I recommend doing an admin room. Not a room where our admins would be, but a room with special buttons which cause stuff to happen. Say, sudden zombie invasion.
Try this Star Trek map for good example. It has an admin room that turns on alerts, causes meteor attack and there's an option for klingon attack too, not to mention the engineering room where you can turn off lights, life support and activate self-destruction. There's also several other buttons on the bridge and all around the ship.
http://www.garrysmod.org/downloads/?a=view&id=33631