Stiffness Irregularity Check (Soft Story and Extreme Soft Story check) as per ASCE 7-16

what is structural irregularity:
During an earthquake, failure of structure starts at points of weakness. This weakness arises due to discontinuity in mass, stiffness and geometry of structure. The structures having the discontinuity are termed as irregular structures. Stiffness – Soft Story Irregularity: It is defined to exist where there is a story in which the lateral stiffness is less than 70% of that in the story above or less than 80% of the average stiffness of the three stories above.
Stiffness – Extreme Soft Story Irregularity: It is defined to exist where there is a story in which the lateral stiffness is less than 60% of that in the story above or less than 70% of the average stiffness of the three stories above.