I've helped my cousin build a coop and run where we were short on supplies and funds so we made the run short, maybe 3ft tall. We just used a 4X4 in the middle and for the frame of the run (run was about 6' wide and 10' long all together) and that was the main beam, fixed the top with 2 parts wire 2 parts aluminum on 4 frames, and hinged them all to the 4 X 4...So to clean it you did one side at a time, flipped up two frames and raked and shoveled it. closed the frames (windows/doors/panels whatever you want to call them) and latch them closed, then move to the otherside. worked great, saved money and material, and was very cute. it didn't move at all, we built a second run just like the first attaching to the opposite side of the coop for added run, so they wound up having 6' X10' on either side so thats what 60 sq foot X 2 = 120 sq ft?
I'm one of them people I dont like to do the same thing twice, or I like to try new things or else I would build one just like that for my next coop (i'm working on one with a 4.5' PVC run and its moveable though) later in the summer.