Hello all. First winter with chickens. I built a 6x12 coop. 4x6 of it is henhouse the other 8x6 is open run. I'm starting to add plastic for winter. Iowa can get cold. I've seen people leaving top space open for cross ventilation. I was planning to leave 4 inches up top open on the 3 open sides. Is this too much? Feedback is appreciated. Thanks all
