For very very cold climates, you can use an old fridge or freezer for roosting. I lay tall ones on their back so that the door becomes a door on the top. In what is now the side of the fridge, you can drill through with regular drill bits, you can cut (use gloves) the sheetmetal using tinsnips, or if you have no tinsnips, you can use an angle grinder (dangerous) or an old knife or lawnmower blade. Put the blade or knife into the hole and hit the back of the blade with a hammer in the direction you want to cut. Good idea to cut larger than the chook by enough margin to line the hole with wood, so the chooks are not tempted to eat the insulation. If the fridge is put into the chooks current coop, you'd have to wait until after they settle in for the night on the old perches and then move them into the fridge for up to a dozen nights until they learn to go in themselves. If it is a new coop or chicks, they get the idea straight away. I've done this many times so I can advise on whatever is not clear if I am still here. I originally wrote this as part of a different thread, but it is better as it's own topic. I can post some pics however it is just a fridge as described. Chicks love it in cold weather, I had a light on inside one that was outdoors, you MUST be careful with that because any standard light bulb or heat lamp will cook the chicks no matter how cold it is outside, at least in the daytime. I didn't lose any, but you need a timer bare minimum if not a thermostat. Any size of chook likes this arrangement and obviously it extends the laying period into and through the winter because they have an area to make an adequate nest and raise chicks, so with enough food, hormones do the rest. Mine lay through winter when everyone else in town say theirs have stopped laying. The surprise advantage of the light at night to keep the chicks warm is that lots of bugs fly in during the early evening giving the chicks a feast and lots of practice catching, and it's free, they love it. edit: I think because of all the allergy to something different, and what I think is hysteria, I should have called this thread "How to raise Zombie chickens" and then the same people might say (I think) things like "It'll never work, they'll just breathe air coming through the door!" Here are some pics I finally got out of the silly phone. here is the inside and outside view of a door in a fridge I have been using for some time to raise different batches of chicks outdoors *including during freezing winter conditions* note the fridge shelves used as walls of the enclosed outdoor yard for the chicks. This is another one, where I have built some nest inside, not shown because not finished, still working on a mechanism that closes wooden internal doors to give the hen privacy so chooks don't use the same nest 4 at a time. still working on that part.