As someone in the same area, I'm curious if you did this post-grad-school? I can't imagine the co-ops in e.g. Kerrytown are very welcoming of non-students, but I don't know.
Being a non-student, I needed approval from the house. Being student age and working on campus, it was easy to get - but it's sometimes granted to people for whom neither of those is the case.
I lived next door to the co-op at State and Catherine, and there were a few people who lived there who were in their late thirties and definitely not students. I don't know about _all_ of them, but some definitely don't care if you are a student or not.
Unless things have changed in ways that seem very unlikely, every ICC house "cares" in that non-students need house approval and students (generally?) don't. But houses will certainly vary in terms of how easy it is to get that approval. They will also vary along many, many other axes.
