The seismic storey drift estimation procedure in the 1990 edition of t
he National Building Code of Canada is evaluated for ductile moment-re
sisting frame buildings located in different seismic regions. The eval
uation is based on a comparison of the storey drifts estimated from th
e code procedure with those obtained from the inelastic dynamic analys
is of the buildings. The results indicate that the code procedure unde
restimates storey drift for low-rise ductile moment-resisting frame bu
ildings. It provides good estimates of storey drift for medium- and hi
gh-rise ductile moment-resisting frame buildings. The code estimation
tends to become conservative as the number of storeys increases.