I have a problem to define the wind load case: the dominating direction is defined by:
0.7 on cos X and -0.7 on cos Y
I want to know if I must introduce this data in one wind case W1 or I have to define two wind case with separating the direction: W1 = 0.7cos X or W2 = -0.7 cos Y because my client insist to introduce 2 separating wind case and he is telling that what I did was wrong (I made one wind case with combining the 2 direction)
So please I need any help or advice to close this matter?

I presume you have "Z" up here?

If you want the wind skewed in the horizontal plane, then yes you would need to define the direction as "you" have stated above: X=0.707, Y=-0.707.

The SRSS of the cosines you enter should produce 1.0.

Thank you Mr Richard.