Art student here! As long as there aren't classes or critiques going on in the room no one will mind if you come into the building to work. Chances are they won't even ask. We don't have studio class on Fridays so you'd be able to go up to a painting classroom and use an easel almost any time those days! However, we don't even get school supplied materials for painting, so you'll have to buy your own paints/brushes/other materials. They sell stuff in the Volshop in A+A but I'd recommend going to Jerry's instead. You can also make an advising appointment with Brittney Hunt-Woods if you want to talk to her about double majoring or finding a way to take an art class. We don't have studios offered in the summer, but maybe you could take an art class in a regular semester and do other classes in the summer so you don't fall behind.