The first thing I thought about here was the process the Rolling Stones went through while recording Exile On Main Street. They were tax exiles in France at the time, and the house they were living they also recorded the album in.
It was an old house that was not built with acoustics in mind, so they adjusted their instruments as much as they could to get a good sound. Charlie Watts for instance laid down his drum tracks in the basement because he felt the sound was better down there than in other rooms.
So sometimes it's not about adjusting the room, but adjusting how and what you play in any given room.