes from experienced experts familiar with the latest requirements is vital. Ignoring or delaying upgrades after receiving an Earthquake-Prone Building notice can lead to fines—and more importantly, endanger occupants.
Typically, strengthening a building involves these steps:
1. Conducting a structural assessment and drafting an engineering report
2. Creating a tailored strengthening plan
3. Obtaining council consents and any necessary approvals
4. Carrying out the retrofit with qualified contractors
5. Completing final inspections and gaining compliance certification
Costs vary widely based on complexity. Minor upgrades might cost between $15,000 and $50,000, while major commercial retrofits can exceed $300,000.
Early assessment helps keep costs down, and grants may be available, particularly for protecting heritage sites.
New Zealand continues to lead in creating safer concrete structures through science-led methods and smart engineering.
Each quake teaches new lessons, pushing standards higher and helping communities face the future with greater confidence.
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