The number is 40% in Manhattan (buildings, not homes though). https://www.nytimes.com/interactive/2016/05/19/upshot/forty-percent-of-manhattans-buildings-could

The number is 40% in Manhattan (buildings, not homes though). https://www.nytimes.com/interactive/2016/05/19/upshot/forty-percent-of-manhattans-buildings-could-not-be-built-today.html https://www.nytimes.com/interactive/2016/05/19/upshot/forty-...