I have a spot that in the garage where there is an offset that I could easily get a 12'x12' room, possibly 12'x14'. I was storing the split wood right outside the doorway for the other one anyway so I don't really need the storage room and could easily just carry in what I was going to burn/load each time, thus keeping the area relatively clean of debris. The flat part of ceiling finishes out just shy of 11'. I have it all drywalled now with 5/8" firestop but my plan would be to build 2 walls around the inside to close this off from the rest of the garage and then line everything with ag steel. There is a window on the exterior wall and then of course an outside door. It would keep it closed off from the remainder of the garage, the only draw back is having to go outside to enter the room, but that's still not as bad as standing outside the whole time. Had no issues with the insurance company outside and they didn't squawk when we contemplated putting a fireplace inside with the original build as long as it was UL approved. Still weighing all of my options. Id' like to see what others have done in an enclosed/insulated structure, not just a building meant to shelter the stove and some firewood.