Residents of a 132-unit apartment complex in Sydney were given just two hours to grab their belongings and leave their homes last month.

The evacuation was prompted by the discovery of large cracks in the building's support structure. Engineers later reported that the building also appeared to be moving. The residents have yet to return.

The incident prompted widespread alarm because it was the third evacuation of a defective apartment building in Sydney in less than a year.

Last December, the residents of a 392-apartment complex were evacuated after the discovery of cracks in the concrete.

And it emerged last month that an inner-city set of apartments had been evacuated due to water damage and fears of a fire risk. The units have remained empty for more than eight months.

The evacuations have led to growing calls to improve building quality and safety standards.

Sydney is in the midst of an apartment construction boom, but concerns about safety are reportedly leading to some home buyers giving new buildings a miss.

Federal and state ministers held an emergency meeting on Thursday to address problems in the industry.

Federal Industry Minister Karen Andrews said the ministers had agreed to adopt a "nationally consistent approach" to building safety standards.

"Consumers... and members of the building and construction sector can rest assured their state and territory governments are committed to resolve the issues that have plagued the sector for many, many years," she said yesterday.

In Sydney, the number of apartments is soaring, with construction last year of 30,880 apartment buildings, townhouses and terraces. This has led to hefty drops in rents in some areas and a near-doubling of the city's vacancy rate in the past two years to 3.2 per cent.

According to a report in The Sun Herald, 32,680 units were listed for rent on the Domain property website last month, compared with 17,500 listings in June 2017.

Mr Phil Gall, chairman of the Owners Corporation Network, an organisation that represents owners of apartments and other shared properties, said that the rush to build upwards has led to declining quality.

"The predicament facing ... apartment owners (in the two evacuated complexes) is only the visible tip of a very big iceberg," he wrote on the ABC News website last month.

"So my advice to my kids today, and anyone who'll listen, is this: Do not buy a new apartment, especially if it is over three storeys high."

Experts say there is inadequate oversight by the authorities to enforce standards of both materials and workmanship.

There are also concerns about the use of flammable cladding in buildings across Australia - a problem that gained global exposure following a tragic fire at London's Grenfell Tower that killed 72 people in 2017.

On Tuesday, Victoria's state government announced a A$600 million (S$575 million) plan to rectify cladding in 500 buildings deemed at high or extreme risk.

In New South Wales, the most populous state, 629 buildings have been identified as being at risk. There is no plan yet to resolve the problem.

Although states have rules to prevent the use of flammable materials in buildings, there are concerns that they are not being enforced and that there is a lack of independent oversight to protect against "cowboy" builders.

NSW Premier Gladys Berejiklian is planning to overhaul the state's building safety regime, and this includes appointing a building commissioner to oversee the industry. She is also expected to make it easier for property owners to get compensation from negligent builders.

"We know there's a problem," she told The Sydney Morning Herald last week. "We allowed the industry to self-regulate and it hasn't worked. There are too many challenges, too many problems, and that's why the government's willing to legislate."

NSW's Parliament this month launched an inquiry into the state's building standards and disputes. The committee's chair, Greens MP David Shoebridge, said the recent evacuations had left residents homeless and meant owners faced large costs for repairs as well as a decrease in their home values.

"With an increase of high-rise apartments, particularly in the Sydney region, it is extremely important that the NSW government has adequate regulation and oversight of the building industry, including appropriate consumer protection," he said.