I have an 8' x 16' Hoop Coop. 4" x 4" x 16' baseboards on the sides and 2" x 4" x 8' baseboards on the ends. These are setting on concrete blocks or concrete end caps (I used them to level on a slope) which are setting on buried rabbit fencing. The length of the coop, like blucoondawg, is arched cattle panels. I covered my panels in hardware cloth (because I live rural and we have coons, coyotes, etc and while I've all ready shot a lot of them - there's always more to go around). I used t1-11 plywood to make my end cap walls. The front half is completely open run and the rear has an elevated coop (~ 2' off the ground so they can have ground access to the entire thing, essentially having an 8' x 16' run.
The coop is basically the entire rear 8' x 8' but is really around 8' x 6' because I made straight side walls on the coop instead of curved walls so I had to come in about a a foot on each side to fit inside the hoop walls. I basically made a frame that attached to the rear framed plywood and my center post and added plywood walls. I didn't build a roof for the coop (since I have a heavy duty trucker's tarp (TSC) covering the rear of the entire hoop coop. I just covered the top of the coop with hardware cloth for ventilation. I'll add photos soon but basically it's a big box without a roof inside an 8 x 16 hoop coop. A lot of people just stack straw bales or such to act as a windbreak and that was my original plan as well, but 1.) I had a lot of extra lumber laying around, & 2.) I'm one of those sissy types that worry about my birds so wanted to give them another level of security by adding the coop to help against the elements and predation. I think that the hay/straw/whatever windbreaks are perfectly fine and would be using it if I didn't have a ton of extra lumber laying around.