Inspections of buildings which look to have serious damage are expected to happen on Tuesday, RNZ's Adam Bennett reports.

The Government Statistician is demanding answers about why her department's relatively new headquarters could have suffered such major structural damage.

In a video post to staff posted on the Statistics New Zealand Facebook page, Liz MacPherson said she would be thankful "forever" that the quake had not happened when her staff were inside.

"I want to start off by saying how thankful I am that the earthquake happened at midnight and not at midday and that none of you were in the building. It's something that I will be forever grateful for," McPherson said.

It appeared that there had been structural damage to two floors of the building at the "stadium end".

"I am asking the same questions that I am sure you are asking. How is it that a building that is a new as Stats House, with the [earthquake] code rating it had could suffer this sort of damage. I'll continue to ask those questions."

MacPherson said she had been told staff could not return for anything between a few months and a year.

"I'm taking that as structural engineer speak for 'I don't know at this time'," MacPherson said.

Concrete beams in the Statistics New Zealand building were ripped from the outside of the building causing the ceilings to partially collapse, owners CentrePort has said.

KEVIN STENT/FAIRFAX NZ On Monday CentrePort refused to allow photographers to get close enough to Statistics House to see inside.

The owner of the Port of Wellington and a string of commercial buildings on reclaimed land has just released a statement about the state of some of its properties.

Statistics New Zealand said on Monday evening that damage to the building may mean staff are not back in its headquarters for a year, but CentrePort had refused to answer questions.

In a statement released by public relations firm SenateSHJ, CentrePort chief executive Derek Nind said that both Statistics House and Shed 39 – home of the Greater Wellington Regional Council (GWRC) - required more detailed inspections.

Nind said the upper floors of Statistics House, which had recently been upgraded, performed well, but there was substantial damage elsewhere.

"A small part of the ceiling on the ground floor and the first floor have partially dislodged after two concrete beams became separated from the exterior wall of the building."

CentrePort has not said exactly how "small" the piece of ceiling which collapsed was.

As well as Stats NZ, the building houses a cafe and staff from several other government departments.

The Shed 39 building "suffered damage to the ground floor", Nind said.

GWRC chairman Chris Laidlaw has said the ground floor of the building sunk around six inches, caused by liquefaction.

CentrePort said two of its other commercial buildings – the BNZ and Customs House – "performed well" although it was not clear when the tenants would move back into the buildings.

BNZ has said it's principal building in Wellington has been declared structurally sound. The building was closed for months after the 2013 earthquake.

"[U]nderstandably there has been damage to the building – things like cracks and fallen plasterboard and broken glass, which isn't unusual with a quake this size," BNZ said in a statement.

"It will take some time for us to go through the building, do the repairs and clean work areas. We're not expecting that our people will be back in the building this week."

A spokeswoman was not able to say whether employees would have been injured if the earthquake had occurred during work hours.

On Monday, in response to questions about the decision to move workers back into the BNZ following damage caused in 2013 (a quake which luckily also occurred out of work hours), CentrePort defended its action as a landlord.

"CentrePort is a responsible landlord with safety as its top priority. We always work closely with our tenants to ensure all buildings are safe before they are re-occupied after an emergency like an earthquake."

Statistics New Zealand has said its release of official figures is likely to be disrupted in the near future.

Justice House, headquarters of the Ministry of Justice and ACC, as well as home to Crown Law and parts of the Ministry of Education is closed "until further notice".

A number of other major Wellington buildings also remain closed yesterday, including the Ministry for Primary Industries (MPI) headquarters, Pastoral House on the Terrace and Pipitea House, the home of New Zealand's principal spy agencies and the Department of Prime Minister and Cabinet.

A spokeswoman for MPI said engineers were in the process of inspecting Pastoral House.

"We are expecting a full report on the building within the next day. In the meantime, staff are being advised not to enter any MPI building in the affected areas, including Pastoral House, until clearance is given."

Staff were being advised to work from home where possible.

"A small MPI team is working from the [MPI's] Wallaceville campus to ensure key ministry functions are maintained. Wallaceville, along with MPI's Sir William Pickering Drive office in Christchurch and Nelson buildings, has been inspected and cleared."