Where is a good quiet place to get my personal work done?

I am referring to work outside of my daily 8–5 job. When I get home, I like to use my personal time to do research, read, or reply to e-mails. The problem is I’ve never been able to work well in my own home environment. I have adult ADHD and there are too many distractions, plus I live with 2 other people. In college, I dealt with this by finding the perfect environment for myself, which was usually a quiet spot in the library or an empty classroom.

Now I’m in the real world, and there are no empty classrooms to camp out. The nearest libraries close at 5 PM most days, and coffee shops: not a chance. I need total silence and no time limits (such as closing times) to really be productive. Where can I find this now outside of college?