alt Hacker NewsIt doesn't look dense urban, things are very often more relaxed in semi rural areas and low density zones; further he has existing underground structures that I would guess have already been approved.
If I had to, I'd bet he's had a conversation with a local planner and had a nod and a wink already.
It also helps that he has a fairly popular YouTube channel. I expect the locals are aware of that and so they're even less likely to do something because they know that there will be a public outcry.