Structures designed and built-in seismic regions shall fulfill the following fundamental requirements: The structure shall be designed and constructed to withstand the design seismic forces without local or global failure, thus retaining its structural integrity, stability against overturning, and a residual load-bearing capacity after the earthquake. Further, it is also necessary to avoid damage to nonstructural systems which are essential for safe evacuation from the structure. The design seismic force is expressed in terms of 475 years return period (reference return period) and the importance factor.

The structure shall be designed and constructed to withstand a seismic force having a larger probability of occurrence than the design seismic forces, without the occurrence of damage and the associated limitations of the use of the structure. The critical facilities need to be operational state or in a state which can be returned to a fully operational state shortly after the earthquake (within minutes to hours). The design seismic force associated with damage limitation is expressed in terms of a fraction of life safety level seismic force.