The cat house is completely open, so it is not heated or cooled. If its too hot we make them come in.
The house is connected to our living room. The cat door we got was made especially for hot and cold climates to reduce the amount of heat exchange. Really the only place there are any air leaks is around the door. When the cat door is closed, there is very, very little air that leaks in or out of the house. The only time air really moves, is when the door is open (aka a cat is going out or coming in).
Location wise, it is on the northwest side of our house and is shaded most of the day.