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133AC: Meaning of earthquake rating
or “This explains how strong a building is during earthquakes compared to new buildings”
You could also call this:

“This explains how to tell if a building is in an area with low, medium, or high earthquake risk based on a special number called the Z factor.”

The law divides areas into three levels of earthquake risk based on something called a Z factor. You can think of the Z factor as a measure of how likely and how strong earthquakes might be in an area.

If the Z factor is less than 0.15, the area has a low earthquake risk. If it’s between 0.15 and 0.3, the area has a medium risk. If it’s 0.3 or higher, the area has a high risk.

The Z factor is calculated using rules from the building code and other official documents. These rules were set on the day this law came into effect.

The earthquake risk level of an area affects two things:

  1. How quickly the local council needs to check buildings to see if they might be unsafe in an earthquake. The council also needs to tell the government how this work is going.

  2. How long building owners have to make their buildings safer if they’re found to be at risk in an earthquake.

You can find more details about the timelines for checking buildings in section 133AG, and about the deadlines for making buildings safer in section 133AM.

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Next up: 133AE: Meaning of priority building

or “This explains which buildings are considered important in emergencies and need special attention for earthquake safety.”
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Part 2 Building
Special provisions for earthquake-prone buildings: Application and interpretation

133ADMeaning of low, medium, and high seismic risk

  1. For the purposes of this Act, the area in which a building is located has—

  2. a low seismic risk if the area has a Z factor that is less than 0.15; and
    1. a medium seismic risk if the area has a Z factor that is greater than or equal to 0.15 and less than 0.3; and
      1. a high seismic risk if the area has a Z factor that is greater than or equal to 0.3.

        1. For the purpose of subsection (1), the Z factor of an area is the seismic hazard factor that would be used to design a new building on a site in that area in accordance with the following, as they relate to calculating Z factors and as they apply on the day on which this section comes into force:

        2. the building code; and
          1. verification methods; and
            1. standards incorporated by reference into the building code or a verification method.

              1. The seismic risk of an area affects—

              2. the time frame within which a territorial authority must—
                1. apply the EPB methodology to identify buildings or parts of buildings in the area that are potentially earthquake prone (see section 133AG); and
                  1. report to the chief executive on its progress towards that objective; and
                  2. the deadline for completing seismic work on a building or a part of a building in the area, if it is subject to an EPB notice (see section 133AM).

                    Notes
                    • Section 133AD: inserted, on , by section 24 of the Building (Earthquake-prone Buildings) Amendment Act 2016 (2016 No 22).