Information on the calculation of torsional moments can be found in the Commentary entitled “Design for Seismic Effects” in the “Structural Commentaries (User’s Guide – NBC 2020: Part 4 of Division B)”. Information on the definition of dead load, W, can be found in the Commentary entitled “Design for Seismic Effects” in the “Structural Commentaries (User’s Guide – NBC 2020: Part 4 of Division B)”.