Three city council building inspectors appear to have been mistaken for engineers during an assessment of the Canterbury Television building after the September 4, 2010, earthquake.
The assessors spent up to an hour performing a level 2 rapid assessment on the building on September 7 after an external inspection two days earlier.
They gave the building a green placard, meaning it was safe to occupy, even though some floors could not be reached because they were locked.
A "boss" in reception when they arrived about 11.45am was probably CTV managing director Murray Wood or building manager John Drew, but this could not be confirmed.
Wood sent an email to all CTV staff at 1.26pm on September 7.
It read: "We have just had an internal inspection of the building from 3 engineers and they have found the building is in good condition and is deemed habitable. The only damage they could find was surface damage and has [no] effect on the stability of the structure.
"There is advice in the media that there will be more aftershocks so we need to be mindful that the situation may change at any time but on the recommendations of the experts from the agencies involved it's businesses as usual at CTV.
"If anyone has any anxieties or issues please come and see me directly."
An engineer eventually inspected the building and gave it the all-clear.
Wood died in the building collapse.
Top floors were locked
Top floors in the CTV building could not be inspected after the September 2010 earthquake because they were locked, the royal commission has heard.
There was no engineer on the team that gave the building its second rapid assessment, which was supposed to be more thorough than the first.
Graeme Calvert continued evidence from building inspectors who assessed the CTV building in the days after the September 2010 quake.
Calvert, at the time a senior building support officer for the Christchurch City Council, filled out the CTV building level 2 green placard, which meant there was no compulsion on the owner to get a detailed engineer's assessment before the building could be occupied.
Calvert arrived at the CTV building about 11.45am on September 7, along with two other council staff. None was an engineer.
They had been asked to look at central-city buildings to determine whether there were any obvious dangers or hazards, then take remedial action to minimise hazards, such as making a barrier or marking out a dangerous area.
They were at the CTV building for up to an hour.
Calvert noticed the building had been given a green sticker from a level 1 rapid assessment two days earlier.
They went inside and spoke to the receptionist and another man, who appeared to be a "boss" of one of the businesses.
Calvert asked them if they had any concerns about the building or any issues his team should look at, but neither did.
He was told an engineer would inspect the building, but was not told when.
Calvert said this was "not ideal", but there was a "backup" that an engineer would perform the detailed assessment.They went to inspect inside the building, but could only get as high as the second or third level because the top floors were locked.
He noticed cosmetic damage but "no obvious damage that caused me any concern".
"The fact we could not see obvious things wrong with the building did not mean there were not things structurally wrong," he said.
"There could be cracks in the foundations or all sorts of things that were hidden from view."
The team concluded that there was no reason after the September 7 inspection for any alarm with the CTV building, he said.
Calvert filled out a level 2 assessment form on the CTV building, marking it as G2, meaning it could be occupied but repairs were required.
On questioning, he said knew a green placard did not compel a building owner to carry out an engineer's inspection, but he had been told this would be done, and he expected that the council would contact the owner to ensure it had been done.
He had no recollection of a gap found in the floor on one of the levels.
"If there was something obvious I would have noted it and I would have raised it with the building manager and receptionist," he said.
"I would have gone in there and told them to get out."
The team did not alert people at emergency headquarters that the CTV building needed an engineer's assessment.
After the February 2011 quake, Calvert was again involved in rapid assessments, but teams were not allowed to do assessments on buildings without an engineer and someone from Urban Search and Rescue.
Quick CTV inspection
A city council building inspector who gave the CTV building a green placard after the September 2010 quake said his team did only a quick walk around the building and did not notice any obvious damage or hazards.
Peter van der Zee was the first to read his statement to the royal commission this morning.
He was declined a request to not be filmed while he gave evidence.
"It's not as if he's been personally traumatised by being in the building on the day," Justice Mark Cooper said.
Van der Zee, along with a structural engineer and someone from Urban Search and Rescue, gave the CTV building a rapid assessment on September 5, 2010.
The team assessed several central-city buildings that day.
The CTV assessment was external and concerned only level 1 of the building.
He filled out most of the level 1 assessment form in the car park after walking around the building. The team did not go inside.
"We had not seen any obvious damage or hazards to the exterior of the building," he said.
After discussion between members of the assessment team, they agreed it should be given a green placard.
Counsel Mark Zarifeh questioned van der Zee about training and his understanding of the assessment process.
He had listened only to a briefing at the Christchurch Art Gallery, which became the emergency operations centre after the quake.
Van der Zee believed this was normal among most people carrying out the rapid assessments, and he believed the briefings were sufficient.
"We were looking for obvious damage or hazards," he said.
"We probably weren't thinking too much further down the track."
Van der Zee did not know whether there would be any follow-up.''
He had believed level 2 would be inspected if there were potential issues identified on level 1.
Richard Sullivan, a structural engineer, was on the assessment team with van der Zee.
In his evidence read out to the court, Sullivan said he had little recollection of the CTV assessment but he did take photos.
Sullivan recalled only that they looked at the east and south walls but did not note any damage.
CTV assessments studied
One hundred and fifteen people died in the CTV building's collapse and subsequent fire during the February 22, 2011, earthquake.
Four men, Peter van der Zee, Graeme Calvert, Russell Simson and Dave Flewellen, are due to give evidence about rapid damage assessments they did after the September 4, 2010, quake.
The commission has already heard witnesses who worked in or visited the building before the disaster describe the post-September damage.
More than 80 witnesses are being called during hearing, which covers the initial building consent issued by the Christchurch City Council, the construction and design, identification of a structural weakness in 1990, and the assessment after Boxing Day quakes in 2010.
The commission has until November 12 to complete its work.