A structural engineer has told a hearing it would be unusual for building plans to be sent for council approval without first being checked by the design firm - as happened with the CTV building.
The Canterbury Earthquakes Royal Commission is investigating why the office block collapsed in the February 2011 earthquake, killing 115 people.
The commission earlier heard that the engineer who prepared the design plans had not previously worked on a multi-storey building.
It was also told the plans were sent for council approvals without being checked over by anyone else at the design firm Alan Reay Consultants.
On Monday structural engineer Arthur O'Leary said in his experience that would be unusual.
He said while calculations would not necessarily be checked, a senior person would normally cast a critical eye over the drawings to ensure they were coherent.
The commission is hearing its eighth week of evidence about the Madras St building. This week's evidence will concentrate on the issue of code compliance for the six-storey office block built in 1986.
Columns 'did not comply with standards'
Earlier, Dr O'Leary told the commission that some of the columns in the building did not comply with requirements when it was built.
A report by the Department of Building and Housing has previously found it did not meet relevant standards when it was constructed.
Dr O'Leary said some columns did not comply with standards but there were considerable difficulties in determining the best practice within the building industry at any given time.
He said an experienced council engineer might have noted these issues.
But he said council officers did not carry out peer reviews and he did not accept that an officer should have identified the areas of non-compliance, given the time available for the review.
However, when pressed by commissioners, Dr O'Leary said that where the council was not able to do a detailed check, it should seek a design certificate from the engineer.