Need input.....

This is the front of my coop. This was taken in the afternoon and it faces the South. Since they don't have much wind break I'm thinking I will need to add some clear sheeting during the winter. Here in Alabama though we have fairly mild Winters. I am also planning an addition to my coop and run on the west side. Not going to make the coop as tall for this one. though. Any suggestions are appreciated.

This is the back there are 2 doors. The one on top is where I gather eggs well I will when I get eggs. The one bottom is for cleaning. It works pretty well to get stuff off the floor but we didn't think through as you can see from the next pic of the inside. We have too mainy flat surfaces. I'm thinking we wll cut a door on one of the sides so I can accessthose flat surfaces better to clean. The pic below shows how the door opens to gather eggs.

All in all the coop and pen look good. You can add some extra wood put in at an angle in some of the flat areas to keep the chickens from being able to hang out and mess up the area. Suggestion for installing wind break on the side where the wind comes in in your area for this winter. Simple as some plywood or plastic in that windy corner or wrap the whole lower half of the bottom, your choice . As long as the chickens can keep their feathers from being ruffled by the wind they can tolerated the cold real well. What kind of roosting area do you have inside the coop?

You've got the coop facing the right direction. All your really cold wind is going to come from the north in central Alabama, so you might not need any additional wind break for the run area. However, where the nesting boxes are it looks like the boards are spaced far enough apart that daylight gets through. That means that wall is going to be drafty in the winter. I would either place some battens over the gaps between the boards or find some other way to plug up those holes so the wind won't get in. I've seen pictures on BYC of chickens walking around in snow, so I wouldn't worry about the run area. They can go in the coop if it is too cold and windy.
I'm guessing the flat surfaces you are talking about is the area over the nesting boxes. Like the other poster said, put wood or something at a steep angle leaned against the wall and over that area so the chickens can't stand up there. Corrugated metal works good because they can't get a grip on it. Any slick surface at a steep angle will keep them off of it.
What is the purpose of your addition? More space for you or the chickens?