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I have watched these posts for quite a while. I live in the Arizona desert. We have lots of predators. People here, and some do have chickens, build a place to equal fort knox. It has to have a wire bottom. not chicken wire but heavier. Very small holes. even chicken wire muct be offset so the holes are smaller. the 1/2 inch wire mesh is good. Or it could be solid. I have one that is concrete, one that is an old wood that is pretty deteriorated. And one is just dirt. On the outside you must put either old tin or wire or maybe even railroad ties down so that it can't be dug into. That means flat on the outside for at least a foot or maybe even two. Predators don't know how to dig and go in for very far. It should be tight between the sides and the bottom.
Then you must put something heavier than chicken wire for your sides. Here they use very heavy chain link that is mine weight. Quite a bit heavier than 9 gauge. They use pipe and chain link for the sides and the gate. Also sometimes railroad ties for the posts. They bury the chain link down at least a foot. If there is wire for the top it should be heavy also. Also they must have shade and a place that is dry. So some of the roof must be solid and waterproof. We don't get snow or real cold but when it rains it can rain hard. It must be ventilated here so they don't get too hot. Most of it needs to be open, not solid.
We can't let them range. so you must have enough room in the house. I have approximately 10 X 10 and maybe five or six chickens tops in each. I do have a 12X36 slab with a tin shed that is 10X10 inside that. Outer fence, slab fenced, inside the shed. Three lines of defense. I do yet need to put the wire over the top of the run so the hawks and owls don't get them.
Remember your predator. Everything from bears, hawks, owls, bobcats, skunks, racoons, to snakes. Small holes, you don't want to find a rattlesnake in your nest box or coiled around your waterer. So over your heavy fencing you must put small preferably 1/2 inch wire. It must go all the way up, they climb.
I once visited a ranch and they had chickens, chain link
My mother had 1/2 inch wire all the way up, no holes up high either. That coop was inside a chain link fence.
This is a bit random but I tried to include it all, remember the shed must be shaded. too hot if it sits in the sun. If it does use shade cloth.
Hope this helps, you can build it safe.