A friend has that same problem, so she had a small cute doggy/bird house type made for her kitties right outside the back door. It is a small replica of the big house, painted the same. It is modern inside in that it has a long hallway, and at the back of the hallway is a door into the "bedroom" which has a window in the front. The roof lifts off for cleaning and the flooring has a big pillow. The outside cats are real comfortable even in harsh weather.