Definition of permanent open space?

Question

Legal definition or interpretation of open space in cluster housing developments

Answer 1

The best definition of a permanent open space is the inside of the head of George Bush.

Answer 2

It's space that cannot legally be built on in the future, usually both because every housing unit's deed contains a promise that it will remain open space (so it only takes one person to block a change in use) and because the local government zoned it that way as a condition to granting the building permit.