*Wind loads for the design of the main wind-force resisting system are illustrated and specified in the **following figures, tables, and formulas. A plus (+) sign denotes pressure toward a surface and a minus (-)sign denotes pressure away from a surface. What is MWFRS? Here we will explain.*

*MWFRS **Main Wind-Force Resisting Systems for Buidling*

*MWFRS*

*Main Wind-Force Resisting Systems for Buidling*

*External pressure coefficients (Cp) are given in Tables VIII and IX. Figure 1 designates building geometry, and Figure 2 illustrates design wind pressure.*

*Design Wind Pressures (p) for buildings with height/least horizontal dimension > 4 and f > 1.0 cycle/second, design wind pressures shall be as follows:*

*qz for windward wall at height Z above ground.*

* qh for leeward wall at mean roof height Obtain.*

* qz or qh from Table VI (exposure C) or Table VII (exposure D).*

*G = 0.85 for exposure C or D.*

*For flexible buildings or buildings with height/least horizontal dimension > 4, or the natural frequency, **f < 1.0 cycle/second, design wind pressure shall be in accordance with ASCE 7-95, including appendix and **commentary.*

*Figure 1 – Building Geometry Designation*

*Figure 2 – Design Wind Pressures Cp*

*Table VIII – Wall Pressure Coefficient, Cp Design Wind Pressures*

*Notes:*

*B = Horizontal dimension of building, in m (ft), measured normal to wind direction.*

*L = Horizontal dimension of building, in m (ft), measured parallel to wind direction.*

*Table IX – Roof Pressure Coefficient, Cp*

*Note:*

*L = Horizontal dimension of building, in m (ft), measured parallel to wind direction.*

*h = Mean roof height in m (ft), except that eaves height shall be used for Ѳ ≤ 10 degree*

*Ѳ = Angle of plane or roof from horizontal, in degrees.*

*a – For roof slopes greater than 80 degree, use Cp = 0.8.*

*b – Value is provided for interpolation purpose.*

*c – Value can be reduced linearly with area over which it is applicable as follows:*

*Additional Notes:*

*Plus and minus signs signify pressures acting toward and away from the surface respectively.*

*Linear interpolation is permitted for values of L/B, h/L, and * other than shown. Interpolation shall only be **carried out between values of the same sign. Where no value of the same sign is given, assume 0.0 for **interpolation purposes.*

*When two values of Cp **are listed, this indicates that the windward roof slope is subjected to either positive **or negative pressure and the roof structure shall be designed for both conditions. Interpolation for **intermediate ratio of h/L in this case shall only be carried out between Cp values of like sign. **For monoslope roofs, entire roof surface is either a windward or leeward surface.*

* Components and Claddings*

*Components and Claddings*

*Roof overhangs for all buildings shall be designed for the pressure determined from the pressure coefficient given in Figure A2B (ASCE 7-95, Figure 6-5B). For more information, see Figures A2, A2A, A2C, A3 to A5.*