The following language is adopted as a new Section 605:
"605. BASEMENT CONSTRUCTION
605.1 General.
In all buildings, basement construction shall comply with the requirements of Sections 605.2 through 605.4.
605.2 Basement columns and bearing walls.
In buildings of Type III or V construction with three or more stories above grade plane, all basement columns and basement bearing walls shall be of noncombustible material or of heavy timber construction.
605.3 Multiple basement stories.
In buildings with more than one basement story, the floor construction separating the highest basement from the first story above grade plane and all construction below that level shall be of Type IA construction.
605.4 Floor construction.
Except in buildings of Group R-5 occupancy, floor construction over basements shall have a fire-resistance rating of not less than 1 hour."