Check out the swimming pool at the bottom. No vacancies but no worries for Vault-Co irregulars.
You may only have a 3x3 meter box in the ground with a portable toilet but it will always seem like a paradise if you survive a solar flare or magnetic reversal.
The guy working on this retrofit is worried about the same things that I am. In addition to everything else, also like me.
Neanderthals are crazy people who do things that make sense, every day, all year 'round. Having a vault just makes sense all the time, no matter what other people think. If other people could think, they'd have vaults of their own. The thing about the ancient rodeo clown is that he is too stupid to understand that he is not capable of doing certain things. He does them anyway. It's the incredible power of severe retardation when it comes to the socially acceptable and physically plausible. Just make sure you use good judgement at all times.