This is really difficult business and I recently ended in a dispute with my civil engineer wife because I wanted to move a shelf towards the center of the room.

This is really difficult business and I recently ended in a dispute with my civil engineer wife because I wanted to move a shelf towards the center of the room. She is I guess right reminding me that trial and error is not a good strategy in her business. I always think, that a 120 year old building somehow should not collapse due to my books. However, when it comes to earthquake standars over time it really gets even stranger. I live in a region in Germany that recently got an 'upgrade' on earth quake forces after recent surveys. However, regulators still do not enforce new standards. So my wife has to recommend all her customers to adopt new standards, but tells them in the same sentence that it is not yet required. With rising construction costs nobody choses to. So we are all waiting cynically for the predicted major earthquake so that we are on the same standard again. Some by design, some empirically proven.