No it is not legal in NYC. There's been a whole discussion of the code though as modern mid/high rises have - concrete, "fireproof" (in terms of adjacent unit

No it is not legal in NYC. There's been a whole discussion of the code though as modern mid/high rises have - concrete, "fireproof" (in terms of adjacent unit to unit) construction - sprinkler systems - internal hallway leading to 2 stairways All of which are lacking in wood frame homes which make up a higher amount of home fire deaths. So there has been an argument that you could build housing much cheaper if you could rely on the concrete & sprinklers, and could lighten the rules around multiple stairs / windows / etc. An interesting debate, with of course, tradeoffs.