Moos mom said it best. Cats do not like change. When Bean and I moved in with Moon, we actually refinished the basement and made that room "his". Then, we got Sunny and tried to make the basement Sunny's. Bean was pissed! He wouldn't sleep inside, he walked around crying constantly. I came on here and asked for advice. I was told "cats do not like change. The basement was Bean's first; give it back". Hehe. That night, we moved Sunny upstairs to sleep and gave Bean the basement back. He's been back to normal ever since. I know that giving your cat an entire room is probably unlikely but see if there is anything you can do to let him have his own space. I hope that helps.