Working above a neighbor's roof: BC 3309.10 protection and access
When work takes place above an adjoining property's roof, NYC requires protection of that roof and an access agreement with the neighbor. What triggers it and why it delays jobs.
Do I need the neighbor's permission to work above their roof in NYC?
If your work is above an adjoining property, you need to protect that roof and you need an access agreement with its owner. This is the item that most often delays a facade job, because it depends on a third party who has no deadline.
What matters on a real job
Protection is physical and legal
You protect the roof, and you paper the access. Both.
Start it early
Access agreements are negotiated, not filed. A neighbor who will not sign can stop a lot line elevation indefinitely.
It shows up at the lot line
Rear and side elevations on tight lots are where this bites.