What a GREAT looking coop! I love all the light your coop has. I agree that the weight of the windows/gravity and the relationship to the hinges you chose are why they're not closing by themselves. A simple solution might be to just put a stopper at the bottom of the windows. You could just use a piece of wood on a swivel and turn it to keep the windows closed when you want. Love the 'chunnel' too! I know when we moved our girls out to their new coop this last Fall, we did have to shooo them in and then close them in for a few nights for them to get the idea. Now we'll turn around early at dusk and the've put themselves to bed and it's time for us to go up and close up the coop.