Are engineers too conservative, and are they guilty of over-designing?

“What are we building here, mate – the Sydney Harbour Bridge???”

It’s the most common question asked of every engineer when he or she gets to site. The moment the steel fixer believes the slab has too much reinforcement, or the fabricator thinks all the steel beams are bigger than they’re supposed to be, the engineer is instantly accused of designing the Harbour Bridge all over again!

Stereotypes aren’t always appropriate or deserved, but the general stereotype levelled against engineers is that we’re all a conservative bunch who over-design everything.   Being over-conservative with our designs or using overly-conservative factors of safety, the presumption is that engineers are risk-averse and too busy covering their backsides than designing efficient structures.

Is there any truth in this? Is the criticism warranted, or is there a bigger picture at play here?

Details