I have long noticed that questions and posts here on BYC tend to be content specific and follow seasonal trends throughout the year. Now that we are getting pretty deep into winter and serious cold is setting in, the current "hot" topic.......is dealing with cold weather. The #1 concern seems to be the bird's comfort in cold weather. Some of it speculative. That is understandable. Some of it desperation, seeking emergency solutions to serious problems that have already arisen. That is unfortunate. FYI, there are folks on BYC and elsewhere who manage to keep chickens in unheated housing down to -30F and worse with no serious issues, yet others start seeing signs of trouble when temps drop much below freezing. This is nothing new and appears to have been the case for well over 100 years where keeping small flocks of chickens has been documented. So what gives and what is the answer? As I see it, there are a number of factors to consider but as pertains to the housing, they are: Moisture: IMHO, the #1 issue that affects the success of cold weather housing. The cause of most cold weather problems. Ventilation: Critical for removal of moisture, CO2 and ammonia. The solution to most cold weather problems. Insulation: Depends Heat: In most cases, not needed Lights: In most cases, not needed And lets not forget the birds themselves……not part of the housing, but an important factor just the same as they are the target of the housing and housing needs to be taylored to them. First and foremost…..the pampered pet issue of BYCs aside…….do not be tempted to extrapolate a person's response to cold and what we feel as being applicable to our chickens. Our chickens are different animals than we are and are capable of handling a whole lot colder weather than we are, provided we give them a chance to do so. Birds have their own insulation in the form of feathers and they can adjust those as needed. They also have their own furnace. Body temp of our birds is somewhere around 107F +/-, so they are warm and generate considerable heat themselves simply a byproduct of living. A flock of them huddled together actually generate quite a lot of heat that they are shedding constantly. Fuel for the furnace that produces all that heat comes in the form of the feed they eat, so to stay warm, they need feed and in cold weather, lots of it and it needs to be available to them at all times. To process the feed, they also need access to water at all times. Keeping water thawed is one of the bigger challenges to keeping chickens in really cold weather, but is hugely important. They will struggle to survive at all without water. In brutally cold weather (-10F and beyond) it helps the birds and you if the birds themselves are suited for that kind of weather. Birds with big huge combs and wattles (large areas of exposed extremities) are not well as suited for that type of climate as birds with short combs are.. This is not unique……the same exists in a lot of breeds of livestock like cattle and even dogs, etc. A husky has a better change of surviving in the Yukon than a chihuahua does. But get the housing right and even birds with large combs may come through it fine. OK, back to housing. Here are my main winter survival factors to consider and what to do about them: Moisture: When you boil it all down, the #1 single factor that seems to matter more than any other as far as a chicken being able to survive cold weather is concerned, is moisture. In short, a dry coop is a warm coop, and it's corollary, a damp or wet coop is a cold coop. What a person will generally see as the first sign of cold weather trouble is frostbite. Frostbite on combs, on wattles and perhaps on feet. One grower recently mentioned frost on their birds! So what is the most common cause of frostbite? Aside from being cold enough to freeze, it's moisture and generally excess moisture trapped in the house. This is further complicated by the fact that the source of the moisture is the birds themselves. Moisture in their breath and in their droppings. Moisture also comes from the ground if you have a dirt floor, from rain and snow getting past overhangs and through open windows, from leaking water buckets, etc. One of the very worst is if the coop was placed in a damp, poorly drained location vs. high and dry on a south facing slope with a south facing exposure. But know this, if moisture gets in, it has to get out and ventilation will be the key to getting it out. Rule of thumb is a minimum of 1 SF of ventilation space per 10SF of coop floor. Some will have 2X to 4X that amount. How you do this is up to you, but know this……you have get that moisture out. It is safe to assume that if you are seeing frostbite (or as some report…..frost in general) on birds at less than very extremely cold temperatures, you probably have a moisture problem. An excessive moisture problem. Humidity level inside the coop is probably higher than it is outside and moisture is condensing out. There are myriad solutions but almost all of them relate to moving the moisture out of the house. It starts with ventilation and movement of water vapor out of the house but also depends a great deal on the materials used to build the coop and how it was put together. In the old poultry husbandry books, many of those would start out on the topic of housing by showing a photo of what not to do…….a small, tight, poorly ventilated coop, lacking any windows. In short, a cold, wet, miserable coop. The scary part is many of those old coop photos look remarkably similar to those we see on BYC today, built by well meaning growers (and the builders of those dinky commercial death traps) who didn't realize what was needed in the way of light and ventilation, and so inadvertently created serious problems for their birds. A prime example would be a well built house using uninsulated metal roof and siding, which are notorious for producing condensation. Another is when well meaning growers duplicate human housing by building air tight coops or just as bad, built a really good house, but then feel compelled to close it up tight to retain warmth (and inadvertently moisture). Those are the folks who often report frostbite and other problems where there shouldn't be any. That is the bad news. The good news is many if not most can be salvaged and made to work with a few simple