There aren't any Durham colleges with studio rooms, per se. However, Hild Bede college currently occupies the Unite Students Rushford Court building, which does have studio rooms, and Castle offers some students accommodation in Kepier Court, which also has studios. If you are an undergraduate, it is unlikely (not impossible) you'd be allocated a studio room in either of these, as that kind of room seems to be most often offered to postgraduates. If a studio is a non-negotiable for you, I would recommend looking at private halls such as Dun Holm House, Student Castle, CityBlock Village @ The Viaduct, or Ernest Place. But if the studio is simply a preference and you'd be content with a standard (shared bathroom and kitchen) or ensuite room (shared kitchen), I would definitely recommend trying to live in college in first year for the social aspect!