The easiest design is in the style of an A frame. With the upper portion on each end open for good ventilation which will help maintain a healthy flock. An A frame style is also easy to move, especially if wheels have been incorporated into the design at one end. This will make it possible for one person to pick up one end and move the ark with relative ease.
Another advantage of the ark design and ease of moving is that no one spot in your yard will be worn out or trampled by your flock. Most chicken will stay relatively close to their home. This will help control where they expel their waste. This is another reason to move the ark. Every area of your yard can have free fertilizer. The movement will also be appreciated by your chickens. With every move their supplemental source of protein will be replenished. These sources are the bugs and insects that live in your yard.
The last thing to consider about an ark is whether it will have a floor or not. If a floor is chosen then clean up will be easy by tilting the ark and hosing it down with a garden hose. If no floor is the pick then after each move, a rake should be used to clean up any bedding or other material that might have accumulated.
Chicken arks are a good choice for a small portable chicken coop that can be placed on almost every farm.