great start!! we don't insulate and we're on the east coast right on the ocean. We use the deep litter method in the winter and only on the coldest of days (there were about 5-10) do I throw on the heat light to warm things up for a bit. It might also depend on what breed of chickens you have... mine are golden comets, silver laced wyandottes, RIR, and silver spangled hamburgs and they're all pretty winter hardy breeds.