Apocalypse Disasters: An Architect Builds a Stockpiled Island

In the apocalypse of torrential rain, everyone else frantically stockpiles food, while I stockpile sandpaper and caulking. My girlfriend calls me crazy, until the flood reaches the third floor and the only light shines from my balcony. Later, they beg on their knees to be let in, while I draft a “Post-Apocalyptic Housing Agreement.” When survival becomes a branch of engineering, I am the only examiner.

How many rules does humanity need before it can live without becoming beastlike?