Engineers have faced a legal grilling for declaring the Pyne Gould Corporation building "safe to occupy" despite knowing almost nothing about its low underlying strength.
Holmes Consulting Group engineers Mark Whiteside and Alistair Boys faced tough questions by lawyers at the Canterbury earthquakes royal commission yesterday, including whether they had fulfilled their "ethical obligations" to keep occupants of the PGC building safe.
The commission is conducting a hearing into the collapse of the five-storey building in which 18 people died in the February 22 quake.
The hearing, due to continue today, has been adjourned until Monday because one of the commissioners is ill.
After the September 2010 quake, Whiteside and Boys conducted four damage assessments of the PGC building, including one after the Boxing Day quake, all involving a brief visual inspection.
Based on these inspections, the men repeatedly advised that the building was "safe to occupy", despite concerns among some tenants about worsening cracks.
Whiteside yesterday said the inspections concentrated on whether the building had deteriorated after the September quake, not its overall strength. Initial visual inspections revealed no "diminished capacity", and a more detailed inspection was deemed unnecessary, he said.
"The building didn't have any diminished capacity, so the building was safe to occupy."
Commission lawyer Marcus Elliott, who represents victims' families, said claiming the building had not "diminished" without knowing the building's strength appeared a "bit meaningless". "You're not looking at whether a building's strength is good or bad; you're just saying it was no less good or bad than it was before," he said.
Whiteside and Boys admitted they were unaware of two reports by their own engineering firm, Holmes Consulting, which highlighted the PGC building's low resistance to quakes. One report, in 2007, said part of the building had a "severe weakness seismically".
The men were also not aware the building had been classified "potentially earthquake-prone" between 2005 and 2006, nor had they viewed the building's plans.
Elliott questioned how it was possible to declare the building safe without checking its history. "You didn't have enough information to say it was safe to occupy."