We've got our first five ladies brooding indoors, and we're planning on building/converting our coop this weekend. The building is a preexisting structure, concrete floor, wooden walls, shingled roof, several windows. The building is not insulated, however, and this winter has been brutal. My question is, do we need to insulate the building before next winter, since temperatures well below freezing are becoming more the norm here in south central PA, or will our ladies be ok with DLM and a water heater only? Anyone retro fit another building for a coop have an issue with cold?