SkyCity Convention Centre demolition begins in Auckland

Three months on from the SkyCity Convention Centre fire, demolition workers are now beginning the painstaking task of partially demolishing the $700 million build.

On Wednesday, the first loads of scorched debris were removed from its roof - but there's still yet to be a timeline for its rebuild.

Workers were lifted by crane onto the blackened roof to collect debris. Even elements that visibly appear uncompromised, like steel support beams, may need to be removed.

"Would you guarantee that for the 25, 40-year lifecycle, whatever it may be, given the fact it's just been subject to 500C heat and you can't see any damage on it?" AUT University head of Built Environment, Professor John Tookey, asked Newshub. 

What's removed also needs to be recycled. There's the potential for mould damage, after millions of litres of water was pumped into the building to extinguish the fire.

"During summer time the mould is going to grow faster, especially where you've got hot humid conditions, it's going to take off quickly," Massey University director of Built Environment Research Robyn Phipps said.

Fletchers Construction has filmed the damage but has refused to release the footage as of yet.

It's also yet to confirm the cause of the fire, saying it will still be "some weeks before a full timeline for the rebuild is completed" - although it's committed to opening it "quickly".

However, the extent of the damage indicates a "quick" opening is unlikely. APEC Leaders' Week in November next year may need to be moved to a different venue.

"APEC NZ is progressing contingency plans... These involve discussions with multiple venues and are commercial-in-confidence," said Andrea Smith, deputy secretary of APEC 21 at the Ministry of Foreign Affairs and Trade. 

Other events booked for the convention centre are considering moving to Christchurch or to a different country entirely.

Both professors say this demolition might be the most complex ever undertaken in New Zealand.

"Within the New Zealand context, I struggle to think of anything that's ever been like that," Professor Tookey said. 

Which is why it may be years yet until this convention centre is finally open.