Can we talk about being frugal with SPACE?

So, I watched a documentary called "A Cluttered Life" on youtube while waiting for my coworker to be ready to do the things today, and I was surprised that some of it really hit home.

I don't have an overstuffed fridge, and I don't have toys in triplicate.. I don't have anything in triplicate like shown in the documentary. But when they showed that people don't use their homes and are essentially paying a lot of money for space (heating, cooling, cleaning time costs...) that really made me rethink two very badly under-utilized spaces in my home. One is my 'living room' in which very little living happens. The other is my breakfast nook which contains some outdoor equipment, a dismantled bike, mail and laundry. I've pretty much always had this problem where I have a living room, and I don't use it.

I guess I hadn't considered space something to be frugal about, but now I feel very anxious to make that useful space. Or at least, not a drain on me. I can't move -- I own, but I'm curious about how others have been frugal with SPACE, specifically, extra space.