Earthquake-prone buildings

New rules are being developed around the definition of earthquake-prone buildings and the requirements for them to be seismically strengthened.

The Building (Earthquake-prone Buildings) Amendment Act, passed in May 2016, brings more direction from central government and less reliance on individual territorial authorities developing their own policies. TA’s still hold the responsibility for administering the law in their area, however.

Among the changes:

  • A new national register of earthquake-prone buildings will be developed, including information on the earthquake ratings of the buildings. This will be publicly accessible.
  • A new document will be developed, the Earthquake-Prone Building (EPB) methodology. This will set out how TAs can identify earthquake-prone buildings. The document will include a profiling tool and engineering guidelines for making seismic assessments.
  • The threshold for defining an earthquake-prone building remains, with amendments including that it can apply to parts of buildings. (An earthquake-prone building is often referred to as one that is less than 34 % of the new building standard.)
  • EPB notices, which show earthquake ratings, must be placed on earthquake-prone buildings.
  • New Zealand will be divided into 3 seismic risk areas – low, medium and high – based on the seismic hazard factor (‘Z’ factor).
  • Based on these risk areas, there will be targeted timeframes for TAs to identify earthquake-prone buildings and for owners to strengthen or demolish them:
    – Timeframes for identifying potentially earthquake-prone buildings are 5, 10 and 15 years.
    – Timeframes for strengthening earthquake-prone buildings are 15, 25 and 35 years.
    • A new category of priority buildings in medium and high-risk areas will be defined. These buildings – schools, emergency facilities etc. – must be identified and strengthened in half the time. Unreinforced parapets and facades on public thoroughfares must also be upgraded in half the standard timetable.

        The exact date the new law will come into effect has not yet been set, but it will be within the next 2 years.

        BRANZ has developed an online resource around seismic resilience.