Opal Tower declared defect-free eight years after evacuations

A ribbon-cutting ceremony has taken place at the once-plagued Opal Tower in Sydney's west to mark the building officially being declared defect-free.

The celebration brings an end to a saga, spanning close to eight years, that involved a class action, two legal cases, ongoing rectification work and relocations after cracks appeared on level 10 of the complex on Christmas Eve in 2018.

Fearing a collapse, thousands of people were forced to evacuate with the emergency response also shutting down the nearby train station and surrounding roads at Sydney Olympic Park.

At the time, police said the tower had moved "1 to 2 millimetres".

Days later, more cracks were discovered on other levels of the 36-storey high-rise.

Opal Tower Owners Corporation chairman Shady Eskander has been at the forefront of the fight to get the complex repaired and secure compensation for those affected.

"It's fantastic to announce that Opal Tower is defect-free."

Mr Eskander told the ABC that a lot of work had taken place and millions of dollars had been spent to be able to declare "this building is the safest and best residential building in Australia".

"Everything that was done was done with the consultants, with the builder, with all of those involved in the design and construction of Opal Tower.

"We came alongside each other in a very collaborative manner."

Developer Ecove, backed by Japanese firm Kajina Corporation, engineers WSP, and builder Icon have been the other parties involved in the process.

20-year structural warranty

An engineer's report commissioned by the NSW government concluded in 2019 that the cracks had been caused by a combination of "design and construction matters, in particular changes made after the original design".

In what Mr Eskander described as an Australian-first, the high-rise is now protected by a 20-year structural warranty.

All owners have been fairly compensated, and all legal matters have been resolved.

"This is the greatest property comeback story in Australian history," Mr Eskander said in a statement.

Nutan Borkar was out of her unit for 11 months after the incident, and was glad there was finally "light at the end of the tunnel after a big struggle".

"It's great because a lot of time has been invested in getting the building back to the way it should've been," she said.

"I love being here. I wouldn't think of being anywhere else but here now. It's home."

Building standards were lifted across the state, with the Coalition government at the time introducing the role of building commissioner and a suite of other reforms.

"The lesson that can be learnt from Opal Tower … is that quality needs to be there so that defects aren't," Mr Eskander said.

"And we need to ensure that defects don't occur in the towers that are being constructed over Sydney because builders and contractors will spend more on fixing the defect than building it right the first time."