I have never run throughout the house as a workout.
Some treadmill days here and there, although not often.
High school days in Northern Illinois meant a few days a year running in the hallways when we could not get to the indoor track at the sister high school 4 miles away (e.g., in a blizzard). Actually very slippery, and a recipe for slow running.
I have also run in a multi-level parking garage. This is actually a fairly good solution on days where snow and ice are not adequately plowed or treated. I felt odd doing it, but read back in the 90's where Joe LeMay (a marathoner) did it, and said, heck, if it works for him, it works for me.
I was always inclined to speed and intensity over mileage, so none of the indoor solutions ever worked out that great. But it is what makes running interesting.