Chickens need a house?
Chickens will thrive in most any coop. It must protect them from the harsh winter winds, rain, predators,and be well ventilated. Well ventilated just means that there must be a good exchange of fresh air, to dry the droppings, and keep the ammonia smell down. If a pen is too tight, the ammonia from droppings can cause your birds to develop respiratory problems, and can blind them. Their pen needs to be cleaned as often as possible, ours are cleaned no less than once a week. A coop does not need to be insulated, but if it is, the insulation needs to be inside walls, otherwise chickens will pick it to shreds. In harsh winter climates, a heat lamp may be placed above the roosting area to prevent frostbite to the chickens' combs and wattles. It needs only to be used when temps drop below 15 degrees or so. Use your best judgement.
What do I build?
Coops are as varied as the chickens that live in them. Inside the coop should be a roosting area, nesting boxes, and a light source (window or light bulb). Without a light bulb in the coop, chickens will stop or slow down laying when daylight drops below 14 hours a day. It's nice to have electric at the coop for a million reasons, you'll be glad you put it in. Food, water, shell, and grit can also be kept inside, to keep dry.
How do I decide what to do?
Since this is such a vast area, what I'll suggest is what I did. Visit farms in your area. Look at some coops, and get ideas. Mix and match the ideas, and come up with something all your own. You don't need an elaborate set-up, just something to keep your birds safe and healthy. A truck cap with a closed in bottom, and a door in the back, will work as good as an overly elaborate chicken palace. It's all in what you want, and whether you'll enjoy crawling around cleaning a truck cap, or a nice spacious pen. Whatever you do, use common sense, so you can get in and clean. If the coop isn't very farmer-friendly, you're not going to want to get in there, and your chickens will suffer for it.
My last creation is like a carnival for chickens. It's an overdone coop that incorporates everything that I could think of. It is currently overpopulated, but it won't be for long. We'll be repopulating with new birds soon, and less of them. I'm building another coop to spread them out a little. It's easier to keep up an underpopulated coop than an overpopulated one!
How many chickens can I keep in my coop?
I'd suggest no less than 3 to 5 square feet per bird. 10 square feet per bird would be better. Don't keep more than 1 Rooster for every 10 hens. That is plenty of Rooster to take care of all the hens, for happy hens, and fertile eggs! More than that, and it invites the roosters to fight. We currently keep 3 heavy roosters on about 36 hens, and everything is going along just swimmingly.
Do they have to have a coop?
Not at all. They can stay in the barn, or machine shed, but they do make a mess. If they run free all the time, they will dig up all your plants, and gardens, and generally make a nuisance of themselves. Ours get turned loose in the evenings, just long enough to get some exercise, clean themselves, eat some grass, and destroy my strawberry beds. Come garden time, I will be building a chicken tractor so they can get out and root around, without wrecking the entire yard.
What about nesting boxes?
Nesting boxes can be placed anywhere in the coop. You can go with a fancy, prefabbed, galvanized steel egg nest, or use an old cola crate. We use both (bought the fancy ones at auction). You can witness either at The Chicken-O-Rama. They should be at least 18" square, and sit 24" off the floor. It's nice to close the tops in so that the birds can't roost on them because they'll make a poopy mess. They need to be lined on the bottom with nesting material. We use straw, a lot of people use wood shavings. Keeping good, clean nesting material is the best way to keep your eggs clean for hatching, or the table. If you plan to have one of your girls sit on eggs, you should have a nesting box on, or close to, the floor so she can get out with her peeps.
Roost poles should start at 24" above the floor, 12" for silkies. You can lay them all out like a bed, or stagger them to form a ladder, rising to the top of the coop.
Bed/side view o o o o o Ladder /side view o They can jump from one level to another
o when you arrange poles like this.
Poles should be made from 1" square lumber, with the top edges rounded off. Too small, or too round can cause the birds foot problems. Something slippery, like PVC pipe can cause problems. Black iron pipe will freeze their feet in the winter.
When constructing a bed of roost poles, it's nice to put hinges on the back to fold the roosting bed up to the wall for cleaning underneath. You should allow 1 square foot of roosting space for each bird. That means they should have1 linear foot of pole per bird, with the poles spaced on 1 foot centers. I'd suggest the bed style for harsh winter climates, as the birds can huddle for warmth.