But on the topic of a non-engineer building a tunnel, there is also Colin Furze on Youtube [0]. Building a tunnel under his house to connect his 'bunker', workshop, home and future udnerground garage.
[0] https://www.youtube.com/watch?v=YOelRv7fMxY&list=PLGjbAdaOBL...
The rock removal isn't much of an issue if you, say, ring your local council and ask where they stockpile material. Our council has several acres with piles of sand, clay, rock, mixed, etc. that gets dumped after trenching, levelling, et al. jobs and reused when fill is needed.
"Good" rock (for some value of) can even fetch a bit of cash from garden centres and elsewhere.
Also, she’s using the good rock to build a new exterior wall in front of her current walls, with a goal of turning it into a castle-like facade. Again, no permits.
karma++ this lady!
