This book seems to make a lot of sense actually. I'm currently digging a 3x4x2m hole in the country. Progress is about 5cm/2hr of work/day, but recently I've hit clay or some similar material which is hard to scrap trough. Further digging will be needed for external stuff, but for now I need to focus on the main part before it gets too cold. I now live in a tent and it's prety comfy, weather is still summery and nice. I plan to live in my test underground house for a winter or two and then if it's livable get more land which is closer to city where I also have a place to stay and many friendo's as country is 100km away rn and that a bit exhausting on a bike. Any of you have interest in cheap diy underground living? pics from about half a month ago