I am working on a code analysis for a project.
We have a two story atrium open to the second floor. Section 404.5 says a smoke control system is not required for atriums that connect only two stories. OK fine.
Section 404.6 calls for atriums be separated from adjacent space by a 1-hr fire barrier. However, exception 3 says a fire barrier is not required between atrium and adjoining spaces of any three floors of the atrium provided such spaces prvided such spaces are accouted for in the design of the smoke control system.
I interpret this to mean that we are not required to provide a smoke control system OR a 1-hr fire barrier. Am I correct in that interpretaton? I'm concerned about the wording for Section 404.6, Exception 3 where it says "...provided such spaces a accounted for in the design of the smoke control system." 404.5 says I'm not requred to have a smoke control system for a two story atrium therefore I do not need to account for its design.
Any clarification/advice would be apprecated.