Expert panel told Wellington's Statistics House not built to design

Wednesday, 4 July 2018

Demolition of Statistics House in Wellington in early 2018 revealed new information about its partial collapse during the 2016 earthquake.

New information which came to light during the demolition of Wellington's Statistics House shows it was not built to design.

An investigation into the partial collapse of building was reopened in April, after an engineering consultant wrote a letter to the Ministry of Business, Innovation and Employment (Mbie) outlining differences between the design and the building itself.

However, an expert panel, which was reconvened to consider the new information, found that despite the inconsistencies between design and build, the original conclusions about the primary cause of the collapse remained unchanged.

According to the letter, the engineer found the lip, which supports the floor beams, measured about 40mm. The drawings show that should have been between 50mm minimum and 75mm maximum. The concrete structures standard recommends 60mm.

* MBIE reopens inquiry into partial collapse of Statistics House**

Demolition engineers examined a number of concrete beams after they had been removed from the building, as it was too dangerous to investigate them before the demolition.

From the ones they measured, about half were less than 50mm.

Statistics House, on Wellington's waterfront, was badly damaged in the 2016 Kaikoura earthquake.

It is unclear where the beams sat in Statistics House prior to the quake, because no information was recorded by the demolition engineer or contractor as to their original location.

The new information has led to three new recommendations. The ministry has agreed to most points.

First, the panel recommended the ministry work with Engineering New Zealand and its technical societies to review existing guidance and make sure the vulnerabilities of these building types are adequately communicated to the building sector.

Mbie will also review existing guidance for rapid post-disaster building assessment.

An industry-led initiative was also underway to develop New Zealand-specific guidance on how safety-in-design needs to be considered for the full extent of a building's life.

The ministry will also consider whether it is appropriate to review standards cited in the building code compliance documents, or alter other parts of the building code system.

Statistics House partially collapsed during the Kaikoura earthquake in November 2016.

The building was part of a major venture by CentrePort to expand into commercial property, which also included Customs House and BNZ Harbour Quays.