It depends on what kind of dog you have!! For smaller dogs who NEED to be inside, I think it's essential that they be indoor. If they're large dogs, and want to be outside, need excercise, destroy the house, etc...I think they should be outdoor. Blaze is a mostly outdoor dog since my parents don't want to clean house all the time, and have him scratch the floor with his toenails. Blaze also HATES being cooped up, so whenever he comes inside, he looks for trouble and feels cooped up, so being outside is a good thing for him. With ALLL that energy, he'd ruin the entire house being the dog he is!! (ha) Still, I always bring him in during bad weather, etc. He's just a natural outdoor dog!