705.8.4 Mixed openings.
BC § 705.8.4
Where both unprotected and protected openings are located in the exterior wall in any story of a building, the total area of the openings shall be determined in accordance with the following formula: (A p / a p ) + (A u / a u ) ≤ 1 (Equation 7-2) where: A p = Actual area of protected openings, or the equivalent area of protected openings, A e (see Section 705.7). a p = Allowable area of protected openings. A u = Actual area of unprotected openings. a u = Allowable area of unprotected openings.
