Im confused with the square footage for the chickens. I am getting 6 chicks in April and might get a few more than that. I think I would max out at 12-15 chickens but I'm allowed up to 20. Do in make my coop for 20 chickens? Would it be too big for only 6 chickens to start? How big should I make it? The area it's going in doesn't interfere with my yard. They will be in coop/run most of the day and free range a few hours while I'm outside with them. How big should the run be?