Ah, good to see it's not only my problem working it out,
From The Independent:
'...nestled under the asthma- inducing Waterloo Bridge, on the site of a former car park, the NFT isn't feted for its architecture: its press office couldn't name the original architect or the cost of the building, which was extended to two auditoriums in 1970. The more elegant Museum of the Moving Image, designed by Brian Avery and tacked onto the NFT in 1988 to provide an additional cinema, cost pounds 12m.'
Thanks for the responses guys! I've been frantically searching the web and apparently David Chipperfield designed the building in question. Unfortunately here is nothing in the way of drawings, pics (or even written text) on his website about this project! James Hatts, you're right about David Adjaye and the Mediatheque. I'm actually in Glasgow and without having visited the complex it's hard to get a picture of where the building sits. Thanks once again