In a statement Auckland Council's chief of strategy, Megan Tyler, said it had until June 17 to lodge the appeals in the Environment Court.
"The council is committed to continuing to work with the private plan change applicants and other parties whether that is through court-directed mediation or other avenues," she said.
"Given the council's appeals are yet to be lodged, no further comment will be provided until the court's appeals period closes on June 17, 2022."
The Auckland Council's planning committee voted on Thursday to take legal action, but a report from officers on the issue remains under wraps.
The developers applied in July 2020 to rezone the land in East Drury from future urban to a mix of residential, business and open space zones.
The council has continued to oppose the plan changes on the grounds it would be left to foot the bill for $1 billion in the infrastructure needed for the works to go ahead, including $600 million for transport-related projects and a further $500m for stormwater, sewerage, parks and community facilities.
In October 2020, Tyler said the Drury private plan changes would ultimately have to be decided by the courts.
Fulton Hogan land development chief executive Graeme Causer said he was still trying to get his head around the council's decision.
"All we'd heard was a rumour that the council was going to appeal."
Causer said it was not the news he wanted to hear.
"It's a waste of money for everyone involved."
The land had already been earmarked for future growth under the Auckland Unitary Plan and the council was merely delaying the inevitable, Causer said.
"I'm hoping common sense will prevail. We're trying to build houses, isn't that what everyone wants?"
Auckland deputy mayor and Franklin ward councillor Bill Cashmore said last month he supported the decision to approve the private plan changes, which would see a town the size of Napier eventually built in Drury.
It made perfect sense to develop the area because of its location right beside State Highway 1 and the city's rail network, he said.
Cashmore did not know at that stage if the council would appeal but said he did not think it would achieve much and would just add another $1m to its legal costs and another year in delays.
The total population of the Takanini, Drury, Opāheke, Paerata and Pukekohe areas is expected to grow to 120,000 people over the next 30 years.
Both Kiwi Property and Oyster Capital were approached for comment for this story.