I think you have a wrong citation there Francis..
Yes I suppose I did in haste by referring to that fact that 701.2 requires each component to comply with the fire-resistance assembly individually.
Think the definition would be a better answer?
ATRIUM. An opening connecting two or more
stories other than enclosed
stairways, elevators, hoistways, escalators, plumbing, electrical, air-conditioning or other equipment, which is closed at the top and not defined as a mall.
Stories, as used in this definition, do not include balconies within assembly groups or
mezzanines that comply with Section 505.
"The definition identifies that an atrium is a floor opening or a series of floor openings that connects the environments of adjacent stories. The definition of “Atrium” excludes enclosed stairways, elevators, hoistways and other similar openings in order to clarify that those elements would not fall under the purview as to what is considered an atrium, and therefore, the associated requirements found in Section 404 would not apply. What this does not preclude is the inclusion of elevators and open stairways within atriums. Such elements would need to be entirely within the atrium to meet the separation requirements found in Section 404.6. Building features, such as stairways, elevators, hoistways, escalators, plumbing, electrical, air conditioning or other equipment openings, are required to be enclosed in fire-resistance-rated shafts in accordance with Sections 712 and 713. Atriums are specified in Section 712.1.7 to address openings in horizontal assemblies. An atrium is not defined by size or use. A series of floor openings that are enclosed with exterior walls, yet open at the roof, would be considered a court and would be exempt from the requirements of Section 404. Balconies associated with assembly occupancies and mezzanines are not considered individual stories that would contribute to the classification of a space as an atrium."
