Anything that can keep a big chicken out could work. I improvised this a couple years ago : Once I make my permanent breeding area/grow-out area, I'm going to add one of those in, too. Now I have the cheap version (below) That's what I did, just a rectangular area of 3' chicken wire held up by those green garden stakes along one wall of the run. Roof is that green plastic 1" stuff, that hangs across some sticks.tied to the stakes. It's inside my run, so doesn't need to be sturdy. I lean one stake out at the bottom next to the wall to let the littles in & out.