As far as I'm aware the proposal is to build the 180 new homes on the caravan site that occupies the site of Rockhills (originally John Paxton's house). This site was never part of Crystal Palace park so I don't understand what the fuss is about. Where's the money to improve the park going to come from if the housing is blocked?
If you look at it on Google Earth, it looks like a parking lot with trees, with some caravans parked there. Does anyone else have any information on it?
One of the things I was struck by when I moved here is how much open green space there is for such a dense city. When you read about towns being built from scratch in the middle of nowhere on what is currently conservation land, it does seem as though there is an argument to be made that it would be better to infill some of the open space in cities, where there is already infrastructure, if the expected population increase is to be housed.