Statistics House, which was badly damaged in the November 14 Kaikoura Earthquake. Photo / Mark Mitchell.
Statistics House, which was badly damaged in the November 14 Kaikoura Earthquake. Photo / Mark Mitchell.
The damage to Statistics House in November's Kaikoura earthquake has been blasted as "unacceptable", with building codes now set for review.
Several buildings in Wellington faced major damage in the quake, but Statistics House was particularly serious, due to the partial collapse of three floor units in the building.
A large beam in the ground floor also collapsed.
The results of Government review have just been released.
Building and Construction Minister Nick Smith said the damage at Statistics House could have killed people, and that was unacceptable.
CentrePort buildings (from left) Maritime House, Statistics House and Shed 35, damaged by the Kaikoura Earthquake. Photo / Mark Mitchell.
"This quake was large and unusually long, but a modern building like Statistics House should not have had life-threatening structural damage.
"We need to follow up on similarly designed buildings through councils and engineering companies, so that where it is a problem, it can be rectified.
"This has already been done in respect of Wellington as a consequence of the preliminary findings in Statistics House but now needs to be followed up elsewhere."
Smith said the Concrete Structures Standard would need amending, to ensure even new buildings were ready to withstand long earthquakes.
The Ministry of Business, Innovation and Employment (MBIE) has been instructed to look at whether additional powers are needed in the Building Act, to allow it to force building owners to address serious technical problems.
The Earthquake Actions Standard would also need review.
"A compounding factor was the geological basin effects that are not well understood, but which have also been observed in other earthquakes internationally," Smith said.
"This is an area of seismic science that needs further research, particularly in respect of Wellington."
Government Statistician Liz MacPherson said she hoped the investigation prevented future failures of this kind.
She added that it drove home the need for independent technical advice.
"I remain forever grateful that the quake struck after midnight when no one was in Statistics House.
"It is my hope that Centreport and their insurers can now accelerate decisions regarding the future of Statistics House.
"Staff who worked in the building are keen to know what's going to happen."
Centreport chief executive Derek Nind said the report gave some "much-needed answers".
However, Centreport still hadn't made a decision on the future of Statistics House, as it was waiting for the engineers and insurers to complete their work.
Work was also being done to assess the future of the nearby BNZ Building, Customs House and Shed 39.
Structural Engineering Society spokesperson Paul Campbell said the Kaikoura quake had shown flaws in the building code, for quakes that were both large and long.
"Flexible frames are designed to bend so that the ends of the beams experience controlled damage.
"But the Kaikoura earthquake has confirmed that if an earthquake is strong enough and long enough, the damage can make the beams grow in length.
"This means the supports for the pre-cast floor system can move too far apart, potentially causing parts of the floor to lose their support and collapse."
He said engineers were now working with MBIE on how buildings could be assessed and retrofitted to withstand these conditions.
Wellington City Council was given additional powers by the Government following the November quake, to order additional engineering reports.
The council has already used the new powers to order invasive testing of 80 buildings throughout the capital.
