I say this as someone who does a great deal of unprofessional carpentry, electrical work, mechanical repair, excavation, plumbing, etc. for myself and for family members. I would never have gone willingly into that hole. I certainly would never have asked anyone else to do so. No unexploited worker would have done this work.
- an underground multi-level beach hut: https://youtu.be/AojTrc_UMaM
- apocalypse bunker under his shed: https://youtu.be/KO25JYAaJC0
Property owners should be able to do their own work on their own property or act as their own general contractors. Disallowing that is right up there with gated communities that tell you exactly how tall your grass should be but that's the only way to prevent this kind of thing. I don't think everone's (already highly limited) right do what they want on their own property should be further curtailed because of one bad actor.
Yes that would have been too expensive for Beckwitt, and he would have never been able to get permits for it. That would have been society functioning correctly.