Much more needs to be done to protect workers and residents in the capital, Wellington Central's MP says after a damning report was released showing there could have been fatalities in Statistics House during the Kaikoura Quake had it happened during office hours.

Labour MP Grant Robertson is backing the report's recommendations for a review of design standards, updating of building laws, and investigation of buildings of a similar design and age.

"I know the public servants that have worked in those buildings want to be sure that they're safe and secure places," Robertson said. "For most Wellingtonians this isn't a problem, but for those that are affected they take it very seriously and they want answers."

Robertson wants to know why people were even working in the building when critical work still needed to be done.

The report says that in 2013 the owners of the building, Centreport, received a report that recommended as a 'critical element' strengthening floor units at the four corners of the building.

Robertson said the work had been completed on one floor - and that floor did not sustain damage.

"However the floors where no work had been done at all, they were the ones where we had the catastrophic collapse of the beams. Centreport have got a serious set of questions to answer."

The government has moving to alter two building standards and is asking the Ministry of Building, Innovation and Employment if it needs more powers under the Building Act.

Building and Construction Minister Nick Smith said it was unacceptable that the damage at Statistics House could have killed people.

"This quake was large and unusually long, but a modern building like Statistics House should not have had life-threatening structural damage," he said.

"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.

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.

"It's been confirmed that frames can elongate, or stretch if you like, and it's now it a matter of changing some of our codes to take account of these learnings."

Campbell said the Canterbury earthquakes led to Building Code changes - and now more changes are likely given what we have learned from the Kaikoura earthquake.

"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.