In this method, storey stiffness is estimated as the lateral force producing unit translational lateral deformation in that storey, with the bottom of the storey restrained from moving laterally, i.e., only translational motion of the bottom of the storey is restrained while it is free to rotate.

How do you find the stiffness of a story?

I calculate the gross stiffness initially adding stiffness of all the column i.e. Kcol=12EI/L3, and added all the column stiffness and shear wall stiffness. Increasing the height of any story to 4.5m (all other story are 3.5m height). than the stiffness of the 4.5m story is about the 0.5 times of other story.

What is stiffness of building?

Stiffness is a measure of how much force is required to displace a building by a certain amount. If it requires more force to shift Building A than Building B, we would say that Building A is stiffer.