This is mine, inside the run but not the coop. There is food and water in there, so something is in there in this shot, though the chicks belong to the light colored hen. It's in the driest, most protected spot in the whole run, including inside the coop. The picture may only show a shadow, but it is under a roof and protected on the other three sides from wind. It's 7'x3'. I've had as many as 18 small chicks in there, but I integrate starting at 3 weeks, so crowding isn't an issue. By six weeks, I usually cut them off and they have to deal with the flock. I haven't had any problems with that schedule. The bricks block off a 3"x4" opening, there's also one at the other end so they can come and go and escape the adults. I might make the openings a shade smaller if were to do it again because adolescent birds sometimes do learn that they can sneak in and access food nobody else can when the doors are open. Food and water in there for them and a heat plate. I have brooded chicks February-December this way, though nowadays I stick to March-October. Sometimes there are small pallets, bricks, firewood, whatever to keep food and water clean and give the chicks some things to clamber around on and hide under if they choose. The top is solid so the adults can get up there and it's still protected if they poop on it. Our goats even climb up there when they're allowed and it holds. We used chicken wire because it is less expensive and this is already inside a run, behind a physical fence with netting on top and behind an electric fence as well. I chose to make the back solid because I've noticed chickens feel really uncomfortable in a total fishbowl where they can be seen from all sides. Two things I would change: 1) I'm 5'9" and this is 3' feet tall. The top levers open and I have to reach in to grab chicks or clean. It's a little too tall to do so comfortably. It's very heavy and I couldn't lift it alone. That makes climbing into it easy enough when I need to, but I would make mine shorter next time. The chickens don't care about the extra height. 2) I can let chicks out, but when I use it as a brooding pen for a hen or to isolate anyone for whatever reason, I have to lift them out, there is no adult chicken sized door and I wish there were.
