Find out if your building is earthquake-prone
A nationwide policy for managing earthquake-prone buildings was introduced in July 2017. Buildings across the country are now managed in a consistent way. And more information is available to people using these buildings.
Whether a building is considered earthquake-prone, and is subject to the Building Act, is determined by its seismic resistance capacity. This capacity is calculated by an engineer. It is given as a percentage of the current new building standard (NBS). If a building’s seismic resistance capacity is calculated as less than 34% NBS, it is considered earthquake-prone.
Identifying and assessing buildings
Councils are responsible for identifying buildings as potentially earthquake-prone and telling building owners.
If your building is identified as potentially earthquake-prone, you will need to:
- engage an engineer to provide an engineering assessment for your building
- give the engineering assessment to your council within 12 months of being notified.
You may also consider selling. The obligation for strengthening the building would pass to the new owner. Or you may consider demolition. If your building has heritage value, restrictions will probably apply for any demolition work.
If you don’t provide an engineering assessment within the required timeframes, your council will determine that your building is earthquake-prone by default.
Building owners can also get an engineering assessment completed voluntarily; you don’t have to wait to receive notification from your council.
Comparing seismic assessments
If you commission a seismic assessment of your building and the findings differ to a previous assessment, what should you do?
Seismic assessments require a high level of professional judgement, so some difference of opinion between engineers is to be expected.
However, if significantly different assessments exist for the same building, then Engineering New Zealand (a national body representing professional engineers) recommends the engineers work together to resolve the issues.
Sometimes though, in complex or historical situations, engineers aren’t able to reach a solution by themselves. If you find yourself in this situation, Engineering New Zealand now offers a Seismic Assessment Reconciliation service, which is designed to help engineers reach an agreement and provide you with clarity.
Deciding if buildings are earthquake-prone
Your council will consider the engineering assessment and determine if all or part of your building is earthquake-prone.
If your building is confirmed as earthquake-prone, the council will:
- assign an earthquake rating for your building
- provide you with an earthquake-prone building notice, which you will be required to display on your building
- add your building to the earthquake-prone building register, a publically accessible list of earthquake-prone buildings.
If a building is not formally defined as earthquake-prone there are still many benefits in strengthening it. These include protecting your investment, and retaining a piece of New Zealand heritage for future generations.
Managing earthquake-prone buildings
The earthquake-prone building notice will outline the timeframes for bringing your building up to the required building code. You will need to consider the options for your building and make a plan.
Contact your local council to find out more about their process for assessing earthquake-prone buildings.
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