I don't often recommend Belgians, but if you are going to consider them at all during your research, a low-drive Belgian may fit your situation. They are very active outside, but couch potatoes indoors. They are good being left alone provided they are left with some sort of stimulation, but if you want to keep it outside during the day, I'd recommend one from American lines rather than European, as European Belgians are quite the alert barkers. You would have to make sure it came from a good breeder though, and the breeder should tell you what type of drive it is, as the more drive, the more difficult the dog is. Low drive Belgians can fit almost any situation, they adapt very well.