tweaks. Ventilation: If you study the old poultry husbandry books, and even hold historic houses, you will find a whole slew of methods that growers used to vent buildings. Everything from wide open, fresh air houses to those with complex ventilation systems, but in general, the cold weather feature of nearly all of them included designs to remove moisture as the primary factor, with a secondary factor being to retain the heat created by the birds themselves. Complicating ventilation is the issue of excessive air movement or drafts which are felt and described as wind chill. We talk temps, but we also talk about the wind chill factor. So the goal is well ventilated, but no drafts. A neat trick if you can pull it off. Do that and you take wind chill out of the equation. One of the very best examples of well ventilated, draft free housing is represented by the Woods Fresh Air House, a design made popular over 100 years ago. A house built as a modest rectangle but with one short side wide open (and facing south), so it is well ventilated, but in the very back, where the birds roost, the air remains dead calm, even with substantial wind blowing outside. That is the archetype of well ventilated, but draft free. There are other designs that do something similar. The "wide open" and well ventilated concept runs counter to everything we have been taught about our own houses, but it works for chickens because it takes advantage of the chicken's ability to keep itself warm if it can stay dry. Woods houses, if built correctly and managed well, are dry. A number of other "well ventilated" houses are dry as well and they need not be expensive or complicated. So what if you don't have a Woods house and need additional ventilation? There are options, such as cutting holes in walls, adding gable vents, soffit vents under eaves, adding windows, opening windows etc. Much of that will be up to you to figure out, but just know if you have a tight house, and you are seeing moisture condensing and are seeing frostbite, when others are saying you shouldn't, you need get rid of that excess moisture and ventilation will be one of the primary methods. Remarkably, this may be one of the very few instances where supplemental heat may be needed, the main purpose of heat in this case is to dry the air out, not to heat the birds. Insulation: The need for insulation seems to be one of the more common questions folks ask and in my opinion, the answer is "it depends". Probably a good place to consider using insulation relates to where you live and the need to use the heat from the birds (or less likely supplemental heat) to dry out your house. My guess is if you use the USDA plant hardiness map and assume anyone living in Zone 5 or colder may want to consider insulation, you would not be far off. That puts the cut line in around 0F to -10F and below. The frame of reference of the person asking about insulation is almost always from the reference of human housing, and heat retention. The necessity of insulation for a chicken house is similar, but for a different reason. The reason for including it in a chicken house is to utilize the heat produced by the birds themselves to heat the air inside the house to the extent it can to provide some degree of warmth to the birds, and also to dry the house out. Insulation may well increase the temp inside the house by as much as 10 degrees or more over the outside temp just using the heat from the birds alone, and that may be enough to reduce the humidity and drive out the moisture. On the other hand, an uninsulated building with normal single layer sidewalls of plywood, siding, etc, has essentially NO R value. So little if any of the radiant heat generated by the birds is retained. So if temps are really extreme in the range of -10 or lower (Zone 5 or colder), you may want to consider it. Getting the right combination of enough ventilation to vent the moisture, CO2 and ammonia created by the birds, without so much ventilation so as to allow the heat to escape is a seriously tricky problem. Without insulation and adequate ventilation, moisture may well condense on ceilings, on sidewalls on anything including the birds. A really tight, uninsulated house with a high bird population might be dripping wet inside. Insulation is also essential if you used metal roof and/or siding to keep moisture from condensing on the metal. An uninsulated metal roof may actually condense moisture to the point it appears to rain inside. Insulation will also help with metal clad buildings in the summer to reflect the solar radiation and heat gain from the summer sun. In this case to make the buildings cooler in summer as well as warmer and dryer in the winter. There are also valid reasons not to include insulation. First is if they can get to it, birds will peck at it and eat it (foam insulation that is). Also, unless it is installed like that on a house with a vapor barrier on the inside, with solid cover over that, moisture may pass through the insulation (vs around it through vented spaces) to the cold exterior walls, where it will condense, wetting the inside of the building behind the insulation. If that is an untreated wood wall, expect mold and rot and expect it soon. So a person may need to use vapor barriers inside and/or treated lumber so as to avoid mold and rot. In short, insulation greatly complicates the build. Yet another negative issue with insulation is it offers a place for parasites like mites and lice not to mention rats and mice to hide. So if you are in an extreme climate and need to use it, OK, but if not, you may want to skip it. Heat: This seems to be the default position of the pampered pet crowd (term of endearment folks……you know who you are). You want the best for your dears and that is understandable. On the other hand, in most cases, if you got the rest of it right, in the vast majority of the time heat is not needed and worse, if the right conditions present themselves, raising them with heat could prove to be fatal if it ever fails. A bird acclimated to a heated building is at far greater risk of dying in the event of a power failure than just about any acclimated bird is going to face from cold weather in a properly ventilated, dry coop. Having said that, I can think of at least two situations where heat would be recommended (at least by me). The