My chicken coop is about 10 ft x 20 ft on the outside with a hen house inside the barn, I had a pair of buf orpingtons that would never go into the hen house. Now my 6 Plymouths always go in at night. It just where they feel comfortable, maybe a good storm will get them into the covered area. Just remember meowzer you don't want them sleeping in the nesting boxes and they should have some roosting areas, I just use 2x2 lumber.