I wanted to go with a hut just so I could build it myself. I've had lots of experience concreting and have put on a few roofs in my time. The actual timberwork looks piss easy if you follow a plan. And because I planned on living without electricity and plumbing, the hard shit isn't there. The only cunty part would be installing a coal range or a wood burning stove, and also a window. But I'm sure I could achieve it.
I've been going through the government regulations and it looks like there's a bit of red tape. Even a structure at under 5m2 requires a building certificate, code of compliance and inspections if it's the main building on a property. And also fire alarms are required for all new builds, which means I have to install electricity even though I don't want it. I didn't see anything on insulation, but there's zero doubt that I'd have to pink batt the thing. The only way I can get around it is if it's a secondary build on a property with a house already on it, then I can just free build something under 10m2 and live in it. I mean, it's not like I couldn't do it, but like, that's a few thousand dollars I'm pissing down the drain for a structure that will cost me less than $8,000 to build.
But you're right, a trailer is looking like the best bet. There's something comfy about living in a wooden hut with a small wood burning stove, down south in the middle of nowhere with your veges and sausages cooking. Living in a trailer doesn't quite get me that Kaczynski experience.