Anyone who’s lived outside of Manhattan knows the deal: there are dozens of basement dwellings up for rent any day of the week in the five boroughs. Known as ADUs (accessory dwelling units), they’re nearly all based out of row houses and condos in outer boroughs, particularly in low-rent neighborhoods. You won’t be able to find them on all the major sites, however, because these spaces are, and always have been, illegal. Even with all the standard requirements — two exits, windows, proper ventilation, running hot water, etc — these units are illegal because they are more than 50% below ground.
If you’ve ever lived in your parents’ basement, it’s not hard to see why the city has outlawed these dwellings for decades. Most landlords don’t bother keeping their basements furnished or in any state of repair, and they don’t have to because basement renters won’t complain. They’re caught in the catch-22 of NYC apartment rentals: they can’t report irresponsible landlords, and they won’t report them because basements are so cheap.