If your birds will roost in the run, I would cover the whole run with 1/2 in hardware cloth to keep out the racoon hands, rats, mice, weasels, squirrels etc. I leave my pop door open to my run but they still roost in the coop anyway. If you click on my byc page you can see my setup. The window is in upside down and inside out so I can lower and raise it from the outside and the open window part is higher up. The inside is covered with hardware cloth. Your ventilation looks great for the winter but in the summer, if it is hot they need more circulation I believe. Cute coop!