Two engineers who prepared a critical report on the fatal collapse of the CTV building have told an inquiry they believe they had the skills to carry out the task.
The Canterbury Earthquakes Royal Commission is investigating why the building failed in the 6.3-magnitude quake on 22 February, killing 115 people.
The report by the Department of Building and Housing in February this year found that the central city building did not meet standards when built in 1986 - something the firm that designed it, Alan Reay Consultants, has previously rejected.
On Monday, the firm's lawyer Hugh Rennie questioned the report's authors Clark Hyland and Ashley Smith about whether they had the skills for the job.
Both replied 'Yes' and Mr Smith added there was also an expert panel to review their findings.
Mr Smith told the hearing that a number of scenarios could explain the collapse, and the most likely was the failure of the column at the building's east face.
He said the concrete in some columns was significantly weaker than expected and steel drag bars used to connect to the buiilding's core lacked toughness and ductility - the ability to take strain without breaking.
"The drag bars that were installed at levels four to six only lacked toughness and ductility and in my opinion could not be relied on to sustain the ultimate response of the structure."