Before we talk about the backyard chicken coop, let's talk about chickens first. There are other requirements other than your desire to have chickens in your backyard.
Are you zoned for chickens? If you don't know that answer, call your city office, and make sure you are zoned for keeping chickens. You do not want to go to all of the time, work, and possible expense of building a chicken coop, to have a neighbor squeal on you.
Do you have enough space for them? If you have a postage-size backyard, you probably do not have enough room. Chickens, generally speaking require spacing of 1.5-2 square feet/bird for the chicken coop, and 8-10 square feet/bird for their outside protected pen area. Chickens are very busy and active as a rule, and if they are too confined many problems may follow. You probably don't want your chickens too close to your home or back patio for obvious reasons.
Do you have a game plan as to where you are going to keep your chickens? Do you have an old shed or stand alone building that can be modified into a chicken coop? Will it be safe from rusty nails or exposure to anything that would harm them. Are you planning on building a custom chicken coop? You must provide shelter for them so they are protected from weather and predators. Make sure your chicken coop is large enough for you to get in and out of easily for interacting with your hens, egg collection, and cleaning.
Are you responsible to care, feed, manage your hen flock faithfully everyday? Chickens are living creatures, very sweet, and very sensitive. They require everyday attention, just like your dog or cat. Caring for chickens are wonderful lessons for children. They learn lessons about responsibility, discipline, friendship, raising your own food, rewards, and more. Do you have a close neighbor or relative who can watch and care for your chickens when you are out of town?
Do you own a dog now, that is a terror for the neighborhood cats? Or do you have big problems with coyotes on your property? If you have known existing dangers, it is probably not wise to introduce chickens to this equation.
Will having chickens break your bank? Young chicks and pullets are very reasonable to purchase. Most of your expensive will come from purchasing their ongoing feed and bedding. Are you planning on building your chicken coop from scratch...do you have the money for that initial investment? Heaven forbid, but there might be times when your chickens need a vet. Can you afford a vet for your chickens?
Are chickens easy to care for? They can be quite independent, but I find they enjoy human interaction and bond easily with people who care for them. They can be petted and picked up, but don't do well with roughness. They enjoy treats, beside their laying mash, such as fresh cantaloupe, strawberry hulls, fresh chard, lettuce, etc. Remember, what a chicken eats, determines the taste of their eggs. Never feed chickens any poisonous plants, or anything with strong flavors.
Chickens give back. Chickens have different personalities, and even sounds, which make them all unique. They are a lot of fun to watch, and interact with. They are always busy, and on the go. You will soon experience eggs, like you have never tasted before. Their manure droppings can become a valuable addition to your compost pile, and ultimately your garden. Chickens require little, but yet quickly become a part of your life.