I used to have a male Lab/Shepherd mix, he used to share an outdoor kennel with a female bird dog. She used to tear him up so he decided to take up residence on the top of his house for everything: food, water, sleep. When he got old enough and we built a second kennel, he kept up this habit for years. He'd sleep up there during the day (unless it was raining or snowing) and during the night he'd sleep in house. He kept this up for a decade before old age started to get the best of him.