My neighbor has a well-deserved reputation for quality construction projects. So when he said he and his son were "throwing together" a chicken coop a few months ago, I already knew that his thrown together shelter would end up looking better than any I might build, no matter how carefully. I was right.
The south-facing window on most chicken coops which lets in that precious winter sun also turns the coop into a greenhouse if you're not careful. Make sure to vent as necessary, but there's no substitute for a patch of ground for the birds to roam. Pecking out grain and bugs from the ground give the animals a workout while keeping their food supply diverse. Chickens will eat most anything from the compost bucket (or most anything, period). A healthy diet will result in healthier chickens, which means better eggs and/or meat according to your tastes.
Another friendly household with chickens I know used some nice found branches for accents like door handles for their coop. With local laws lenient on fowl, many city-dwellers in Lansing are finding that with a simple shelter and a little consistent care, keeping chickens is a productive delight.
Don't forget that a little shade goes a long way to make animals comfortable on a hot day. No need for AC in the coop.