I worked on many access systems that hung a reader on only a single door within the building perimeter: the server closet. Granted, there might be 4 or 6 doors that faced outside area that were all controlled - but it almost was an unwritten rule the server room or telecom closet was controlled too.
This makes sense to me: physical security trumps logical security, but only if implemented properly.
It always amazed me at who was given access to that room. Sure, as far as 'regular' employees, only the IT staff would have exclusive access.
...but the cleaning crew, maintenance staff, contract security guards, and so on, those folks were given access too. Indeed, I have seen a service call on account of a janitor wet mopping near a server rack.
So my question is: Who typically has access to server rooms? Do you advise or enforce a certain level of access control to your video/access/data servers?