A principal of the marketing company for the Heathcote Hall estate development is confident prospective buyers won't be deterred by the strong opposition of local residents to the project over many years.
Dennis Vertzayias, a director of the exclusive selling agent Laver Residential Projects, said he believed any reservations would disappear once people saw the effort that had gone into planning the development and what was on offer.
Advertisements have invited people to register their interest in the project, called Heathcote Grounds.
An expressions of interest campaign, designed to gauge the market response and guide pricing, will follow within the next few weeks.
An off-site sales office will be visited by appointment.
A three-year campaign by local residents failed to stop the development being approved in December 2019 by Sydney South Planning Panel in a 3-2 vote.
The project includes refurbishment and restoration of the 1887 mansion and construction of 35 townhouses and 20 apartments, with extensive landscaping, in the grounds of the 4.5 hectare estate.
Mr Vertzayias said, "I have been down this road before with this type of development and I understand the sensitivities and I am extremely respectful of the local residents".
"At the same time the the development has been approved and the reality is it's going to happen whether people like it or not," he said.
"Are people going to be deterred because there has been opposition? - Personally, I don't believe so.
"I think when people get to review the development, they will appreciate the huge effort that has gone into planning it.
"This is not a substantial overdevelopment. The majority is two storeys, in keeping with the surroundings, and there has been a huge effort to keep the majority of the existing trees
"The rejuvenation of Heathcote Hall - bringing it back to its majestic appearance - is a massive win for the local community.
"Unless someone came along to invest in it, it would have stayed the way it looks now."
Mr Vertzayias said there was no information available for prospective buyers on how the restored hall would be used.
Mr Vertzayias said it was hoped work would start next year, depending on sales, with a construction time of 18 months to two years.
John Innes, chief executive of development and project management company Pariter, said, "We are very excited about the upcoming marketing launch of the Heathcote Grounds project, which will include the full restoration of Heathcote Hall and the release to market of high-quality, low-rise townhouses and apartments".
"Meticulous planning and extensive consultation has taken place to ensure the heritage value of the existing buildings is maintained and breathes new life into an iconic site," he said.
"The project is a result of a collaboration between Pariter and an experienced team of project consultants and will ensure Heathcote Grounds becomes one of the shire's most liveable neighbourhoods".
Patrick Kennedy, a Heathcote east resident and member of Residents against over Development (RAOD) said, the state government's Sydney South Planning Panel had decided "this massive over development on the edge of the Royal National Park to go ahead".
"The recent out-of-control fire, which once again turned Heathcote Oval into Heathcote airport with waterbombing helicopters using it to refuel, showed the community that this decision was indeed very poor," he said.
"The fire and uncontrolled evacuation risk is massive.
"All the arguments are in and we are stuck with the decision, as wrong as it is.
"Recently trucks were used to remove hundreds of stored concrete blocks from the site and trucks were roaring up and down Boronia Grove above the speed limit and in a dangerous manner.
"To the foreman's credit when this was raised with him he was most sympathetic and took the complaints on board.
"We ask that the builder respects local residents by having truck drivers drive sensibly and to share the load around all the streets- not just Boronia Grove and Dillwynnia Grove.
"There needs to be some sensible planning and community consultation. This would obviously be a good public relations step."
Mr Kennedy said residents were also very concerned with the large trees and palms in Boronia Grove and Dillwynnia Grove and also Tecoma Street.
"We ask that every one of them is protected as was promised by the council in the consultation process.
"This decision by the state government will change the very nature of this quiet tranquil suburb and we once again ask the developer to respect local residents by operating only during the hours allowed under the DA and avoid unnecessary noise, dust and general disruption."