Hello! Hmm, chicken coop... you know chickens like to perch at different heights according to their pecking order. Then it becomes very dirty "pooped" in a chicken coop, so you need to be able to go in there and clean up... you need more height than 1m. I suggest something easy to clean on the inside, like plywood formwork. You should frame with cc60, so you need studs with that spacing; the boards are 1.2m, so they will sit on 3 studs. I suggest starting from cc60 when you determine the size of the coop. If you take 1.5 boards, the inside measurement will be 1.8m. The chicken coops I've seen have a poured floor so you can rake and also rinse off the floor. I don't think the chicken coop you describe will work.