Housing is an interesting thing when keeping chickens. Chickens are really not picky on where they lay their heads at night, but having a nice chicken house with roosts, feeders, and a laying box will make your life much easier. Making it attractive on the outside will also keep your neighbors from complaining.
We once lived up the street from a couple that had free range chickens. Now this was a town of less than 300 people and was very rural. But still these chickens roosted in the trees, on fences, wherever! There were huge piles of poop under where they roosted. The smell was gross and it looked terrible. All I can say is I'm glad that I didn't live right next door because chickens don't understand property lines and made frequent neighborly visits. Granted these people were in their 80's and couldn't keep up with the cleaning needed for free range chickens.
There are thousands of different chicken coops. From the ornate palaces to converted dog houses. All have their good points and bad points. It just depends on how much money you want to spend and the kind of setup that makes you happy
Our first chicken coop was made of straw bales stacked up in a square with a plywood top. We even put in a little window. Not the most pretty thing you would see but it worked fine for the chickens and kept predators out at night.
Now that we live in town and cant free range our birds we are using a small plywood building. We built a run for the chickens to go outside and exercise/dust themselves/get sun in. It works great and is easy to clean and take care of.
So things to consider if you want chickens in your backyard.
Chickens are tempting to many animals (and people) you will find in town. Especially dogs and raccoons! So having a secure place for them to sleep and roam is a good idea. A fenced run keeps them within safe bounds and keeps unwanted visitors at bay. One small dog can kill all your chickens in less than an hour. We use chain link for our run and buried chicken wire around the perimeter of the run after we found signs of digging under the fence. The way that works is the dog/raccoon/skunk starts digging at the fence line and then hits the wire hurting it claws. Suddenly chicken doesn't look so good! Some people use barbed wire in places with lots of roaming dogs and raccoons.
Also chickens are not what you call potty trained. They poop everywhere they go. So unless you are OK with finding chicken poop all over your yard, driveway, and walkways I suggest you have a run for them.
A cheaper way to make a nice looking chain link chicken run is to buy a used large chain link outside dog kennel on craigslist. You can find them for $100.00 and sometimes even free. Get the six foot high ones and then cover them with plywood or more chain link. It's cheaper than buying the materials from the hardware store and is easy to set up. Our plan is to get one soon, the run we made was just temporary.
Ease of Cleaning and Maintenance
If you are going to have a run that is not movable and a permanent building for your chickens make sure you can stand up in it. Otherwise when you have to clean it out or go into it for any reason your going to have to stoop over the whole time. Dirt floored or concrete are personal preferences. We've had both and while you can bleach concrete I don't care either way for the small amount of chickens I have. I would never do wood though because it absorbs smells, moisture, and will eventually rot.
There are lots of different options here. We use wood shavings because they absorb the poop better and smells nicer. Straw is cheaper but it is much messier. Cost is also an issue here so you have to go with whats cheap in your area. We use a deep litter system where we clean the coop twice a year. Then we put a couple of inches to start with wood shavings and add more as needed to keep it clean and smells down. This works great for us.
Food and Water
You have to feed your chickens, even if your allowing them to free range. You also must at all times provide water. If they have no or little water they will lay less eggs. You can buy feeders and waterers for your chickens. I recommend the automatic feeder and waterer myself. They keep the feed and water clean and prevent the chickens from wasting them. We have a 5 gallon waterer and a large automatic feeder that hangs from the roof. We only have to fill the water once a week and the feeder once every two weeks. This cuts way down on your labor every day. I just check them every day or so while collecting eggs (I have to fight with the children for this privilege) to make sure they aren't empty.
I cant imagine how much food I would end up throwing away if we didnt' have chickens. With 4 children there are many scraps everyday that go to the chickens. Old milk from sippy cups, fruit and veggie peelings, bread crusts, rejected meals, food that sat out too long. It all goes to those voracious bottomless pits. I NEVER throw out food. Everything from the kitchen that goes to the chickens except poultry products ( possible cross contamination here) that go to our dog. Chickens are like an amazing recycling program. The more food a chicken eats the more eggs it will lay. They also get grass clippings from our yard (we do NOT spray or treat our grass so be careful doing this), weeds from the garden, and any garden waste. They love it!
Egg Laying Box
It's a good idea to have a nesting box for your chickens. Otherwise they will lay on the ground or wherever they decide looks good. This will lead to you not knowing if an egg is "fresh" or "old", eggs too dirty for use, lost eggs, and possibly even to the chickens eating them which is a hard habit to break. You don't need anything fancy and can build it yourself or use a covered cat litter box picked up at a yard sale.
Shade, Dirt, and Sun
This would also be under shelter but is kind of special in its own way. All chickens like to sun themselves. This allows them to get vitamins they need. But they also need shade in the hottest times of year. Our chickens always go back into the chicken house during the hottest part of the day because there is no shade in the run (yet, working on that) at midday. If we had shade for them outside they would sit out in the shade. Chickens also need dirt to dust themselves with. It helps protect them from nasty bugs. So make sure to provide your chickens with somewhere to dust themselves.
Warmth and Light
In the winter if you have really cold winters, you will need to either make sure your chickens have shelter that will keep them from cold wind and weather or resign yourself to no eggs. The more energy a chicken expends on keeping warm the less eggs it will lay. If you use a small building/shelter and keep enough chickens in it they will huddle together and keep each other warm. Also sealing any drafts and having glass windows will help.
Light is another issue. Chickens need 12 hours of daylight or they slow or stop laying eggs. Every winter we put a heat lamp in our coop to provide the extra light and a little extra warmth for our chickens. That way we still get eggs even in the coldest winters. This winter was in the teens and under zero almost all season which is unheard of for around here!
Your going to want to control flies no matter what. Nothing is worse than ruining your outside time with flies everywhere. Not to mention your neighbors will really hate it. We use flytapes and also fly trap bags. These work very well. Some people lime the soil of their run and this keeps down smell and flies. I can't seem to find lime anywhere so go figure.