The first step is to calculate the representative values of gravity load of each layer (including the values of beam, column, plate and live load).

Secondly, the shear force of each layer is obtained by the gravity load.

The third step is to calculate the lateral stiffness of each layer (different from the linear stiffness of beams and columns)

The fourth step, the story displacement is the ratio of the shear force of each story to the lateral stiffness of each story, generally in meters.