An emotional John Drew says he felt a "huge sense of responsibility" after 115 people died in the Canterbury Television building collapse.
The CTV building manager told the Canterbury earthquakes royal commission today that he had "complete faith" in the structural integrity of the building, but the action taken before the quake had weighed heavily on him.
"Since February 22  I have felt a huge sense of responsibility and I am forever questioning what might have been done differently," Drew said.
"I can honestly say that on each and every occasion that I spoke with tenants of the building and staff of the businesses located within the building I gave what I believed was an honest and fair assessment of the state of the building."
He offered his condolences to the victims' families at the completion of his evidence.
It was "significant" the building had been green-stickered after the September and Boxing Day quakes in 2010, Drew said.
He had spoken to a structural engineer, quantity surveyor, insurance assessor and contractors.
"My focus throughout this period was to carry out repairs to the building as soon as practicable. I never for a minute had any thought the building might be at risk from collapse," Drew said.
He earlier told the hearing he could not recall whether he was at an engineering assessment with city council staff after the September 2010 quake.
The commission is investigating why the CTV building failed in the February 2011 quake. The hearing is in its second week.
Drew told the commission he had relied on the Christchurch City Council green sticker when he informed tenants the CTV building was safe to occupy after the September and Boxing Day quakes in 2010.
He said he had not been present during council assessments, but when previous evidence from a council engineer was read to the commission stating the CTV building manager had shown him through the building and unlocked different floors, Drew said he "couldn't remember that event".
"I don't remember but it could have been me," he said.
Drew owned a medical practice that shifted into the CTV building weeks before the quake.
The Clinic occupied the fourth floor of the building and 19 staff members and patients died when it collapsed.
Second week begins
Up to nine witness accounts relating to CTV building assessments after the Boxing Day 2010 quake are expected to be heard.
The commission has until November 12 to complete its work.More than 80 witnesses will be called during the eight-week inquiry, which will cover 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 the September 4 and Boxing Day quakes in 2010.