The ark is an idea the Europeans came up with. It takes up as little space as necessary and is easy to move about the yard. The living quarters are upstairs for the chickens in my arks. I move them around from time to time, both the rabbits and the chickens.
The chicken ark was made to accomodate a few chickens. There is no wire bottom so they can scratch around wherever you put them.
The rabbits hutches were made from pallets and the chicken ark was made from recycled wood from a buddys fence he wanted removed.