The NSW government has vowed to crackdown on dodgy building certifiers as it cops pressure in the wake of Sydney's cracked Opal Tower saga.

The Berejiklian government has been under pressure to act after the Sydney Olympic Park apartment building experienced a concrete panel collapse on Christmas Eve which triggered the evacuation of the tower and the surrounding areas.

In the first state government press conference on the issue since the building's problems emerged, Minister for Better Regulation Matt Kean announced a crackdown on "cowboy" certifiers across NSW to address public concern about the state's building certification process.

Under the new strategy, 30 per cent of the industry will be audited every year and corrupt certifiers or ones who are negligently signing off on unsafe buildings will be kicked out of the industry.

Any certifiers who have breached the code of conduct in the previous 12 months will also be unable to work on new strata developments.

"Developers doing the wrong thing should be on notice - if they're working with their certifier mates to push shabby buildings through then we will rub them out of the industry," Mr Kean told reporters on Sunday.

A name and shame register will also be made public so people can check their building's certifier and the quality of their work.

Mr Kean also blamed previous Labor governments for allowing "cowboys" and "shonks" to operate by privatising building certification.

"The mess that's been created was done by Labor, (current state opposition leader) Michael Daley was part of the government that privatised certifiers in NSW, and allowed cowboys and shonks to operate in this industry," he said.

NSW Planning Minister Anthony Roberts says he's told the developer and the builder to spare no expense in looking after the welfare of the Opal Tower residents.

He criticised the opposition for creating "more anxiety" for residents by holding press conferences out the front of the building.

"It's not helpful when you have the opposition turning up each day standing up in front of the building creating more anxiety for the residents who are anxious enough," Mr Roberts said alongside Mr Kean.

He said the government has called for an independent investigation, the results of which will be made public, to find out what happened and to ensure it doesn't happen again.

Most residents were allowed back into the building within 24 hours after the cracking was heard, but on Thursday they were told by the developers the entire tower would need to be emptied again so engineers' investigations could continue for at least 10 days.

On Saturday the developer said some residents would need to be moved from their temporary hotel accommodation over New Year's Eve as their rooms had been previously booked for the celebrations.

Three residents have refused to leave their homes with Mr Roberts insisting they aren't impacted by the building's problems.

The tower is now subject to an internal and governmental investigation.