How do I make a plane mesh cast shadows?

I made most of my wall 3d assets as planes but i noticed that the light goes through the black/useless part of the plane, therefore the wall is not casting any shadows, nor the roof
Cast shadow is enabled…

How do i fix this?

a plane by definition has no depth, so only one side is rendered meaning only one side can block light. to combat this there is two solutions: give the plane depth (make it into a cube like shape) or set your material to two sided.

In the mesh details window: Shadow Two Sided: True