Quick thought - are you really just self-conscious of your neatness? I still live with my parents () and I HATE it when they just barge into my room at a moment's notice. Though that's only because I'm worried they'll see/find my weed stash and kick me out of the house. Otherwise I don't care at all. Their house, they can do as they please, I'm just grateful they go to such lengths to accommodate me. Though if you're paying rent, your dad is out of line. If you really tried to level with him and let him know how you feel and he's still overstepping his bounds, I'd say he's the weird one who can't stay out of your shit for some reason, not you who just wants some privacy/respect. Unfortunately, the only real solution is to do whatever it takes to move out on your own.