The former NRC building at Whangarei Town Basin will have to be deconstructed to build the $20.97 million Hundertwasser Arts Centre with Wairau Maori Art Gallery.
The revelation comes as the project is about to go out for tender, with a Registration of Interest (ROI) documentation lodged on nationwide tender platform GETS on Friday.
The high cost of earthquake-proofing the building is partly behind the need to remove it, but the project's backers say most of the material removed will be recycled, in keeping with Hundertwasser's philosophy.
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Whangarei Mayor Sheryl Mai said the council was behind a 'careful deconstruction' of the building and reusing much of it for the arts centre.
"It's much better than just getting the wrecking ball through it. It's honouring the original masons who put it together without any reinforcing," she said.
"There will be no additional costs to the project in doing this process. Rather than having to work around a dodgy old building they can start afresh."
Ms Mai said one of the conditions of the lease to project backers Whangarei Art Museum and Prosper Northland Trust was that when it went out for tender they had to satisfy the council that they could pay for the job before any work starts.
The final project design includes considerable changes to both the foundations and the structure of the building, for the purposes of seismic strengthening. The finished art centre will be substantially heavier than other buildings of similar size, due to the extensive exterior finishing and forested living roof, HAC project co-chair Barry Trass said.
"The revised construction methodology requires substantial below-ground foundation work as well as the complete deconstruction of the existing NRC building. All materials suitable for recycling and repurposing will be salvaged from the building, removed from site and brought back to be incorporated during the finishing phase of the project," he said.
The new designs and regulations will not require any additional budget above that which has already been raised, rather a change in approach, Mr Trass said.
"By ensuring we not only meet but exceed current regulations, we are creating a lasting asset for our community and generations to come. It is of the utmost importance that we do this once and we do it right," he said.
"While we acknowledge that the change of approach is reasonable, the end result will be as originally imagined by Hundertwasser himself. We intend to stay true to the artist's own philosophies by recycling any and all suitable materials from the NRC building and reusing them in the reconstructed building."
The new construction plan has been approved by the Hundertwasser Non-Profit Foundation. Foundation head Joram Harel said Hundertwasser had several projects where the old structure had to be demolished out of necessity.
Mr Trass said the latest statistics from MBIE show that total tourism spend in Northland has increased 20 per cent since the original HAC economic impact calculations were done.
"This means we can be confident that the project will bring more than $26 million each year into the community and that the Northland region will have generated more out of this project in just a single year than what it would cost to build," he said.