Under the Building Act 2004 Council is required to assess the earthquake risk of certain buildings within the district. Buildings that are determined to be earthquake-prone are required to be strengthened or demolished within specific timeframes set by the legislation.
In general, the provisions only apply to non-residential (being commercial or industrial) and some larger residential buildings.
The Building (Earthquake-prone Buildings) Amendment Act 2016 introduced major changes to the way earthquake-prone buildings are identified and managed under the Building Act.
The system is consistent across the country and focuses on the most vulnerable areas and buildings in terms of people's safety.
Buildings are regarded as earthquake-prone if they are assessed as being less than one-third of the strength required for a new build in the same location in moderate earthquake shaking.
This assessment is expressed by a “score” in terms of the percentage of New Building Standard achieved (%NBS).
Earthquake-prone buildings have a %NBS of less then, or equal to, 33%NBS.
Managing earthquake-prone buildings
Alongside the change in legislation, a new national system for managing earthquake-prone buildings came into effect on 1 July 2017.
The new system affects owners of earthquake-prone buildings, local councils, engineers, other building professionals and building users.
The new system means:
- local councils must identify potentially earthquake-prone buildings
- owners who are notified by their local council must obtain engineering assessments of the building carried out by a suitably qualified engineer, this will confirm or disprove councils initial identification
- local councils use the engineering assessment to determine whether buildings are earthquake-prone, assign ratings, issue notices and publish information about the buildings in a public register
- owners are required to display notices on their building and to remediate their building.
The Building Act also divides New Zealand into three seismic risk areas – high, medium and low.
An overview of the system including seismic risk areas and time frames can be found on the Ministry of Business, Innovation and Employment (MBIE) “building” website.
What this means for Waikato District
Our district spans across a medium and low seismic risk area, a map of which can be found under related documents at the end of this page. That means our Council has between 5 and 10 years (from 1 July 2017) to identify potentially earthquake-prone buildings within our district.
For information on the methodology used, visit the MBIE website.
Council will inform building owners of a potential earthquake-prone status of their building. Building owners have 12 months to respond to this notice, that is, to confirm or disprove this status.
This will generally require an engineering assessment for their building.
If Council determines that a building is earthquake prone, it needs to:
- assign an earthquake rating for that building,
- issue an earthquake-prone buildings notice to the owner to display prominently on the building, and,
- publish the building information on the earthquake-prone buildings register.
Owners of earthquake-prone buildings who have received a notice must take action within set time frames. The time frames depend on whether the building is a priority building, and the seismic risk area that the building is located in.
Because Waikato district spans across a medium and low seismic risk area, the timeframe to carry out seismic work on buildings identified as an earthquake-prone building between 12.5 and 35 years.
Earthquake-prone buildings in Waikato District
Council is working through the buildings in our district to identify those that are potentially earthquake-prone buildings.
Our Building Quality team is undertaking the initial assessments and will notify building owners if their building is potentially an earthquake-prone building.
If you receive a notice from Council that your building may be an earthquake-prone building you will have one year to respond.
Guidance on the approach you may take can be found on the MBIE website.
The same process is being followed to assess Council’s own buildings. We are approximately half way through completing initial assessments on our affected building stock.
A list of Council-owned buildings that have been identified as earthquake prone buildings will be loaded on this page soon.
This list will be a working list and subject to change as further assessments are undertaken or as strengthening works are completed.
There will be a separate list of privately-owned buildings identified as earthquake-prone as required under legislation. This will be published on this website once inspections are under way.