Yes, they are both by the Percy Thomas Partnership of Cardiff. Personally, I think the Arts Building works better than the Library, and together they successfully complete H.T. Hare's plan for an outer quadrangle. Percy Thomas Partnership also designed the brutalist concrete Brambell Building (Zoology) of 1969 in Deiniol Road - a building which you either love or hate. I love it - Bangor needs more exciting modern buildings - I'm very hopeful about the Pontio project.
You will either love Deiniol Road with living proof of architectural history; from new modern wooden buildings, to old stone buildings to 70's style concrete building - or you will hate the pick n mix style to this road!