We are currently calculating lease areas for a multi-storey office building with a two-storey atrium. On the second floor the atrium is separated from the adjacent public corridor by a rated glass block fire separation, adjacent janitor's room by a framed fire separation and from the adjacent exit stair by a masonry fire separation. The exterior curtain wall system comprises the fourth face of the atrium

Could you please clarify how the area of the atrium should be treated on the second floor level? Would it still be treated as floor common area? Should it even be included in the Rentable Area for the floor?

Also, would it be treated the same way under the 1996 and 2010 Standards?

Thank-you in advance for your prompt assistance.