My friend used one with the aluminum top and wire about 3 feet up right? is that what you are talking about?? it worked really well and he had the coop attached to that BUT he had the wire mesh from bottom to the top (bottom of the aluminum top) and had chicken wire only about 2 feet up, he should have put chicken wire on the entire wire mesh and then buried some, he didn't and lost his chickens. I was looking at his yesterday and with the 8x8 or maybe even a 10x10 coop attached was a really nice chicken "run" -not a coop and if he would have put the chicken wire all the way up the mesh and buried some, he would not have lost his chickens. I would love to take his whole set up as he is not currently using it now that he lost his chickens but it would be huge to move and him and my hubby are in trucking LOL!!
Again, the top of the grain bin with wire mesh about 3 feet or more under the aluminum roof is great as a "run" but not a coop. Good luck let me know if you need, I'd be happy to send pic's over of his set up.