My previous layout back in New Orleans was 12x12 around the walls with a peninsula. Now it's a 3x6 Scenic ridge layout in my 10x10 office here in the house we're leasing in Houston.
We'll be shopping for a house in December to buy in Jan/Feb and you bit I'll be keeping an out for "train room" to use.
I really would like to do HO scale for my next layout, so if I can't get a decent sized in-house room, the garage will be my next train room.