first is a short term emergency situation where a grower has a severe moisture problem and is at immediate risk of losing their birds to frostbite if nothing is done. Related to that is another situation where a record short term cold spell is being experienced by birds that are not acclimated to it. So heat would serve to provide some measure of warmth, plus help dry the house out. Both intended to prevent frostbite. Another situation is in the far northern latitudes where severe sub zero temps (less than -30 on a consistent basis) and short periods of winter daylight makes it nearly impossible to keep birds alive and producing without it. Producing being a key word. It is said that most commercial growers rarely allow their birds to be housed in anything below 30 degrees or so. At that level, with adequate supplemental light, their birds, which are primarily high production, long combed leghorns of one type or another, never skip a beat and keep laying all winter like nothing is going on. But also take that as meaning those growers are burning through their birds at light speed. Rarely will those birds be in production past 2 years of age. But even here, rarely is supplemental heat used. Rather they rely on heat from the birds (very high densities approaching 1 to 2 SF per bird….or less), and balance that with carefully controlled ventilation systems to reduce moisture levels to safe and comfortable levels. Virtually all of those buildings will be insulated and most will have supplemental heat, even if they rarely need to use it. If a person did want to provide supplemental heat, some source of RADIANT heat is the ONLY thing I would recommend. It would be folly to try to heat the air. Just as sunlight doesn't heat up space or even the winter air, a surface exposed to sunlight absorbs the radiation and does heat up PDQ. Birds will feel it too. The default heat option most think of is heat lamps, but those have some pretty severe drawbacks. One is the safety factor……when damaged, which happens, they can start a fire and burn your place down. Second is the light they produce, which screws up a chicken's biological clock. Remarkably, some turn these on and off, providing heat for a few hours, then turn them off? Even standard light bulbs will give off some heat, but again there is that issue off light and screwing up the clock. And lastly, the power factor. If your birds are dependent on heat from electric power to survive, they won't last long if the power goes off. Far better than any light producing heat lamp would be a solid form of reliant heat in the form of a radiant space heater. There are some designed for chicken houses and others use some form of electric heaters (and I would suggest ONLY electric heaters) such as the oil filled space heaters used in basements, garages, shops, etc. Anything that burns fuel, such as propane, kerosene, etc, also produce water vapor and CO2 as a byproducts. You want dry heat. But again, the NEED for heat is really, really rare if all else is done right. Think of heat as the option of very last resort. On the other hand, if you just can't stand it and insist on providing heat, and understand all the pros and cons, that is your choice. You won't hear any complaints or critique from me. It's just that you don't need to. BTW, a free and easy substitute for supplemental heat is sunlight. Lots of windows facing the cold winter sun will allow in a source of radiant heat to warm up the coop in the daytime, not to mention drying it out. The light also helps keep the birds active and feeding and in general healthy as well as happy. Light: It is well known that if you want your birds to continue laying full on all through the winter, they are going to need more daylight. 14 hours of light per 24 hour day is the magic number to keep them in full production. Commercial houses provide this type of light as do others who want or need the eggs and don't care all that much about longevity of their birds. That would be your choice….give them a break, let them rest and not stress them with winter laying or keep them going, knowing longevity will be reduced. Also, early started pullets may lay anyway, even in pretty severe conditions of cold. Even without supplemental heat and light. A secondary reason for adding supplemental winter lighting might be if you live so far north that the limited amount of daylight available to the birds is so short they simply don't have the time or ability to pile in enough fuel and water to survive cold temps to the next period of daylight. I don't know how far north that is, but probably north of the US / Canada border of the Midwest. Even locations as far north as 50 degrees latitude will still get at least 8 hours of daylight and lots of birds survive that with no heat or light, so the determining factor is probably a combination of available daylight plus cold temps, plus what you want from your birds. Of the two options (heat or light), most likely the one that would matter the most would be to provide supplemental light, ALWAYS at the start of the day, NEVER at the end. This would only be to extend the period of time the birds are off the roost and actively feeding and moving around and of course laying. You would never want to turn off the lights on the birds without a period of ramped down light as happens naturally at dusk. Otherwise, they would not be headed to or not on the roost when the lights go out. If you extend the day, do it in the early hours before dawn. Hours of light are hours of light. It need not be to your clock or sandwiched on the front AND back side of normal daylight. Put it all at the front to start the day out earlier. Let it end naturally at dusk. Of course some in the extreme cold of the far north will provide both heat and light, if for no other reason than they want to, either to comfort their birds, for the eggs, or both. No harm in that if that is their choice, and they understand all the issues, all the pros and cons and make that choice. Their birds and their choice. Summary: Feel free to chime in or ask questions about any of this. For those who successfully house birds in seriously frigid temps, with or without heat, with or without light, feel free to discuss your coops, provide photos, etc. as well as management of the coop. I'm curious to see what you use.