Understanding Changes to New Zealand's Earthquake-Prone Building System

Essen

2 days ago

3 min read

Proposed earthquake-prone building changes are creating uncertainty for many building owners, landlords and investors. This article outlines what is changing, what remains uncertain and the practical steps owners should consider now.

Legislative Status Notice

These proposed earthquake-prone building changes represent one of the most significant updates to New Zealand's seismic building framework since the current regime was introduced.

Last Updated: 23 September 2026

This article reflects publicly available information regarding New Zealand's earthquake-prone building framework as at the publication date. Proposed legislative changes do not alter existing legal obligations until formally enacted.

Building owners should confirm current requirements with their local council and obtain project-specific engineering and legal advice before making decisions regarding compliance, strengthening or investment.

This article provides general information only and should not be relied upon as building-specific advice.

Why Are Earthquake-Prone Building Changes Being Proposed?

The current earthquake-prone building framework introduced a nationally consistent approach to identifying and managing potentially vulnerable buildings.

While the system improved consistency, concerns have emerged around:

Compliance costs
Impacts on town-centre investment
The focus on %NBS ratings
Whether current requirements properly reflect actual life-safety risks

The proposed reforms aim to create a more targeted and risk-based approach.

The Key Shift

Historically, much of the conversation has focused on:

"What is the building's %NBS?"

The proposed direction shifts the focus toward:

"What are the actual life-safety risks associated with this building?"

A percentage rating can be useful, but it doesn't always explain:

Why a building received that rating
What vulnerabilities exist
What strengthening may be required
Which improvements will provide the greatest benefit

What Building Owners Should Understand

Existing Assessments Still Matter

Proposed reforms do not make existing engineering information worthless.

Previous assessments often contain valuable information about:

Structural systems
Building vulnerabilities
Previous alterations
Potential strengthening options

Understanding a building remains valuable regardless of future regulatory changes.

Detailed Assessments May Become More Valuable

A Detailed Seismic Assessment (DSA) can provide much more information than a percentage rating alone.

A DSA can identify:

Critical structural weaknesses
Life-safety vulnerabilities
Areas of reserve strength
Practical strengthening opportunities

Rather than simply asking:

"What is my %NBS?"

Owners may increasingly ask:

"What are the actual risks and what should I do about them?"

What Should Building Owners Do Now?

Gather Existing Information

Locate any:

Previous engineering reports
Seismic assessments
Structural drawings
Building consent records
Strengthening documentation

Understand the Building

The most useful question is often not:

"What is my rating?"

but:

"What are the actual risks associated with this building?"

Avoid Rushing Decisions

For many owners, the best first step is:

Understanding existing information
Confirming current obligations
Obtaining practical engineering advice
Comparing realistic options

before committing to major expenditure.

Key Takeaways

✅ A building is more than a percentage rating

✅ Existing assessments still contain valuable information

✅ Detailed assessments can provide greater clarity on actual risks

✅ Regulatory requirements and structural risk are not always the same thing

✅ Good decisions start with good information

Need Advice on an Existing Building?

Whether you're reviewing a seismic assessment, considering a Detailed Seismic Assessment, planning strengthening works or trying to understand what the proposed reforms might mean for your property, Essen Engineering can help you understand your building and identify practical pathways forward.

Discuss Your Building With Us

What Building Owners, Investors and Landlords Need to Know

Published: September 2026

Prepared by: Michael Somerville, CPEng, IntPE, CMEngNZ