These are photos of my coop-tractor. It houses 3 barred rock and 3 buff orpingtons, all hens. As I could not find a design plan, I made it up as I went along. I think I researched too much. The wheels make it pretty easy to move--I always move it with the girls upstairs. The large screen door is to allow for the open front coop camp and the large area is to be able to deal with the Illinois winters. I have a sliding hatch door to keep out predators that might get underneath during the night. I think moving them every day helps to keep that under control. Their food and water is always in the coop and only greens go on the ground for a treat. I keep a dust bath upstairs so they don't need to dig too much (ha!) There's room for storage over the three nests. The entire bottom of the coop is a tray that comes out.