Sorry to be slow, but I still don't understand. I do not see anything that looks like a dry coop to me, so I am not sure what it is you are calling the coop. Perhaps you could label the picture to explain?You see there is a coop at the back that’s the coop!!
A coop is a building (a little house) that is dry and includes a roost (which is often a 2x4 piece of wood as shown by @AntiqueB in the picture above) as well as a nest box.