After a few days of limbo, having started my postgraduate course in DCU, I still wasn't able to get into the secure(ish) research bay. Nagging to the school office did no good, so I went to the Estates office in person against the recommendation of the school secretary. Handily, the lass in the Estates office swiped my card, noted that I hadn't had privileges to open those doors added and dragged the equivalent permissions onto my set - all of 2 minutes' work.
Then I went back to my desk, without having to wait for someone to let me in like an orphan boy, and waiting around for someone to set my nicked (from someone who hopefully wasn't using it anymore) crappy Pentium III PC to allow network logins.
I'm going to assume that this amount of hassle, bureaucracy and poor inter-department communications is a normal thing.