The NSW government is being warned it could face a multibillion-dollar lawsuit from apartment owners if it doesn’t urgently address the state’s building problems.

The peak body representing strata residents and owners will meet government representatives on Wednesday to demand they fix the “dog’s breakfast” in construction standards and flammable cladding.

It comes after owners of units in Sydney’s beleaguered Opal Tower lodged a class-action lawsuit against the Sydney Olympic Park Authority, which owns the land on which the complex was built.

It’s unclear how many owners are involved, but the action – filed in the NSW Supreme Court on Friday – is being led by owner Terry Williamson.

The newly-built block in Sydney Olympic Park was evacuated on Christmas Eve after cracks discovered in the building sparked fears it could collapse. The claim from the lawsuit is expected to run into multiple millions of dollars.

Strata Community Association NSW president Chris Duggan said the Opal Towers action could “open the legal floodgates” unless the problems are resolved.

Mr Duggan will present a seven-point plan to Better Regulation Minister Kevin Anderson and is calling on the state government to legally require  builders responsible for the issues pay compensation.

He is also urging the government to match Victoria’s $600 million flammable cladding remediation plan as a response similar concerns about safety in that state.

The NSW government has already put the handbrakes on calls for a $1 billion funding package to help owners replace flammable cladding on properties across the state, while the federal government has refused to get involved.

As of July this year, 629 buildings were identified in NSW that could have cladding that poses a risk.

“The NSW government has reaped billions of dollars from the state property market in taxes and charges and it is time to put something back,” Mr Duggan said on Tuesday.

“If no solution can be found, I believe NSW will face potentially the largest class action the state has ever seen. Thousands of people in NSW have been caught up in this mess through no fault of their own.”

Premier Gladys Berejiklian was not fully aware of the lawsuit when asked early on Tuesday, but defended owners’ rights to take action.

“I don’t blame anybody for taking legal action to defend their own rights,” she said.

“This is an unfortunate set of circumstances. We inherited the system we have today and we’re aiming to fix it by the end of the year through legislation.”

Ms Berejiklian said the government would announce a new building commissioner “imminently” to oversee the problem-plagued construction industry.

“[The commissioner] will ensure moving forward that everybody in the industry not only is aware of their responsibilities, but delivers on those responsibilities to the nth degree,” she said.

In an update to residents in mid-July, the tower’s builder, Icon, said site works had been “progressing well” and structural work should be completed by the end of the month.

Residents of 40 apartments in Opal Tower expect to be allowed to return to their units on Friday after inspections are carried out.

The body corporate’s engineers, Cardno and BT Project Management, are at the site regularly to inspect the structural work.