I do my own building, construction and renovation … did some commercial work but never enough to want to do it for a living … I know enough to do my own but not enough to call myself a pro.

From what I’ve learned about underground building is that it is very dangerous and a health hazard. You have to constantly monitor and create safety measures for gases and oxygen levels. Even with the best setups … actually with super sealed setups … it can be very dangerous without active monitoring. Carbon dioxide, monoxide, and many gases will naturally want to drift to lower levels and displace oxygen which wants to move up … if you happen to be unlucky to have a generator or car running next to your exit/entry hole … your underground space quickly loses oxygen and without monitoring equipment or alarms, you just get dizzy, fall asleep and die … very gentle death because you will never know what happened.

There was a news story a year or two ago … in Australia I think? … of a farmer that crawled into an underground reservoir that was empty to repair it … his generator or vehicle was running nearby and he lost consciousness inside and died … it’s actually a common enough occurrence for farmers and industrial workers and construction workers

Anyone who is even thinking of building anything underground has to know and understand this dangerous fact