The ACT government has "no clue" about the scale of problems across Canberra's apartment developments because it does not proactively audit or keep copies of key design documents, according to an industry expert.
In evidence to the Assembly's building quality inquiry on Wednesday, structural engineer Mal Wilson also claimed Access Canberra was "run by a bunch of administrators" whose teams lacked technical expertise and industry insight.
The government has disputed Mr Wilson's claims and backed in the capability of the regulator's staff.
The head of Campbell-based firm Advanced Structural Designs, Mr Wilson has inspected some of Canberra's most troubled-plagued buildings, including the Elara apartments.
Mr Wilson, who spoke on behalf of Engineers Australia, said the majority of structural defects could be traced back to poor-quality, inaccurate or incomplete designs and drawings, which builders relied on during construction.
He claimed that in breach of its legislative requirements, the government did not retain all drawings and plans for developments, which made it near impossible for consultants to identify the cause of a defect.
That meant the government "doesn't knowing anything" and was "so ignorant" about the scale and type of problems in buildings across Canberra, he said.
"We had a 16-storey building in Belconnen I went to recently, and they [the government] did not have a single structural drawing," Mr Wilson said.
"And then they had to go begging to the developer, who can sit there and say ... 'well, maybe I've lost them."
Mr Wilson said he had inspected drawings which were "ineligible" and "crazy".
But alarmingly, he said the bureaucrats responsible for rubber-stamping the documents did not have the expertise to recognise if they were sub-standard.
He said in one instance a bureaucrat had approved a drawing, despite not being able to see most of it because it was covered with a large rubber stamp.
"I showed this [drawing] to someone in the department ... and they looked at it for a minute and they said 'what's wrong with that?" he said.
'I'm like, well, it's completely covered by a stamp!"
Mr Wilson said the government needed to urgently introduce a licensing regime for engineers, hire more technical experts, and proactively audit design documents for apartment developments.
We are the laxest state or territory around at the moment as far as occupational licensing goes and we think it [licensing more trades] will go a long way to improving.Jason O'Mara
Asked by committee chair Jeremy Hanson if the government had been historically "absent" in auditing, Mr Wilson said: "Absolutely".
"The government has no clue what is going on," he said.
An ACT government spokesman said from next week, certifiers would be required to adhere to stricter rules when submitting design documents for apartment developments.
The spokesman said "targeted audits" would be conducted as part of the new regime.
He said the government kept copies of all building approval documents submitted to it by certifers.
In response to Mr Wilson's comments about Access Canberra, the spokesman said it valued "the diverse skills, knowledge and experiences of the staff that are involved in the regulation of those that are licensed in the construction industry".
"On the issue of technical skills, Access Canberra's staff have a variety of technical experiences and qualifications in the areas of building, building surveying, architecture, electrical, plumbing and gas," the spokesman said.
A licensing scheme for engineers was being considered as part of the government's wider building regulation reform package, he said.
The penultimate public hearing at the Assembly inquiry also heard evidence from senior figures at the ACT branch of the Construction, Forestry, Mining and Energy union.
The union's branch secretary, Jason O'Mara, said the government needed to introduce licensing requirements for more contruction trades.
"We are the laxest state or territory around at the moment as far as occupational licensing goes and we think it [licensing more trades] will go a long way to improving," Mr O'Mara said.
"The people with the most skin in the game, the people that have control, whether than be contractual or economic control ... should also be held to account or have some sort of obligations and expectations placed on them," union official Zach Smith told the hearing.
Representatives from the ACT government are due to give evidence at the inquiry's final public next Wednesday.