Craig Fitch's apartment building is so highly flammable that residents were ordered to remove wood-chip mulch and trees because of fears any fire in the garden could quickly engulf the block.

Key points: Residents of dodgy apartments hope the cladding scheme will lead to other problems getting fixed

Residents of dodgy apartments hope the cladding scheme will lead to other problems getting fixed Craig Fitch lives in a complex covered in combustible cladding, which is also falling apart

Craig Fitch lives in a complex covered in combustible cladding, which is also falling apart Engineers warn removing the dangerous cladding will expose other building faults

"It's extremely dangerous," Mr Fitch said.

Large parts of the complex, located in Frankston in Melbourne's south-east, is wrapped in non-compliant polystyrene, painted to look like concrete.

The highly combustible material is even surrounding the emergency exits for multiple apartments.

"Apparently it goes up like petrol," Mr Fitch said.

"In a case of a fire, how would [residents] get to the street?"

Last year the Victorian Building Taskforce issued an emergency order on the building, initially instructing residents to fix the combustible cladding within seven days.

It was an impossible demand and one that infuriated residents who had, for years, been flagging concerns with the Victorian Building Authority (VBA) about a range of issues.

The builder has since been deregistered.

"There's mushrooms growing in the building, there's leaking windows and doors," Mr Finch said.

"We're on our third balcony collapse."

Apartment owners say this Frankston complex needs more than new cladding. ( ABC News: James Oaten )

The property is one of 15 buildings to undergo emergency rectification works as part of the Victorian Government's plan to fix 500 buildings considered to have the highest risk of fire.

But it remains unclear how far rectification works will extend beyond replacing the combustible cladding.

"We want the place brought up to code," Mr Finch said.

"I don't care what that means. They've let us down in such a bad way if they find stuff under there that needs to be fixed, it needs to be fixed. They just can't just patch work the problem."

'Never seen a compliant building'

The State Government has earmarked a budget of $600 million to fix the 500 most dangerous buildings over a five-year period.

Each building will be treated on a case-by-case basis, meaning the type of work necessary to make the building "safe" could widely differ depending on the apartment complex.

The Government fund may be used to replace cladding and fix faulty alarm systems, while other defect issues are referred to the Victorian Building Authority.

But engineers are concerned removing the cladding will expose a litany of fire safety problems.

"I have never seen a compliant building," engineer Jonathan Duler said.

"Whenever I look at a building, the problem that people think is there, is not the real problem."

Hundreds of buildings have been identified as having risky cladding across Victoria. ( ABC News: Michael Barnett )

Mr Duler, who works for a fire and forensic engineering firm, Basic Expert, said common problems include faulty fire detection, smoke ventilation and sprinkler systems, walls and plumbing not sealed properly, and unsafe fire exit and elevator systems.

"I would put aside about $3 billion," Mr Duler said.

"It's going to be the biggest and most expensive exercise we've experienced in decades.

"We've got a lot of buildings here. They haven't been done right since 1995, 1997.

"As time went on builders knew they could get away with things, so it's just been increasing since.

He said some buildings were beyond repair.

"I would like to see some buildings demolished," he said.

The state-wide audit is set to continue until 2023 and every week new high-risk buildings are identified.

The Victorian Treasurer, Tim Pallas, said the Government had the capacity to increase the rectification budget if needed.

"We do have a modest contingency capacity," Mr Pallas said.

"From my perspective, we will do whatever is necessary to protect the welfare of Victorians."