My first Chicken coop in the works, it is a 4'x8' floorplan built on 4x4 posts with standard code walls "2x4" studs, I used fencing materials to cut costs and aid in creativity, both cedar and treated are used out side, to keep it rain proof here in the Pacific NW I covered the studs in black jack in certain areas.
The Chicken door was installed on heavy drawer slides.