To limit the probability that the upper storey braced wall panel will be excessively stronger than the lower storey braced wall band, which could lead to a weak storey, which could lead to compromised structural integrity, which could lead to excessive racking.
For floors and constructions supporting floors, this is to limit the probability of:
This is to limit the probability of excessive movement, vibration or deflection of floors, which could lead to negative effects on the psychological well-being of persons.