That is not a shack. I’ve lived in a couple of old WWII houses that were about 700 sq ft. One, hubby always laughed about he couldn’t turn around too fast in the tiny bathroom or he’d end up having se... well, you know. It was much easier to keep clean but I want a kitchen where I can at least get a good back swing on a skillet.
I currently live in 900 sq ft not counting the basement or the large enclosed porch or the detached garage. 3 bedroom but one of the bedrooms is currently my laundry room. I live alone and it would be a little tough for me to downsize. I happen to know there was a family of seven in my house before I was in it and that was before they added on to it. It was originally about 500 sq foot.
I once dated a girl that lived in a one bedroom quonset hut with a finished basement and a good sized deck and large detached storage shed. No garage. She lived alone. That was a nice little house. Plenty of room for one person with all the modern luxuries.