Initial investigations have begun into how to fix one of New Zealand's biggest leaky-building towers.

Owners of Takapuna's Spencer on Byron hotel/apartment block have employed a group of experts to ascertain how to fix the 249-unit complex.

Robert Khoo, chairman of the owners' committee, said that would determine the scope of the construction contract.

"The body corporate committee is in the process of obtaining the scope of remedial works required which will form the basis of the tender to establish the total remediation costs.


"For the investigative work currently under way, we are working with a team of construction consultants such as Facade Design Services, MSC Consultants, Mott McDonald, Ethos Project Managers and Barnes Beagley Doherr," Khoo said.

The owners initially lost High Court and Court of Appeal litigation, but then won a Supreme Court decision, resulting in a settlement between them and the former North Shore City Council.

The exact amount they won is confidential but it is thought to be many millions, allowing them to go ahead with the huge fix-up.

But Khoo expressed frustration about the length of time it has taken to progress to the point where a contract might be let.

In October 2012, the Supreme Court said the former North Shore council owed a duty of care to ensure the Spencer on Byron development complied with the building code.

The 249-residential unit complex, 200 of which are leased to a hotel, was certified by the council but was later found to have defective cladding, it was reported.