I have a drafty old barn I want to convert to breeder pens. With all the cut outs and patch overs for chicken doors, stall doors and whatever else, it's a patchwork quilt of boards. I also have close neighbors, so all roos currently have to go to the cellar at night. Most people do the outside of the existing structure. Unfortunately I cannot tear down to studs any of the outer walls and I can only cover them up with something thin like siding. I can do anything I want to the inside however.
So far the straw bales are looking messy because I would need to coat the backside for waterproofing before putting them up and then doing the front. I wouldn't have to with the earthbags. Heck, I wouldn't even need to do a nicer finish on the inside if I didn't want to. Definitely going to be looking into it.