Some residents of the cracked Opal Tower in Sydney could be back in their homes as early as Saturday after engineers declared the building safe for occupation once stabilisation works are complete.

The newly-built tower in Sydney Olympic Park was evacuated on Christmas Eve after cracks found in the building sparked fears it would collapse.

In a letter sent to residents on Thursday, the tower’s builder Icon said design engineer WSP and a third party engineer had confirmed the building is safe for reoccupation following the completion of stabilising works which are due to finish on Friday.

While apartments requiring no work will be safe to occupy from Saturday, other apartments needing minor works will not be ready for another week and those requiring remedial work will not be ready for between four and six weeks, the letter says.

Icon added the caveat that it was still waiting on advice from Cardno, the body corporate’s engineer, regarding the relocation of residents back to the building.

Some residents have expressed concerns the building is not safe, despite Icon’s assurances.

“Of course it’s not safe since we haven’t received any clearance from the government,” one resident told AAP on Friday.

It comes ahead of an expert report on the tower being handed to the state government.

Engineering experts Mark Hoffman and John Carter, who have been commissioned by the state government to conduct an independent investigation, are expected to address rectification plans and the safety of the building.

AAP understands Planning Minister Anthony Roberts’ office could receive the report late on Friday.

Last week the pair said they’d found no evidence of issues with the foundations of the building.

Some residents have spent every night since in temporary accommodation awaiting the all clear.

Developer Ecove, which has previously said the building is high quality, said on Wednesday remediation work could take weeks.

Icon last week defended gutting some apartments in order to allow equipment to prop up the concrete slabs separating each floor.