air rights
Air rights are the rights which a landowner has to the space above that land. It used to extend forever but with the advent of air travel it was limited to the air space that was connected or in some way usable in relation to the land. There are ways in which this ownership is developing into a market in air rights.
One idea is that the unused space above a heritage building is auctioned off to private developers who can then add that space to buildings they have under construction elsewhere in the city. The space above the heritage building is never used and the purchase money is used for conservation purposes.
Private owners of property can protect the view which they value and which is an integral part of the price of their property by buying up their neighbours’ air rights. It may be worth it to them to keep the value of their own property by ensuring that the view is never lost.
The sale of air rights is not common in Australia but there are cases which have provoked discussion about developing the rules for such transactions.