A Sydney apartment complex remains "wholly evacuated" due to ongoing and persistent cracking with about half of tenants offered the possibility of an escorted trip back inside to collect some personal belongings.
Mascot Towers was vacated on Friday night after engineers became increasingly concerned about cracks in the primary support structure and facade masonry of the decade-old building in the inner-south suburb of Mascot.
Residents were told to be ready to leave at short notice and a temporary structural support was urgently installed on Thursday after building management noticed the cracks were widening.
The consulting engineer has since determined three access zones to be in place for the next five to seven days, according to an update provided to owners and occupiers and seen by AAP on Sunday.
"Thereafter the engineer will advise if further monitoring or alternate and corrective action is required."
Sixty-four of the 122 units are in the partly-accessible zone and tenants have been told they "may be accessed for a short period of time to collect personal effects only with escort by the building manager" by appointment from Monday.
All of the other units fall in the non-accessible zone and cannot be entered at any time, along with car parks and recreational areas including a Thai restaurant, IGA Express and a cafe.
Residents need to seek alternate accommodation and have been provided with prompts to Fair Trading NSW - including entitlements for strata owners and renters - and for those experiencing financial hardship as a result.
Daily updates will be provided via email with a meeting of the owners likely to be held mid to late in the week.
NSW Premier Gladys Berejiklian says the government wants to "get to the root cause" of what has occurred.
"There was some speculation it could have been from things that happened in the near vicinity but we need to find out the cause before we know how to act," she told reporters on Sunday.
When asked if the state government would help displaced residents in the meantime, Ms Berejiklian replied: "We're getting to the bottom of what happened".
"The NSW government will hold everybody to account, that's our role," she said.
One tenant, now living with a friend, said he was effectively homeless after being given 75 minutes to leave.
While the cause of the cracks has not been determined, local MP and former mayor Ron Hoenig noted another apartment tower was recently built next door.
He'd been advised there was no chance Mascot Towers would collapse.
Transport for NSW says the airport rail line and Mascot train station, underneath the complex, are not impacted.
In December, the Opal Tower apartment complex in Sydney Olympic Park was completely evacuated due to cracking and reports of movement.
Engineers Australia said the situation was further evidence reform is needed in the building and construction sector.
"It is time to finally implement the changes agreed by Council of Australian Governments in response to its inquiry into regulation of the sector," spokesman Jonathan Russell said in a statement.
The premier said strata building policy is "always a work in progress" and "of course" more needs to be done
"We need to ensure their rights are protected, whether they're owners or whether they're tenants," she said.
Ms Berejiklian said she anticipated the new Building Commissioner would be named in the "very near future".
Mascot Towers' building manager declined to comment when contacted by AAP on Sunday.