How Much Do We Really Need?

I'm reading a novel that has a scene in it with a group of anchoresses, vowed women who lived during the middle ages dedicated to a life of prayer and contemplation in the solitude of a small cell usually attached to the church. The cell had three windows: one opened into the church so they could receive Communion, one was for contact with her assistant, and the third was for people to come and request prayers, advice, etc. When I saw the video below I thought of the life of the anchoresses.

Obviously the tiny home below would not be suitable for a large family, but how much do we actually need? Most of us are drowning in stuff! I know my husband and I talk about this often because we live in a large colonial that is only full in the summer when our children and their families come to visit. Most of the time we rattle around in it using only a fraction of its space. I don't think I'd like to live in 320 square feet like the family in the video, but many people in the third world would consider their house a mansion!