You do realize that there is no need to be so rude, right? Coop winterization wasn’t my question anyway.
I have raised chickens for almost 10 years, and still have ladies from my original flock, who still lay eggs, btw. My coop is a large shed with vinyl siding and has been winterized. I believe it does hold heat quite well. My theory about having enough hens in a large space contributing to their overall comfort and warmth in winter might be wrong but it makes me feel better and seems to have worked well when it’s 20 below. I haven’t lost a hen in winter yet, so I assume I’m doing the right things. I hope you have a nice day!