It depends on when the building was constructed.
The NEC is not retroactive.
That said, it is possible that there are local amendments, building codes specifically for rental properties that may require somethings to be brought up to present code.
In my area GFCI outlets need to be installed in rental properties meeting the new codes. However we would not have to update the lack of circuits.
[This message has been edited by iwire (edited 10-12-2004).]
