Here is the Coop. I finished it in early April. The frame is re-claimed pressure treated two by fours. The roof is plywood the whole top is vented. Vinyl coated welded wire. All the fasteners are outdoor deck screws. the whole thing got 2 coats primer, 2 coats fence paint, and 2 hard coats shellack. (its humid here next to the swamp/river. The bottom foot print is twelve by 6 feet. The frame will not rest on the ground, it will rest on 10in "hardie board" siding
Here is the whole story of my BYC project.