This is our Hühnerstall - it was my 2011 Summer Project that keeps on growing. Yes, even to this day I look for ways to improve it. I will try to place pictures from the inside as time permits. New goals - improve feeding and watering techniques.
It started out as an elevated A Frame - too hot and small for chickens (gave "cooped up" a new meaning). So, I decided to give it some height a week after it was "finished." I raised it, put paneling on it, and my eldest son painted it.
Please note, there are four screened windows that allows much needed summer breeze. I have placed tracks inside which allow me to secure plexi-glass to stop the cold air and allow sunlight to help heat. I have a large door on the west side which allows easy egg retrieval and cleaning. It is tall on the inside - I have four roosting boxes (the chickens only use one right now) - but they are key to a second floor where the larger hens sleep.
The fencing - the chicken are complete access to the backyard - except I'm keeping them out of my garden, they are pepper leaf and tomato eating fools. Prior to them having complete access they were secured from my Shepard/Lab Mix, who recently died. There are bending in the wires from her, but if the double fencing and reinforced edges kept her out, they'll keep any animal in our area out. The fencing also goes about 12" underneath the coop. Just in case, there is an inside latch in the upper portion - this is in addition to the outside security measures
Last comment - yes, there is electricity (installed to code) - running to the coop. It supplies a heat lamp to help prevent the water from freezing and a small fan to help circulate the air - 100 plus days are stressful.