In the meantime the historic homestead has no protection and could be lost.
Work to clear the site for development began earlier this year. A smaller bungalow at 13 Coronation Rd was demolished and extensive vegetation removed.
The Herald can reveal that Treasure Plus lodged a resource consent application earlier this year to build 21 townhouses on the combined 2700sq m site.
The application followed a story in January revealing the two properties had sold five times in just four days.
One of the homes surged in price by $400,000 during that time - and their collective value jumped by $550,000 in less than a week.
Heritage New Zealand's Auckland regional archaeologist, Bev Parslow, told the Herald the council's heritage assessment discovered evidence of pre-1900 human activity on the site in January.
The area was thought to have been "gardened by Maori" and used as a "shell midden".
"There was an earlier building thought to have been within the general vicinity and possibly underneath the foundations of the George Courts buildings. There's reference to a building being relocated off site to make way for that George Courts building."
Records suggest the homestead was built in about 1920, though there are also records referencing it being barged to the site from Remuera in 1910.
Parslow said that after recording the site's archaeological significance, the council alerted Heritage NZ to vegetation clearance works on the site, with officials sending images of the clearance activity.
"As a result we proactively followed up with the owner and advised them of the archaeological provisions of the Heritage New Zealand Pouhere Taonga Act and their obligations. We understand that work has since stopped in order for the archaeological authority process to be followed."
Treasure Plus Ltd had recently employed a consultant archaeologist to assess the site and lodged an archaeological authority application.
This would allow it to disturb or destroy an archaeological site once information about the site had been properly recorded.
The application had been sent back to the company for further information and a new application was expected.
Meanwhile, work at the site has halted to preserve any important historical signposts and ensure they are not lost forever.
It is unlawful for anyone to modify or destroy an archaeological site without the prior authority of Heritage NZ.
A council spokeswoman confirmed council staff had alerted Heritage NZ to the site.
"In regard to the heritage assessment, the wider evaluation process has not yet been completed so unfortunately we're unable to provide you with anything at this stage. Once it is completed, it will be reported to the Planning Committee."
A resource consent application for 11 and 13 Coronation Rd had been received but was on hold awaiting further information.
Treasure Plus Ltd has been approached for comment.
