Actually let me rethink that comment I made about "He treats this as a place to sleep and that's pretty much it.".
He doesn't want to get an apartment for a few reasons. (1) money, (2) the hassle and (3) he wants this house and expects me to leave so he doesn't want to move out only to have to me move out the shortly thereafter sticking him with a long lease. (In our asset split, he gets the house.)
So he has been going up in his room and surfing the web. I'm pretty sure last night he was watching a movie when I went to bed. He does come down to talk to me. I told him if he wanted the living room just let me know and he said "not now but maybe later". He never did ask for it but he's a bit more open to it.
Yesterday I cleaned up his room and moved the rest of his clothes in there along with a small dresser & put all the laundry away. I rearranged the room a bit and moved some stuff out so he would have more room. I unpacked his "to go" bag and just did a lot of little things that I know he likes to have (nailed a clock to the bathroom wall so he can keep track of time when in the shower, made sure he had a power strip and all the plugins for his devices, etc). I knew doing this could possibly backfire but I want him to be comfortable and if he has a "cave", maybe that will help a little. I can't really help the flow of sound in this house though...