Back in 2003, Steve Sauer found a basement space, ostensibly to store his stuff. He ended up converting it in to the tiniest apartment I've ever seen:
It's the farthest thing from homesteading, but in terms of efficiency, he's got it going on! He's got two beds, bathroom with
shower, soaking tub,
video lounge, nice kitchen (albeit without much storage), dining room for 6, "cafe" space for 2 by the window, storage for multiple bikes, walk in closet, standing desk.
More nice photos
here.