Why are ancient buildings still standing 1500+ years later, but some buildings built like 30 years ago are falling apart?

Question

Why are ancient buildings still standing 1500+ years later, but some buildings built like 30 years ago are falling apart?

In: Other

Answer 1

There’s a few things that are going on here.

First off, we only see the buildings that are still standing. This is survivorship bias. You don’t see thousands upon thousands of buildings that fell from that time.

Second, we’ve gotten better at engineering since then. There’s a phrase in engineering that goes “Anyone can build a bridge, but only an engineer can build a bridge that barely stands”. We could design a building to have the capacity to stand for 1500 years today, but the material and construction cost associated with it would be immense compared to what we’re used to paying for buildings now. Back then they didn’t have the same understandings in engineering, so stuff was typically either overbuilt or underbuilt, and not necessarily built in that just-right sweet spot.