For your weather, I would just leave it open year round with the HC backer.Couple questions first when you say windows I assume you mean just cut them out, not actual windows, I like the half inch hardware cloth idea as a window, just wanted to confirm we are on the same page
Second is there a "good height" for the roost in the coop? Sometimes the girls seem to like the lower levels and other times fly to the highest spot they can get to. Thanks for the input Never really thought about putting a window above the door as suggested. Thanks again
Your coop isn't that tall so I would just position it as shown just above the nest box and pop door and centered on the wall. That way they will have room to jump up on the roost from either side.