The interstorey drift limitations in earthquake codes of various count
ries around the world, have been reviewed. It is emphasized that, the
aseismic safety of a tall building as well as its susceptibility to no
nstructural damage are primarily indexed to its ability to restrict th
e relative storey displacements, in addition to its adequate strength,
ductility and toughness. A moment resisting frame building satisfying
all requirements of strength and ductility may still be subject to se
vere nonstructural damage, if the interstorey drifts are not restricte
d properly by means of shear walls. Several stringent deflection crite
ria as well as a damage control index are introduced to be conscientio
usly determined and checked during the design calculations for the pur
pose of controlling damage especially to nonstructural elements. Copyr
ight (C) 1996 Published by Elsevier Science Ltd.