Why not use plastic corrugated panels? Fiberglass? The come in varieties of tint and colors, even clear. I have some I paid about $20 for a 30" by 8' sheet.
I use them as vertical wall sections inside the coop to keep the drafts away from the roosts. (My roof is corrugated metal, but the coop has so much air in it it does not seem to be a problem despite a few leaks.) I confess, my backyard is my great grandfather's barnyard, and my coop is in portion of the old barn. I keep 86 chickens in there, about 500 square feet, and I leave all the doors open most of the time. One door on the south side was as big as a single garage door, and is gone now. I have left a 250 W red lamp on in there in case a few are cold, but not many seem to make it a point to sit or roost under it, so I am guessing they are warm enough. It has got down to 9 degrees F this year, but we are in our "indian summer" now.
They were locked out of the coop one evening and I had to move the pile in, they were in a PILE, and it was really warm in there, so they are capable of taking care of themselves. (even the obstinate roos cuddled up....)
I think the main point I stick with is unless you live in a VERY cold climate, keep the birds dry and away from feather ruffling wind and drafts.
Birds that can't fly. Wha????