I leave alot of venting , and then cover the coop with greenhouse plastic in the winter . If you notice my walls are open on the ends along openings on 3 sides , but i left 1 wall completey solid so i can turn it into the wind in the event of cold night or severe weather .
Built from pallets and lumber scraps lying around , tree mesh i found at ollies for 2.99, and plastic trimming from my greenhouse .
my future chicken Tractor , picked it up for $70