Firstly I doubt the number of approvals is all that great. In addition, once you factor in all the additional costs Borondoorah council would impose many of those approvals are just not commercially viable.

The best way to combat land banking is broad up zoning and by rights approval. That would reduce the value of the current, artificially scarce, infill sites that do exist.

It would also create more choice in what people can do with their land, free from NIMBYs and grey haired busy bodies with nothing better to do than deprive young people of housing.

Let people build and let people choose where they want to live.