How we assess and manage earthquake-prone buildings

Find out about our process for dealing with earthquake-prone buildings, from identification through to strengthening.

What earthquake-prone means

A building, or part of a building, is earthquake prone if it is likely to collapse and cause injury or death, or damage to another property, in a moderate earthquake.  A moderate earthquake would generate a third of the level of shaking used to design a new building at the same site.

Earthquake-prone buildings are given an earthquake rating, commonly referred to as a percentage of the new building standard (NBS). Earthquake ratings mean the degree to which the building, or part, meets the seismic performance requirements of the Building Code. Buildings that achieve less than a third of the new building standard (below 34% NBS) are considered earthquake-prone.

The earthquake-prone building process

In May 2016, Parliament amended the Building Act 2004 to introduce a nationally consistent approach to the assessment and management of earthquake-prone buildings, including standardised notices and a national public register. This earthquake-prone building process came into force on 1 July 2017.

The earthquake-prone building process can be summarised in five steps:

Identification:

Assessment:

  • Owners of potentially earthquake-prone buildings will then provide more information about their building to the Council.
  • The Council will then confirm whether the building is earthquake-prone or not.

Notification:

  • Owners of earthquake-prone buildings will receive confirmation from the Council and will be issued an earthquake-prone building notice with a deadline to strengthen or demolish.

Seismic work:

  • Owners of earthquake-prone buildings will then carry out seismic work to ensure that their building is no longer earthquake-prone. Fixing an earthquake-prone building involves seismic work. This normally involves strengthening, demolishing, or partially demolishing the building.

Removal of the notice:

  • The owners will notify the Council once seismic work has been completed and a code compliance certificate has been issued. The Council will then review the work and inform the building owner that the building is no longer considered earthquake-prone. The notice can then be removed from the building.

An earthquake-prone building notice must be displayed on the main entrance/s to a building, informing the public that it is earthquake-prone, until Council officially notifies the owner the notice can be removed. 

A notice also shows the deadline by when a building must be fixed. The time frame for most buildings in Wellington is 15 years, however, buildings that have been identified as priority buildings have 7.5 years.

What this means for buildings identified before 1 July 2017

The national earthquake-prone building process replaces Wellington City Council’s previous earthquake-prone building policy:

If, before 1 July 2017, your building was identified as:

  • requiring assessment or as a potentially earthquake-prone building – the Council will review your building to check whether it falls within scope of the new earthquake-prone building process. We will then notify you of the outcome, and if the building is still potentially earthquake-prone you will then have 12 months to provide more information about your building to the Council.
  • an earthquake-prone building – the Council will review your building to check whether it falls within scope of the new earthquake-prone building process. We will then notify you of the outcome. If the building is still within scope we will issue you an updated earthquake-prone building notice. If the building is no longer within scope we will uplift the earthquake-prone building notice, although we will keep information about the building’s seismic performance on file.

The process of reviewing buildings identified under the Council’s previous earthquake-prone building policy will take several months. We are intending to have around half of these buildings reviewed by the end of 2019, with the remainder to be reviewed during 2020.

Need help?

Email: buildingresilience@wcc.govt.nz 
Phone: 04 499 4444

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