I'm new to all of this and am sitting around trying to design a chicken tractor in my head. I'm just wondering how much vertical space should be in the coop/nesting box section of the tractor. Is 1 1/2 feet enough? I want to design the tractor to fit over my box vegetable beds, which puts it at 3ft x 8ft. I was going to try to keep it down to about 2 feet high. Any suggestions on how to incorporate a "coop" area into this, without taking away too much running space?