We are planning on building a 4X6 lean to coop in the next 2 weeks. The front will have a 2'X3' slider window above the nest boxes. I was thinking of putting vents on the back of the coop near the roofline that would go the length of the coop. The rear of the coop will face our vinyl stockade type fence so I don't have to worry about too much wind coming in. Should that be enough ventililation? We are in MA so our winters can be a bit cold but not too frigid. We would use the window for additional ventilation when the weather is milder.