I guess I am bad at math! Do you add coop space plus run space to figure how large to make your pen? I plan on free ranging the birds and keeping 8 to 10 birds . How big does the coop need to be? The run? The only time I can imagine confining them to the coop/run would be when we vacation, for easy to whoever feeds them. I was thinking coop plus run being 8x10 or 10x10. We have a roofed 10x10 dog pen that has a dog box attached to the outside we made a few years ago. Thinking of doing something similar for the chickens. Thoughts? I have read posts and still am confused. sorry in advanced. Just want a happy healthy flock.