Wind Load Calculator
BS 6375-1 Annex A
BS 6375-1: Performance of windows and doors. Classification for weathertightness and guidance on selection and specification.
Specifies the exposure categories related to test pressure levels for air permeability, watertightness and wind resistance for external windows and doorsets. The weather classification should be selected on the particular design wind load to Table 1.
BS 1026: Windows and doors. Air permeability. Test method
Air Tightness classifications are based on the measured air leakage for a range of pressures from 50Pa to 600Pa. Where 600Pa is equivalent to around 60mph winds. Class 2 permissible air leakage is 17m3/hr.m2 at 50Pa