The New South Wales Building Commissioner says he is appalled by "third world" and "nightmare" conditions at two Newcastle build sites.

Commissioner David Chandler, along with SafeWork NSW and NSW Fair Trading inspectors, attended five construction sites in Newcastle on Thursday. 

They said they identified potential construction-related building concerns at two sites, including at 106 Brunker Road in Adamstown, which Mr Chandler described as a site with substantial flaws.

"The status of safety on the job was evident. It was non-existent," he said.

"It was just an absolutely appalling nightmare both from a safety point of view and from a building compliance point of view."

NSW SafeWork Inspectors have an existing prohibition notice on the site in relation to unsafe scaffolding and working in proximity to powerlines.

The commissioner said he expected SafeWork NSW to issue a stop-work order later today or tomorrow.

A spokesperson for the development and builder Metbuilt says "significant efforts are being made to ensure the site complies with all safety codes".

A 'wreck of a site'

Mr Chandler raised fears about a second site in Watt Street in inner-city Newcastle.

The Watt Street site is owned by developer, Keith Stronach, who the commissioner said recently sacked the builder.

It has a prohibition notice on it and Mr Chandler said a stop-work notice would be issued this week.

"It wasn't as bad as Brunker but it wasn't far behind," he said.

"Now, that's third world electrical wiring.

"It's just unbelievable and I couldn't get to the basement in that building because it was such a wreck of a site in terms of blockages and rubbish."

The ABC has contacted Mr Stronach for comment.