An apartment owner in the cracked Mascot Towers building has broken down while giving evidence to an inquiry into NSW building standards, saying owners "should not be accountable" for structural faults.

Key points: The inquiry was set up after a series of faults emerged in buildings across Sydney

The inquiry was set up after a series of faults emerged in buildings across Sydney Minister for Better Regulation Kevin Anderson has been criticised for not attending

Minister for Better Regulation Kevin Anderson has been criticised for not attending The inquiry heard only 30 per cent of the state's high-risk certifiers will be audited

The inquiry, set up last month after major faults appeared in residential buildings such as Mascot Towers and Opal Tower, is investigating the regulation of building standards, building quality and building disputes.

In the first day of evidence at the inquiry, Vijay Vital, a resident in Mascot Towers — which was evacuated in June — told the committee of NSW MPs of his dismay that owners were recently handed a $10 million repair bill "which I am pretty sure not all of us can pay".

Mr Vital, who has lived in the building for a decade, said it was unfair that owners now had to foot the bill for cracks that emerged in their building through no fault of their own.

"Similar to any Aussie family we have been paying all our taxes, rates and all due payment," he said.

"We have insurance but we cannot claim on it until we know a root cause [of the fault].

"I stand here as a parent as well, my daughter keeps asking when we can go home.

"I have done things that are right, we should not be accountable for it."

A crack in the Mascot Towers building, which has been empty since June. ( AAP: Bianca De Marchi )

Residents at the 132-unit Mascot Towers are still living in temporary accommodation as repair work is carried out on the 10-storey building.

Last week the ABC revealed residents are facing a multi-million-dollar bill to fix the building, and will vote on several proposals — including to employ a lawyer — later this month.

Alton Chen, who also owns an apartment in the Mascot Towers building, told the inquiry before purchasing in the building, he read through the property's records and "nothing really flagged" as an issue.

The pair called for intervention above the rental assistance residents are receiving from the State Government.

Mascot Towers resident Alton Chen said he did due diligence before purchasing the unit. ( ABC News )

"There is a lot of uncertainty ahead of us," Mr Chen said.

Earlier in the inquiry, NSW Fair Trading Customer Service representative, Peter Dunphy, said an audit commissioned in the wake of the Opal Towers fiasco was underway.

He said the Government was due to meet the target to review 25-30 per cent of high-risk certification work audited annually.

NSW Minister for Better Regulation Kevin Anderson has faced criticism from some sectors, including committee chairman and Greens MP David Shoebridge, for his failure to attend.

A spokesperson for Mr Anderson said it was standard for a minister not to appear at such inquiries.