Demands for excessive deposits, unlicensed contracting and failures to comply with rectification orders were among the offences "continuing to plague the home building industry", said Fair Trading Commissioner Rod Stowe.

"While our investigators and complaint handling services can call dodgy builders to account, the best consumer defence is always thorough research. Check your builder's bona fides online before any contract is signed or any money changes hands."

NSW Fair Trading's quarterly enforcement report found the $421,583 netted from disciplinary action against 78 offenders of the Home Building Act 1989 from January to March was up from $275,244 in the previous quarter.

The state's biggest offenders were Steven Miller, aka Mustafa Malas, of Hurstville (fined $48,190 on January 5 and given a custodial sentence), Paul Logan of Guildford (fined $75,775 on  January 21) and Johnson Bazi of Prairiewood (fined $50,734 on February 2).

"Miller", who had previously ripped off residents in St George and the Sutherland Shire, was last year found to be falsely operating under the registered business name Ambient Landscapes Pty Ltd, a family-run landscaping company based at Somersby near Gosford.

The 2016 figures came just days after an unlicensed Sydney contractor who was handed a $500 penalty infringement notice paid more than four times the amount after he attempted to challenge the matter in court.

Charles Itaoui of Guildford was issued the infringement notice in February 2015 after he was found in breach of the Home Building Act for completing and accepting payment for unlicensed residential building work.

Mr Itaoui had contractor licences in electrical and air-conditioning but did not have a building licence.

Mr  Stowe said the finding had important implications for the home building industry.

"It's important from a consumer's point of view that the regulator can now take action when people are contracting to do work they are not qualified to do. From the regulator's point of view it provides certainty to action we've taken in the past, and continue to take," he said.

"I think that's the really important thing. We are effective as regulators in administrative law and that is what this determination has done."

Mr Stowe said that a 2015 NSW Civil and Administrative Tribunal (NCAT) decision, relied on in Mr Itaoui's defence, had allowed "a little uncertainty," about whether an unlicensed contractor could perform residential building work, if supervised by an endorsed licence holder.

That decision stated that if an unlicensed non-employee was supervised by an endorsed licence holder or supervisor that person could do residential building work.

But Mr Stowe said the judgment in Mr Itaoui's case made it clear the Home Building Act requires the holder of a contractor licence to "only contract with other licensed individuals".

"People can't hide behind the suggestion they are working with someone else to escape the provisions of legislation," he said.

"You need to be properly qualified  to do that work and while [Mr Itaoui] had a couple of other licenses they weren't the same as having a full building license to contract of this sort of work and it's for good reason that is the case.

"People have to have the right skills to be able to undertake that type of project, and that clearly wasn't the case here."

smh.com.au