Hi. I am converting a nice pine shed into a guest house for company. It is a simple but solid pine plank building with no insulation or siding. I am wondering if I can just put in fiberglass batting between the studs and put a vapor barrier over that, than put up a nice interior wall. Does that make sense, or should there be a barrier between the outside wall of pine planks and the insulation- since there is no siding or tyvek or anything to protect from rain moisture. What do you think?