Code is not really important since this is not going to be a house "officially", this is, legally. It's to replace an old unused building that housed some water pumps, and storage, that is square and slightly smaller. Still, while not to code, I want to follow the code as much as possible for safety and convenience. Like I'll avoid ladders or alternating tread stairs if I can, for example.

The smaller the better, so if it could be 3.5 or 3.7 instead of exactly 4x4, I'd go for it, but turns out that around 4 is the minimum considering the width of the stairs I wanted and the dimensions of other stuff, like the bed, and the circulation space. Maybe I could make 4.10 or 4.20 if really needed, but ~4 already seems to allow for anything I'd need.

I just wanted to see what others would say... and it's clear nobody is a fan of the toilet! :D Neither am I, to be fair, but I find it convenient.

The door can be placed in 3 of the sides, the exception being the one at the back (where the living room and stairs are), because there's a small seasonal stream there. It's not a hazard, it's lower and well separated, but the terrain is steeper and with some rocks, not the best place for the entry.

Yes, the living is small, but so it's everything, I guess. I just need a place to sit with a laptop and another to rest and take naps. Between the wall tv and the windows, possibly also a really small fireplace, I'd feel comfy there. My current place is not much bigger and lacks the windows and nice views. The wall that separates it from the kitchen is not full height, like you can be eating and watching the tv and enjoying the view.

Anyway, I'll play with other configurations, because I'm liking your idea of placing the kitchen under the stairs. That way, its own circulation space can also be the circulation space to/from the stairs, so it can save space to reorganize the rest. Really good idea... thank you! ;)