The nightmare has returned for residents of Sydney's troubled Mascot Towers, with fresh concerns about cracks in brick work at the troubled apartment complex.

Fire and Rescue NSW was called to the 132-apartment complex late on Thursday after reports of cracking in the brickwork on a facade of one of the apartment towers. The area was taped off, with temporary fencing to go up on Friday.

A Mascot Towers spokesman said on Friday the cracking, which had been inspected by engineers, was cosmetic and did not affect the building's structural integrity.

Nonetheless, some commercial tenants had been asked to temporarily vacate the complex and a public safety zone had been set up as a precaution.

"No bricks have fallen, there have been no incidents and the risk of falling bricks is deemed small by our professional engineers, but we have a duty of care to the public and we have acted to ensure public safety," the spokesman said on Friday.

"We are developing a remediation plan to address this issue and we hope to have that plan finalised within a week to allow remediation to get underway."

Shops evacuated after fresh cracks found at Mascot Towers_1
Tearful Mascot Towers homeowner Vijay Vital at an August inquiry into the cracking. Photo: AAP

Residents of Mascot Tower's 132 apartments were evacuated in mid-June due to cracking in the primary support structure and facade masonry.

In late August, owners agreed to raise a special $7 million levy to pay for the first stage of rectification works. The total repair bill was expected to top $10 million.

Some residents also remain barred from the complex, with the NSW government extending rental assistance until March 2020.

The Mascot Towers evacuation – and a spate of others across Sydney, including Opal Tower at Sydney Olympic Park – prompted the appointment of NSW's inaugural building commissioner.

NSW Better Regulation Minister Kevin Anderson said on Thursday that the commissioner, David Chandler, would have up to 15 staff to introduce reforms to the state's troubled building sector.

The changes – including a star rating system to identify and ban high-risk builders with bad track records – are part of the contentious NSW Design and Building Practitioners Bill. It is expected to be on the agenda when NSW Parliament resumes next week.

Mr Anderson said the legislation needed to be passed.

"We want our team ready to go, to deliver the project as soon as possible after that," he said.

"We are also making progress on the risk-ratings tool, which aggregates builder, designer, certifier and developer data to create a risk and compliance profile for each project."

-with AAP