Several recent conversations got me thinking* about what engineering isn’t. There are all sorts of definitions of what engineering is, ranging from pithy and usually inaccurate single sentences to peer-reviewed papers and even entire courses.** I have little to add, and none of it original, to that discussion. What it is not, on the other hand, is less-trodden ground.
I was going to title this post “What Engineers Are Not: Code Monkeys” but decided that was unfair to monkeys. Despite what members of the public*** often think, it is not our job to implement the building code. There are several reasons why this is not true. First, the code represents the minimum standards to**** design and build new buildings. There are often cases where we may want to exceed the minimum. To use a trivial example, our office uses tighter deflection limits than those required by code on certain types of projects. That doesn’t mean we think the code is wrong, but rather that some clients may want a less-bouncy floor than the code allows.
Second, the building code is written primarily for new buildings and the existing-building code***** is rather general. There is no code guidance on many, many real-life conditions that are present in existing buildings, including obsolete materials, archaic frame types, and the effect of previous alterations. There are two ways to deal with these issues: learn something about them, or rip everything apart and replace it. The cost of the second option drives people toward the first.
Third, and the most important, codes change. If you put aside the semi-sensationalistic headline, the article At Risk in a Big Quake: 39 of San Francisco’s Top High Rises points to a critical fact about codes: they change. Codes represent the current agreed-upon state of knowledge****** and that slowly evolves. In the case of earthquake engineering, there are often sudden jumps in code requirements after major quakes reveal problems with the previous requirements. Old seismic designs are therefore a specialized case of archaic frame types, in that they met code when built but may be considered unsafe now without substantial retrofitting.
Where the three points above overlap is that a robot implementing the code as written could not reach a useful answer. Judgement is required, relative costs of different options must be considered, and partial compliance may be the result. Most engineers have a moment of epiphany when they find out that the best answer for a project may depend on forms of thinking other than math and on requirements other than the most recent codes.
* Always a dangerous proposition.
** My sophomore year, I had a one-credit, ungraded seminar called “Engineering Seminar.” It discussed topics that I now find interesting, such as the hiring and training process for young engineers, and our profession’s place in the world. In 1984, I skipped all but two of the lectures.
*** And, occasionally and unfortunately, people who should know better.
**** Hopefully.
***** The IEBC and the NYSEBC. We don’t as yet have an existing-building code in New York City.
****** This is not the same as topics currently being researched.
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