Engineers have warned that a major fire in a high-rise Sydney apartment is inevitable because "the building system in New South Wales has broken down".

The warning came in a report compiled by the Engineers Australia Multi-disciplinary Committee that will be released publicly on Wednesday.

Some of the report's key findings were that New South Wales had Australia's worst building certification system and 85 per cent of strata units were defective on completion.

The report also found that New South Wales insurance companies reported repair costs of an additional 27 per cent.

One of the report's authors, engineer Robert Hart, said the situation was only going to get worse.

"There are something like 20,000 new units coming on stream over the next few years, and we know they are being done by developers who are totally inexperienced and [have] no real interest in anything other than making money and this is causing major concerns," Mr Hart said.

"There is a raft of issues. It is occurring daily but no-one is inspecting this stuff.

"This is what is going to cause a major incident at some point.

"There are some very clever fire engineers in this city and they have the most appalling stories."

Mr Hart described the major problems as:

Fire separation between apartments;

Fire separation between apartments; Almost no fire gaps installed correctly;

Almost no fire gaps installed correctly; Fire dampers that prevent the spread of smoke are very seldom installed correctly;

Fire dampers that prevent the spread of smoke are very seldom installed correctly; Electrical installations not properly done.

Consulting engineer Charles Rickard said the major conclusion from the report was that the building system in New South Wales had "broken down".

"The system needs to be tightened. Everyone is focusing on price not on quality. Training is falling by the wayside," Mr Rickard said.

The report recommended the creation of new governance bodies drawn from every discipline in the industry including architecture, civil construction engineering, electrical engineering, mechanical engineering, fire and acoustics.

Mr Rickard said those who made up the new bodies should be asked to come up with a prescriptive system for every part of the industry.

The Master Builders Association agreed there were pockets of the industry that had problems.

But MBA executive director Brian Seidler said architects also made mistakes and clients made requests that did not comply with all building codes.

"Australia is being inundated with non-conforming products from countries where they don't have any standards yet clients specify that they be put in place," he said.