I'm in SE Arizona. My coop is in an adobe barn that never gets cool. I want to build a coop in the run (45'x45') just to house the chickens in the heat of the summer. It will be insulated well with reflective paint. I do not need to get into the coop, just enough height for the chickens to roost. The wire floor will be two feet off the ground to allow for ventilation and raking under it. How high should the actual box be? I do not need to have nest boxes because they will still have access to the main coop. I have Easter Eggers and barred rocks.