The High Court has given a "green light" for more than 400,000 extra homes across Auckland over the next 23 years, developers say.

Justice Christian Whata has rejected heavyweight appeals by residents' groups Auckland 2040 and the Character Coalition against the new Auckland Unitary Plan.

Property Council chief executive Connal Townsend, who represents developers, said he was "delighted".

"Fundamentally it means that the Unitary Plan, as originally approved by the council following the report of the independent hearings panel, is given the green light to go," he said.


"What the Unitary Plan finally delivered was 410,000 new homes [by 2040], which we think as a plan is probably just about exactly what we need."

The residents' groups argued in their appeal that the hearings panel went beyond the scope of the original proposed plan, and of submissions on it, by moving about 29,000 residential properties into more intensive housing zones than proposed in the first draft plan in 2013.

But the court found that developers, notably the Government-owned Housing NZ, had proposed all the changes in submissions on the original draft.

"There is nothing 'left-field' about the recommendations or the submissions," the judgment said.

Barrister Richard Brabant, who represented the two residents' groups, said special legislation which set up the Unitary Plan process allowed no scope for appeal against the High Court judgment by the 29,000 affected residents unless there was a case for judicial review.

"I believe that the council is in a position to bring the parts of the plan relating to those properties into effect," he said.

But Character Coalition chairwoman Sally Hughes said the decision meant "thousands of homeowners have been denied a say in what happens to the streets they live in".

"While we accept the judge's decision, we are very disappointed with the outcome," Hughes said.

"We do not feel that the 29,000 homeowners, on whose behalf we made the appeal, have had an opportunity to be heard.

"It will now be death by a thousand cuts as developers move in over time, and destroy the character of some of Auckland's most beautiful streets."

Townsend said he was not worried that a fall in house-building permits issued in Auckland in December showed that the required extra houses might not be built because the banks were tightening up on credit.

"When the banks do something to tighten up, it does provide a market opportunity for other players to come in," he said.

But he said the plan's approval still left other issues to resolve including a shortage of skilled builders, low construction industry productivity and a large proportion of new homes being failed by council building inspectors.

"It's quite clear that, as the private sector is almost unable at the moment to cope with the amount of demand, therefore now with this green light to go, the obligation is on the private sector to front up to meet that demand and deliver quality product," he said.

"There is a huge obligation there now for the private sector to step up and perform."