ALL of our archives are SUPPOSED to be, too. But we're generating so much information--especially due to digs mandated in advance of construction work--that it's far outstripping the space and funds allotted to it. And if you google "archaeological records storage space crisis" the first hit is a bit of tongue-in-cheek responding to http://www.britarch.ac.uk/BA/ba12/ba12comm.html. Of course that was ten years ago. Has your British situation vastly improved since then? From the few articles I've just skimmed, it doesn't seem so, but I'm no expert.