Australian Racing Hall of Fame Legend Gai Waterhouse has described the potential sale of Rosehill racecourse as the saddest decision ever made.

In a radical proposal from the Australian Turf Club being considered by the NSW government, a $5 billion price tag has been put on the land in Western Sydney which would see 25,000 new homes built, a new school, entertainment facilities and green spaces.

The Rosehill racecourse is home to the world's richest two-year-old race, the Golden Slipper, a race which Waterhouse, who trains at Randwick with Adrian Bott, has won six times.

"I think it's the saddest decision they've ever made," Waterhouse told RSN927.

"I think the government are completely wrong. I don't think they've thought it through and haven't done their due diligence.

"I bet there's not one racing person there that has any idea."

If the proposal goes ahead, upgrades would be made to Sydney's other racecourses – Randwick, Warwick Farm and Canterbury – along with a new racecourse built at a yet to named metropolitan area.

"Once you lose it (a track), you never get it back," Waterhouse said.

"The same thing happened in Paris when they lost Maisons-Laffitte. The same thing happens the world over, you don't get the racecourse back.

"The government rush into things and don't think about it.

"Take a deep breath and consider the impact on all those that live there."

Waterhouse was one of a number of industry participants who had their say the morning after the announcement that was a surprise to most.

Richard Freedman, Rosehill trainer: "For the seven trainers (based at Rosehill), we would see it this way – it's a big proposal, it could be great for the racing industry and it could be really bad for us, or really good, we don't know," he told Sky Sports Radio.

"I think we take the view that if we're being asked to uproot our stables, and largely uproot our lives because a lot of staff have children in school around Rosehill, Lee Curtis, a trainer there, he has young children in school there.

"We will have to uproot a lot of people and move, perhaps into a completely different area, we don't know where that will be.

"But if we're going to be asked to do that, it has to be substantially better than what we have and that's pretty hard, Rosehill is pretty good.

"It can't just be as good, it can't just be a little bit better, it has to be substantially better."

David Payne, Rosehill trainer: "I think it's a good thing, it's a win-win. For the horses, it will be much better. Rosehill is a bit of a concrete jungle, the horses just go from the boxes to the track and back and then out of their boxes onto the walker. At least out there they can put paddocks up for them and it will be much more open," he said.

"If they do it right, it could be a showpiece of the world. But they must get trainers involved and people to help them plan it, don't leave it to the businessmen that know nothing about horses. You've got to get the right people. At Randwick, when they put those horse stalls in, they left it to the committee and they were too small and had to redo them. They need to plan it properly and it could be a showpiece.

"At the end of the day, it's better for the horse and that's the main thing. They will have a better life."

Annabel Neasham, who has a Rosehill base: "Obviously Rosehill has been a historical racecourse, it's a fantastic racecourse, and the thought of losing it is very sad, but on the flip side it's going to generate an awful lot of money that can be pumped back into facilities (and) probably a new track. I don't know the ins and outs of it yet, but I do know that it will completely change the whole outlay of racing in New South Wales," she told RSN927.

"While I think part of it is a bit sad, I think you've always got to look forward and I think it's going to be a huge opportunity for us trainers and participants in New South Wales. I think it's pretty exciting actually."

John O'Shea, Randwick trainer: "I would be concerned. It's the jewel in the crown of the racing industry's asset base. There are a myriad of concerns that need to be talked through.

"There are historical precedents and the best guide to future behaviour is past behaviour. The industry has previously had a number of tracks around this (Randwick) area, Rosebury et cetera, in the past which have been sold. What have we got to show for it? That would be issue number one.

"Issue number two, with the $5 billion, they are intending to do a major development project. That will be a necessity because they need to replace the track, they need to replace the training facilities for Australia's biggest trainer (Chris Waller), number one, and a proliferation of other successful trainers in proximity to Chris.

"It's suffice to say the industry doesn't have a very good record in project development and I don't think anyone would deny that.

"It's of no consequence to me, but if I'm looking at the whole thing purely objectively, there are a myriad of questions that need to be asked by good people."

David Eustace, who has a stable at Warwick Farm: "Reading it, it sounds like there is a plan in place and if it's done properly then, undoubtedly, the facilities at Warwick Farm need improving from a stabling and track point of view so if they pull it off, I think you've probably got to commend the foresight."