Well, my coop is brand spanking new. Designed and built by my husband out of rescued materials and painted vibrant mint green with "oops" paint. What I wish is that he would have built it more like a shed or one of the cuter coops here on BYC so I could walk inside and it wouldn't be so plain. Thankfully, paint can cover a multitude of sins.
As it is, he built me a 5'x10'x3' box with a pitched roof on 3' legs and put doors on either end of the coop so I could clean or "do whatever you do in a coop". He made them swing sideways instead of lifting up which takes up a lot of room when they are open, but makes them easier for me for now.
In the summer I plan to have the doors lift up and out with chains to hold them open and add wire interior "screen" doors that swing open for access. That way my coop will have ventilation be secure and have "rain" shutters for the summer and still be easy to clean. I want the same arrangement for the pop door and windows, too.
I also want to add nest boxes to one side (haven't got any right now) and raise the roost. My husband put it 4" off the floor and it needs to be at least 2' higher. As it is, they try to roost on top of the babies' crate.
I have 2 chicks and a crippled bantam hen in a 2'x3'x4' dog crate inside the coop, so they are protected from the other birds. During the day, I like to leave the doors open to let in light and air and close them if it rains or gets too windy/cold (leaving the pop door open and a light on inside). I want to add a porch roof for the pop door and adjustable vents under the eaves by summer. Right now there are enough gaps at the tops of the large doors to let fresh air in without causing drafts, but once those doors are hinged to lift up, the gaps will be gone and I will need ventilation for the bad days. Since we are in Central Florida, I am not too concerned with the cold as I have 2 heat lamps I can put in if they need heat overnight. I am more worried about the heat, rain and mugginess of summer. My husband told me he left off the windows trying to keep our cockerels quiet. He figured the longer the coop interior stayed dark, the longer they would be quiet in the morning. Since it didn't work (thanks to those over the door air gaps), he will be silencing them permanently by inviting them to dinner. Then he will be installing the windows for me.