I live in the south-west part of BC. Earlier this year, (early summer) we got a flock of mix breed chickens. So far this year at night, temperatures have been as low as 2 Celcius, and with wind chill, -2. One year, it went down to -21. We have quite a large coop for them, Tall enough for a 5' 3" person to stand easily in it, wide enough for 3 horse feeding buckets (nesting boxes, about 2 feet long) and a chicken door, as well as deep enough fora person too walk a few steps... if not for the roosts, so about 8.5 by 6 feet or so. We use white softwood bedding, only one or two inches as we were getting low, but we will be putting in more soon. We have 5 laying hens, and a rooster, all under a year old, and a few Muscovies we may or may not be keeping. We might be sectioning off a small bit of the coop for our two rabbits in the non-winter months. We have no idea the breed of our chickens... We have a large white-ish yellow-ish rooster with a small crest on his head, two white hens, a white hen with a slight white crest, a white hen flecked with browns and black, and a black hen with red on her chest and a mid-sized black crest. They all have single combs. Is there anything we can do to the coop to make it warmer for the winter? I'd rather not use electricty, in case of a power outage, but we have it in our horses barn, so if push came to shove, we have it.