I need to verify the structural systems of the building that was built in Seismic Category D. The building was built in 1988 per UBC 1988. Building consists of concrete tilt up walls (spanning north south), CMU walls (at only one area spanning N-S and East West) and cold form metal stud walls with HSS concentrically braced frames on E-W direction and N-S direction. Roof framing is steel joist girders and joists. The deck is 22 Gage Type B metal deck. Deck is spanning east-west at wings and north-south at the middle section. I realized the original designer took advantage of torsional shear while designing the frames. I was wondering if this is a right approach for a metal deck which would be considered as flexible diaphragm. Also would the deck orientation effect rigidity of the metal deck and distribution of the seismic shear in both directions?