There is so much wrong about my hen house..... there is a large-ish window right at roost height that the hens don't like to sleep in front of. And although it does close from the outside, it's hinged at the bottom. It's hard for me to close due its weight and height, especially in wind and rain (I'm old, weak and short, but I manage, but it's always like something on America's Funniest, lol!). It's also the only real ventilation in the building besides the door, but the window faces west and the door north. It gets stifling in there in the summer and wet and bitter in winter.
I've got my eye on a nice pre-owned shed, maybe 12x18 or 18x24 I can have modified to better specs. Am paying close attention to y'all's recommendations and modifications, and doing some pondering and figuring. Chicken math! I'll keep the original for a quarantine tank or a brooder, maybe.