More practical advice...if you live in a cold area or just don't want to have to go out to open the coop door immediately in the morning, install a vertical sliding coop door with an eye-screw in the top and set a pulley in a tree or homemade frame above the door. Tie the rope to the eye, run it through the pulley, and then to your back door (or window...any opening will work.) When you need to open the coop you simply crack the door or window and pull the rope, lifting the coop door.
Ok, so I'm only in Virginia, but I'm from Louisiana, so I think this is cold. I'm going to see if my husband will try this! Great idea.