Rooftops which have not the top of the structure,usage up and legislation of independence,can not be the object of condominium ownership by itself,and not have parts of ability independence important item particularly (Sondereigentum) of the owners on the toplevel.Rooftops must be the objective of the joint ownership,and can be set exclusive use right for special owners or the third parties beyond the owners.Exclusive use right can be stipulated by management rules or the decisions of the owners'meeting,and can not be set by the builder in the building sale contract.