Displaced Opal Tower residents have return date delayed again

In a letter from the construction company responsible for the building, residents were told their temporary accommodation and food allowances had now been extended to February 16.

Owners and tenants of Sydney's cracked Opal Tower who are still living in temporary accommodation have had their return date delayed yet again.

A third group of residents who were due to move back in from Saturday have been told their temporary accommodation and food allowances have now been extended until Saturday, February 16.

Two groups of residents have moved back into about 170 apartments since late January.

Some residents of Opal Tower have had their return date delayed again. Source: AAP

"The engineers are continuing to work through their respective queries to enable the progressive re-occupation of apartments," Icon, the construction company responsible for the building, said in a letter to residents on Friday.

"As there are various parties involved it is important that all queries are satisfied."

The 36-storey high rise was evacuated on Christmas Eve last year, after cracks appeared in the walls.

Design engineers WSP maintain the building is structurally sound overall, a verdict also made by the state government's independent engineering experts.

Some 74 apartments were deemed fit for reoccupation by the body corporate's engineers Cardno in late January, while another 97 passed the test in early February.

In the interim report released earlier this month, investigators found that several factors could have contributed to the building's problems, but ruled out weather and dodgy materials.

Two groups of residents have already returned to their homes. Source: SBS

"While we have isolated the probable cause to localised structural design and construction issues, we need more information to make definitive conclusions about the cause or causes of the damage," the report's authors said.

"More work is also needed before we can provide recommendations on what needs to happen to avoid incidents like this in the future."

Icon expects Cardno will release a third list of safe-to-occupy apartments within the next week.

Some of the residents of the units cleared for return have refused to move back because they say the building is still a "construction zone".

Icon announced last week, however, that it would no longer pay for food and accommodation for the residents of 97 apartments after Cardno declared them safe to occupy.

Earlier this month, a group of residents who own apartments in the building sent a letter to the Prime Minister, NSW Premier and State Planning Minister detailing the "pain, loss and deceit" they have experienced through the ordeal. They called on the state government to ensure those behind the "crisis" take responsibility.