I'm looking forward to seeing this done. I'm planning similar for my summer coop (they winter in the barn, and free ranging did not work last summer). I plan to bring a lean-to off the side of our driveshed, I'm thinking 10' wide by 12', steel angled roof and one side steel to create a dry, sheltered corner for roosts and boxes, then the other two sides open air and hardware cloth for predators. I want to try raising a few meat rabbits this summer so my thinking is that I would put their cages inside the coop for security. I have a nice indoor coop in the barn for winter, so this will be their 'cottage' I guess. I'm still in design phase, so looking for ideas!