Watch: Bird's-eye view shows progress at NZ International Convention Centre

Plans show the convention centre and its lane way from Hobson to Nelson St.

Development of the $703 million NZ International Convention Centre is well underway.

The project, commissioned by SkyCity Entertainment Group, has used the equivalent of 12 Sky Towers of concrete and structural steel.

"That's more than 7300 tonnes of structural steel, a further 330 tonnes of secondary steel, more than 173,000m3 of concrete, and 17,000 litres of paint," SkyCity said.

Drone footage, provided by architects Warren and Mahoney, takes viewers into the heart of the construction, hovering above the new five-star Horizon Hotel behind TVNZ, through the new laneway between Hobson St and Nelson St and panning down the sides of the new building.

Platforms for seating in the theatre are now built, showing the size of that space, able to seat 2850 people and set to be New Zealand's largest theatre.

The lifts have the second largest design capacity in the world, rated to carry up to for 11.2 tonnes each and objects up to 3m long, SkyCity said.

More than 20 conferences have been confirmed and there are more than 250 in the conference, meeting or convention sales pipeline.

The project by Fletcher Construction is on a 1.4ha site, will be 32,500sqm of floor space or the equivalent of 3.2ha of indoor floorspace, five times larger than the existing New Zealand convention areas.

The property will be able to host conferences and one-off events for up to 4000 people and will have New Zealand's largest theatre.

At the new five-star Horizon Hotel, electrical, plumbing, communication, security and air conditioning work is underway from the basement through to the sixth level.

The concrete floors are poured up to the top or level 12 of the hotel and steel works are being installed for the roof.

Yet, when Fletcher won the contract in October 2015, construction was predicted to start in late December that year, run for 38 months and that would give it a potential finish date in February next year.

SkyCity is withholding $26.9 million from the Fletcher Construction Company because of issues.

In notes to the annual accounts contained in the annual report released to the NZX, SkyCity reveals that the $26.9m is liquidated damages and kept "as it considers that it has the right to these funds under the liquidated damages provisions in the construction contract with FCC."

Fletcher has notified SkyCity "that they dispute SkyCity's right to these liquidated damages," the accounts say.

The money was due to be paid to Fletcher under the progress claim as the NZICC rises but issues with the job resulted in SkyCity penalising its builder.

The centre is not now due to open until next December.