No later than January 1, 2015, doors and frames in stairways in all existing residential buildings and buildings of mixed residential occupancy exceeding 80 feet in height above grade shall have a fire resistance rating of at least one hour.
(Added Coun. J. 12-15-04, p. 39962, § 7; Amend Coun. J. 12-14-11, p. 18115, § 1)