23 June 2022
Ref 2122-2230
Jack Hulls
[FYI request #19472 email] Tēnā koe Jack
Thank you for your request of 25 May 2022 to the Ministry of Business, Innovation and Employment
(MBIE), for the following information under the Official Information Act 1982 (the OIA):
Can you please provide information about the earthquake assessment of head office on Stout st.
Of interest is when was it last assessed and what was the result.
Any information about when another assessment will be done.
The Earthquake-prone Building (EPB) System under the Building Act 2004 uses %NBS (New Building
Standard) ratings and seismic assessments to determine whether buildings are deemed earthquake-
prone. A New Building Standard (NBS) score evaluates the likely performance of specific building
elements over a range of earthquakes, in terms of protecting life. A %NBS attempts to provide a rating for
the whole building, and represents how that building is likely to perform compared to an equivalent new
building on the same site. Under the Earthquake-prone Building System, a %NBS rating of less than 34%
means that the building is earthquake-prone. There are legislative obligations for building owners of
earthquake-prone buildings to remediate their building within a specific timeframe.
The %NBS was specifically developed to support the implementation of earthquake-prone building
legislation, however it is used more widely in the market for a range of other purposes. The aim of
the %NBS metric is to provide a relative assessment of seismic risk and is not a predictor of building
failure in any particular earthquake. While a low %NBS rating does convey a heightened life safety risk in
the event that an earthquake occurs, it does not mean that the building is unsafe. The purpose of seismic
assessments is to inform building owners and users about their building vulnerabilities, encourage
strengthening of vulnerable buildings and lead to the improvement of New Zealand’s building stock over
a reasonable time period.
I can advise that a Detailed Seismic Assessment of 15 Stout Street was completed by Aurecon New
Zealand Ltd in February 2012. The assessment found that 15 Stout Street had a maximum credible
capacity of approximately 180% of New Building Standard.
In your request, you note changes to the %NBS rating for Mātauranga House, the Ministry of Education’s
head office in Wellington. While assessments under the Earthquake-prone Building System under the
Building Act requires engineers carrying out assessments to use the Engineering Assessment Guidelines,
engineers undertaking seismic assessments for other purposes may voluntarily choose to use a revised
version of section C5 of the guidelines (known as “The Yellow Chapter”) when assessing concrete
buildings. I understand the change in %NBS rating for Mātauranga House was due to a new assessment
using the Yellow Chapter guidelines.
MBIE1376631
MBIE’s head office at 15 Stout Street was not constructed in the same way as Mātauranga House and
does not have precast floors; the building has reinforced concrete floors that were cast onsite. Because of
this, we don’t have any current intention to undertake a new seismic assessment.
If you are interested in finding more about the changes to the Guidelines, you can find more at
https://www.building.govt.nz/section-c5-concrete-buildings-proposed-revision.
Thank you again for your request. Under section 28(3) of the OIA, you have the right to refer my response
to an Ombudsman for review. You can find more about this by emailin
g [email address], or by
calling 0800 802 602.
Nāku noa, nā
Adrian Regnault
General Manager, Workplace
Ngā Pou o te Taumaru
