[Icemaster]

Local building codes will have to be the guide here. All places I lived, property line went straight vertical, you tree example would mean someone could shear a 100' tree flat against the property line, kind of like it hitting an invisible wall.

A lot of places have setbacks from the property line that vary in size, but going vertical from there I don't know - I'd expect they'd still have to maintain the setback regardless of how tall.