Nothing special, just a kit barn from Lowes and some framing with some chicken wire. It was fairly economical and works for the few chickens we keep. I would've preferred a dirt floor, but the wood floor is holding up better than I thought it would. Try to clean it every couple months.
The garage blocks it from the butt-kickin' winds we get here in the hoosier state. We have a huge tree for shade in the summer. They have a fenced area (chain link and privacy fence) but usually free roam during the day and I always shut them up in the coop and completely enclosed area at night, or when we're going to be gone all day. We have lots of predators: weasels, coyotes, raccoons, skunks, possum, and hawks!
We have a few Golden Comets, who are laying like champs, and some older Cochin hens who are past their prime, but I just can't get rid of 'em 'cos they're so sweet. Our Cochin rooster was killed in the fall ('12) and I'm trying to find a replacement for him!!