I quite like the Playhouse Coop design shown on the BYC site. Has anybody built this design? My husband likes the design, but would like a 10' run. We will probably have 4-5 chickens (I will let them out in the yard as much as possible). I would like to have a window that opens with wire cover and make a sliding poop tray. I'd thought about having a slat board idea over the sliding poop tray, similar in concept to the Eglu. I do wish to minimize the chickens stepping in poop, while making the coop easy to clean. Is there sufficient ventilation for wintering with 4-5 birds? It appears that the vent is along the roofline interior.