"They don't design them like they used to"

Everyone is familiar with the phrase "they just don't build them like they used to". Typically, this comment is made after something breaks or falls apart - apparently due to poor construction. The frustrated owner recalls a time when things were built to a much higher standard. They seem to remember that things used to be built with stronger materials, more bolts, more welds, and bigger beams and columns.

Well, are they right? For whatever reason I was thinking about this the other day and realized that it is most likely a fallacy to say that things used to be "built" better. The likely reality is that things used to be "overbuilt". What I mean by that, is that there was no real design going on when great grandpa built his house. In order to compensate for lack of design, you basically end up overbuilding.

These days, there is engineering behind everything that is built or manufactured. If it falls apart or breaks much sooner than it is supposed to, then it may be much more accurate to blame it on the designer rather than the builders. After all, it is the designer that calculates the size of the beams and the number of bolts that are needed to build something. They calculate how much strength something needs to have, then they use just enough materials to build it. Without these calculations, the builder would have to take a much more conservative approach and use more and bigger materials. The end result, of course, is that the final product would be much sturdier.

I guess we can't blame it all on the designers. Surely there are other factors at play. When a television set is designed it may be designed to handle "normal use" for a predetermined life span. Ideally (for the business) the product lasts just long enough so that it is not considered defective when it breaks. If you design for a life much longer than this, then you are just wasting money on materials and possibly labor.

So its not that great grandpa intentionally built the house to stand up for 150 years, rather he just built it so that it was obviously sturdy and moved on. Today, when questioned about the scrawny beams being used to construct a building, the engineer is likely to respond by saying that the beams have been sized to adequately support the calculated dead and live loads using a standard-of-the-practice factor of safety and a deflection within the specified tolerance. Yay for engineering and houses that sway when the wind blows.