You’d think that every landlord in the city would be digging downward and digging outward, whether the city gave them permission to do so or not. There’s so much space under the streets. One-quarter of the land area is street or alley. New York City has 6,300 miles of streets. Basements commonly go down only one or two levels. So a lot of our potentially habitable space is doing nothing but holding up the surface.
The city warns you about the dangers of illegal basement conversions—carbon monoxide poisoning, inadequate ventilation, and the difficulty in getting out in case of a fire. These problems can be mitigated. It’s easier to escape a level-four basement than the 10th level of high-rise.
You don’t need to worry about subways. Subways are 100 or more feet underground, so unless you go down more than four levels, you don’t need to worry about them. The only real problem is all the pipes and wires, especially under the streets, but these are at most only 20 feet under the surface, so you just go below them.
I’m an entrepreneur. An entrepreneur has to take risks. Society benefits when the risks pay off, and the entrepreneur loses when they don’t, so why restrict him?