The man who designed the CTV building took the job despite a lack of experience because he thought it would help him get a promotion, the Canterbury Earthquakes Royal Commission has been told.
The commission is looking at why the building in central Christchurch collapsed in the February 2011 earthquake, killing 115 people
The claim was made in closing submissions by the lawyer assisting the commission Stephen Mills, QC, who said the main reason the building collapsed was because of the incompetence of its designer, structural engineer David Harding.
Mr Mills told the hearing on Wednesday that being made an associate depended on how well Mr Harding performed at designing multi-storey buildings.
Mr Mills said Mr Harding was so far out of his depth he even neglected to do basic calculations and struggled to get a handle on software required to complete the design.
Despite this, he said David Harding retained confidence in his own ability to do the job and in giving evidence seemed to celebrate the fact he was teaching himself how to design office blocks while working on the CTV building.
Mr Mills said his employer, Allan Reay, was also responsible because he gave Mr Harding sole responsibility for the design.
The inquiry was told the Christchurch City Council was also to blame for signing off the plans for the building - despite the fact it failed to comply with the building code and its own by-law.
In giving evidence earlier, Dr Reay said he spent only a few hours looking at the building, while Mr Harding accepted that he was working beyond his level of competence, but was confident he could carry out the work.
Outside the hearing, Maan Alkaisi, whose wife was killed, wants lessons to be learned from the mistakes made in the design.
Mr Alkaisi said the closing submission was hard to listen to and it is unbelievable the lives of so many people were lost because somebody so inexperienced was given the job of designing it.
The building's defects should have been picked up by the council, he said.
The commission began hearing submissions in June this year and will finish this week.