fence
A nonarchitectural fence or partition installed at the top of a structure as a tip element.
A fence, as a tip element, is a partition installed at the top of a structure which does not belong to the architectural design of that structure.
The partition is an added top element rather than part of the structure's architectural composition. Its material can take the form of wires or webbing, as in the accompanying short description.
A perimeter fence at ground level does not have this top-of-structure role. An architectural parapet or other designed crown differs in belonging to the building's architectural form.
