The third wall has been chinked and daubed, and I can smell the barn. This is very hard work. The last remaining wall has no windows or door -- that'll be easier in a way but overall more difficult -- more to do. I've decided that wool insulation will invite pests and dust. I'd use fiberglass bats if I were going to chink and daub the inside walls, but I have no more energy for such and also want to avoid any crumbling concrete dust on the interior. Spray foam insulation is the way I'll go. It's not cheap, but it does seem to go a long way. It's insulating and it's hypoallergenic. It'll cover the back of the lathe nicely. "Good Stuff," to be exact -- whether that's a description or not it's soon-to-say. If it looks ugly, I'll cover it with ripped strips of wood, which could be stained like the walls.