I wanted my girls to get more than what I can supply in the pen. Free range is not an option with the predators and loose dogs in the neighborhood. I decided to build a tractor which could handle 6 chickens. I currently have 12, so they get every other day in the tractor. I looked all over at different designs and fell in love with the "A" frame design. I is 4' wide and 10' long. The enclosed area is 2'. It cost $150 and 2 days to build.