Julien, what is the construction of the ceiling? gypsum board? At a minimum I would consider the attic hatch to be a closure. thus if the ceiling requires a rating, so does the closure. I would consult with the building department to see if a permit was obtained to complete and work in separating the building into a triplex… If the work was not completed under a permit, an inspection order under “F” in order for them to apply for a building permit to construct an adequate fire separation, and this would also resolve the hatch issue… MY 2 cents!