When we build our garage, I made sure we added a 2nd floor, for storage space, etc. but it turns out to be our studio. Half is for my quilting area w/ big tables and the other half for dh trains. Add a pellet stove n perfect solution to keeping it warm in winter when we need it. Good luck planning yours.

TV in room - DH and I tend to like different programs - are you TV watching compatible?
Also - my DH has a more severe hearing impairment than I have - and he likes/needs it several 'notches' louder to hear it easily - and that is where it starts to be painful for me.

Make sure that you have a/c in your new "bonus room".

WOW what a wonderful project! One thing I would suggest is "pull down" outlets from the ceiling. The ones at my LQS retract to the ceiling when not in use. Makes even the center of the room usable by electronics without tripping over cords.

we have a shared room (its a 4 car garage behind the 2.5 car garage !LOL), we love it .. I can be sewing and he can be working on his current project and we can talk about what each is doing ..