AUT experts on new earthquake rules

Government changes to the earthquake-prone building system will remove nearly 3000 buildings from the classification.

Following the Seismic Risk Management Review, Building and Construction Minister Chris Penk says the system is being refocused to reduce repair costs and prevent buildings from being left empty and derelict.

The Science Media Centre asked experts, including Auckland University of Technology's Dr Esther Aigwi, Associate Professor Shahab Ramhormozian and Professor John Tookey, to comment.

Dr Esther Aigwi, Senior Lecturer - Built Environment Engineering, comments:

"The new earthquake prone building system significantly advances building resilience by encouraging owners to invest in their properties. The '4-option' framework offers flexible pathways, allowing for incremental improvements or opting out of regulations, while prioritising life safety and addressing potential building failures.

"By redefining 'priority buildings' and introducing change-of-use requirements, the new system encourages more owners to strengthen their structures. This presents an important opportunity to enhance safety and durability instead of disengaging. Overall, these changes promote a constructive mindset towards building resilience and safety, benefiting both owners and the community.

"However, after reading the terms of reference document for this review, released in May 2024, I noticed some gaps, particularly regarding questions related to 'Regulatory responses.' It would be beneficial for the review to explore how social connections and community ties to earthquake-prone heritage buildings may affect compliance with the current earthquake-prone building legislation. Research indicates that New Zealand communities with a 'stronger attachment to place' are likely to value their heritage buildings and prioritise their conservation efforts. The social cohesion that exists within such communities would make them more willing to invest in mandated repairs.

"Another significant gap is that the terms of reference did not explore questions regarding diverse challenges faced by urban vs regional areas under the scope of 'Barriers to remediation.' Research has shown that regional centres in New Zealand, which often contain a higher density of unique earthquake-prone heritage buildings per capita, frequently receive less financial support than their urban counterparts, where fewer of these buildings exist. This discrepancy can result in the abandonment of vital heritage structures in regional centres as an unintended consequence of the legislation, ultimately leading to a decline in the overall vitality of regional inner-cities."

Dr Shahab Ramhormozian, Associate Professor in Structural and Earthquake Engineering, comments:

"Developing an effective system for managing earthquake-prone buildings (EPBs) is a complex task due to the multifactorial nature of the problem and the inherent uncertainties involved. While the original EPB framework was a commendable effort, its implementation over time, and ongoing engagement among industry professionals, academics and researchers, clients, building owners, and policymakers, highlighted the need for refinement.

"The original system classified New Zealand into three seismic risk zones (low, medium, high) and set timeframes for identifying, retrofitting, or demolishing EPBs. Buildings were assessed based on their percentage of compliance with the New Building Standard (%NBS), with those scoring 34% or less deemed earthquake-prone and subject to mandatory action. This led to many buildings falling under the EPB category.

"The recently reviewed system addresses the challenges of the original framework and appears to be a significant improvement. It introduces two EPB categories:

• Unreinforced masonry buildings with unsecured facades or walls facing public areas or neighbouring properties to be automatically considered EPBs.
• Concrete buildings of three storeys or more to be assessed using a new targeted retrofit methodology, replacing the %NBS approach.

"Additionally, the revised system introduces four levels of mitigation requirements depending on each building's specific needs, type, and location rather than enforcing a uniform %NBS threshold. These changes make the system more risk-based, realistic, and effective in practice.

"Although I am an academic who typically favours detailed numerical assessments, I found the %NBS system not ideal given the uncertainties involved. The revised approach seems to prioritise high-risk buildings and to offer a simpler, more targeted retrofit process and plan. It is expected to be more cost-effective and practical than its predecessor."

Professor John Tookey, AUT School of Future Environments, comments:

"The changes introduced around earthquake prone building (EPB) legislation is an inevitable consequence of the original policy introduced in 2017. The intention at the time was to identify and prioritise buildings that may present a risk to the general public - particularly in highly trafficked situations such as schools, hospitals etc. This is entirely the right thing to do. But while the effect on the private sector was problematic for individual building owners, the problem to address in the public sector was substantially greater. Construction engineering ultimately is focussed on ensuring public safety. However the methodology adopted in EPB identification and prioritisation inadvertently identified more EPB than may have been originally considered. This presented a significant problem to both the previous government - who introduced it - as well as the current government. Once a building has been identified as EPB, there is not an unreasonable expectation of government entities having a plan in place to rectify the problem and preserve public safety. Under the previous government, developing a rectification plan was largely avoidable since buildings were still in the process of being assessed and evaluated for EPB status. However, under the new government, the evaluation period has largely passed. Hence commitments to construction and upgrade expenditure needs to be more explicit.

"The current government response has been to further kick the can down the road. On the one hand, the government's budgetary austerity measures preclude wide ranging investment in public building stock. On the other hand, no government wishes to be accused of disregard for public safety. Hence the policy approach as outlined in today's announcements has been twofold. Firstly to substantially extend the assessment period for EPB. Secondly to move the goal posts for what counts as an EPB to reduce the expectation of remediation measures in current and future budgets. A cynic may observe that the extension of 4 years introduced in November 2024 is coincidentally sufficient to push any funding decision out to the next but one parliament - making the problem potentially someone else's politically.

"In fairness to all players involved, the new measures of assessment for EPB make a lot of sense in how they are structured. Unreinforced masonry structures, parapets on buildings and similar are significant public risk factors presenting an obvious priority to work on. Similarly the requirement to prioritise structures in built up areas with high levels of public access makes a lot of sense. These measures are to be commended. Overall the changes in policy represent a pragmatic understanding of the requirements for upgrade presenting a significant strain on the private sector, as well as a huge drain on the public purse. Notwithstanding which, none of these measures will ultimately change the eventual need to refit and strengthen buildings to ensure public safety. It is something of a shame that the opportunity, in the current difficulties that the construction industry faces, to introduce industry stimulation measures was missed. Providing partial grants and preferential loans to undertake such works could have had a significant stimulation effect on the economy. Stimulating this sort of work has huge benefits. Firstly in the form of public safety. Secondly in that none of it is ever going to get any cheaper for clients or government to undertake - no matter how frequently the rules are changed and how far down the road the can is kicked."

Useful links

• Science Media Centre website
• Study Built Environment Engineering at AUT
• Dr Esther Aigwi academic profile
• Associate Professor Shahab Ramhormozian academic profile
• Professor John Tookey academic profile