> Btw, there's no retrofitting of existing buildings. Most of the laws only apply to new buildings and existing buildings get better as they're renovated. So bu

> Btw, there's no retrofitting of existing buildings. Most of the laws only apply to new buildings and existing buildings get better as they're renovated. So buildings in NYC comply to the safety standard of whenever they were renovated last. But that's the thing that's notable about fire escapes: they were a required retrofit. Building code changes are almost never retroactive, but in response to fires "have two paths of egress" was added, and because it was so important it was made retroactive. It being very difficult to add a stairway to an existing building, external stairways were allowed.