Building a chicken coop for a small flock of hens is really not that complicated. And chicken housing comes in many shapes, sizes, and designs. Most people should probably start with building a chicken coop that's very simple at first.
My boyfriend made this chicken coop by building onto a rabbit hutch and was able to transform it into a pretty functional chicken house. However, he spent way more money than he should have, because we ended up giving the chickens away within a year.
A chicken tractor coop will probably be the most ideal for people who have enough land. This design can make it much easier on you and building a chicken coop that moves can help you to manage weeds and bugs on your property.
Start with a small chicken coop at first, because you may change your mind about wanting to raise chickens. And if you really like raising chickens, then you can expand to a larger chicken coop down the line.
A small chicken house is great for people that just want to get started with raising a few chickens, but don't want to spend a lot of money on an elaborate chicken house.
You can just throw something together with what you have lying around your property or purchase a small chicken house at a chicken feed store or online.
Sometimes people are giving them away or selling them for a bargain, so look in your local paper or on Craig's list.
Worst case scenario, you can use your dog cage as a temporary urban chicken coop. Of course, it will depend on the size of your dog's cage as to how many chickens will comfortably fit.
Just be sure to add a perch or two for your chickens to roost on at night and a nest for laying eggs. Chickens must always have water to drink and food to eat. And be sure that you give your chickens enough space to forage and provide them with a chicken run if possible.