> Both events occurred on mechanical floors that have been criticized for being excessively tall — a design feature that allowed the developers to build higher

> Both events occurred on mechanical floors that have been criticized for being excessively tall — a design feature that allowed the developers to build higher than would otherwise have been permitted, because mechanical floors do not count against the building’s allowable size. I've never heard of an allowable size expressed in terms of number of non-mechanical floors. That sounds rather ill-conceived. Why would you have limits beyond a plain maximum height ?