to a 4x4 coop, can the height of the added on part be just a couple of feet high? or does it really need to be as high as the rest of it? I thought perhaps I could cut out a rectangle and add a box of some sort to the outside that would give them extra room... problem is I have a 4x4 coop right? well I sorta have more than 4 chickens right now. LOL! I'd maybe want to keep 5?? yeah? would this work? or is it just silly?