In the Irregularity Report, Weak Story Irregularities are checked and necessary conditions are applied.


Discontinuity in lateral strength–weak story irregularity, is calculated as follows.

The Strength Irregularity Coefficient= ( Str )i / ( Str )i+1 < 0.80

Discontinuity in lateral strength–extreme weak story irregularity, is calculated as follows.

The Extreme Strength Irregularity Coefficient= ( Str )i / ( Str )i+1 < 0.65

In according to article 12.3.3.2, structures assigned to Seismic Design Category E or F that have horizontal irregularity Type 1b of Table 12.3-1 or vertical irregularities Type 1b, 5a, or 5b of Table 12.3-2 shall not be permitted.

In according to article 12.3.3.2, structures with a vertical irregularity Type 5b, as defined in Table 12.3-2, shall not be more than two stories or 30 ft (9 m) in structural height, hn.