Residents in a swanky $700 million Auckland housing project have been ordered to vacate their homes amid fears they are structurally unsafe.

Urgent remedial work is now under way on 22 homes in Kensington Park at Orewa amid concerns about "bracing elements" in 11 buildings.

Bringing the properties up to required standards is expected to cost hundreds of thousands of dollars.

Auckland Council, which signed off the dwellings, was alerted to problems in February after the developer Kensington Properties reviewed design documents and identified the structural problems.


"They contacted us to advise they had some concerns about some bracing elements to a group of buildings built under 11 separate consents, and were voluntarily undertaking work to remedy this," said council building control weathertightness and compliance manager Sally Grey.

"The works were not as a result of any actual failure of the buildings that we are aware of."

The repairs were due to be done early next month. The developer would then apply for retrospective certification.

Ms Grey said the council granted affected buildings code compliance certificates between October 2013 and June 2015 on the advice of experts.

Council building control general manager Ian McCormick said the council relied on the expertise of certified engineers to confirm work met the building code.

He "commended" the developer for coming forward.

Properties range from one-bedroom apartments for $590,000 up, through to townhouses, duplexes and standalone homes - with many selling for well over $1 million.

The project has a troubled history. The then $450 million development went into receivership in 2008 having completed only about 60 of 750 planned homes and owing millions to creditors.


It was resurrected the following year when it was bought by millionaire industrial land developer John Sax.

Kensington Park general manager Gary Noland confirmed 11 two-storey duplex homes - housing 22 inhabited dwellings - were affected by the design problems.

The rest of Kensington Park's buildings had been checked and met design standards, he said.

"We have moved quickly to address the issue affecting the 11 buildings. Owners of the homes have moved out pending remediation work. Remediation will fully address the issues identified."

The urgent repairs were being peer reviewed and would cost between $20,000 and $40,000 per building at no cost to residents. Property owners were expected to be back in their homes by early next month.