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Comment by DenisM | Hacker News Reader

In an earlier thread someone working in the industry said that today the cement producers can make arbitrarily sturdy concrete, but almost no one wants to pay for the top-tier stuff.

Part of it nearsighted thinking, the other part is consideration that money could be spent on like nicer decor, or maybe build larger number of 100 year buildings than a smaller number of 1000 year buildings.

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If the choice is between using the money for one building that lasts 1000 years or 10 buildings that last 100 years, each, I'd pick the ten buildings, too. There will be new considerations anyway. Like cables, which weren't a thing 500 years ago. Or water pipes. Who knows what else we will want to put in our buildings, that are easier done with building something new than updating something old.

I think it's the much greater PSI concrete... https://www.wired.com/2007/04/irans-superconc/

Regular concrete can last for 100 years and who knows how design /needs can change during that so it makes sense not to build with much more expensive 500 year concrete.

Bridges are another story.

Isn’t it the height of hubris to believe we could plan 100 years ahead? What cities haven’t radically changed in the last 100 years, with nearly everything being replaced with something better than they could have conceived of?

Were the ancient Roman aqueducts the height of hubris?

The Golden Gate Bridge was conceived of 103 years ago, and began construction 87 years ago.

https://en.wikipedia.org/wiki/Golden_Gate_Bridge#Conception

Buildings and roads are technologies that have existed for thousands of years, and may continue to exist for thousands of years. If you want to protect people and things from the world, it's hard to do better than walls and a roof. If you want to get from point A to point B by land, it's hard to do better than a network of cleared spaces. Sure, we may not know exactly what people in 100 years will want, but it's likely they'll still want buildings and roads.

That's an interesting philosophical question.

I suspect monuments are the only thing that benefit from longevity.

I was imaginging government buildings built for 100 years, but I figure climate control and window design has radically changed and older buildings are probably uncomfortable in these ways without retrofitting.

I get the point you're trying to make but 100 years is not a long time-scale for construction projects a bit larger than a single-family home. I think expecting the foundations and the facade of a building to last 200-300 years is reasonable.

I've lived a large part of my life in a house that is about a hundred years old. The house I'm currently living in is about sixty years old. That's really not a long time in the life of a city.

> What cities haven’t radically changed in the last 100 years, with nearly everything being replaced with something better than they could have conceived of?

95% of European cities downtown?

You’d be surprised. Almost all of the German cities were destroyed in WW2 (meaning their downtown area). The same goes for Polish cities, or further East cities like Kiev, Odessa or Kharkiv. WW2 was also quite brutal for Western cities like Rotterdam or London. WW1 obliterated most of the cities in Northern France and South-West Belgium. The streets of Madrid saw active and intense fighting in the Spanish Civil War. And many of the cities that escaped the wars relatively unscathed had to contend with the modernist movement of the 1960s and the 1970s, which saw many interesting buildings demolished because they didn’t look modern or functional enough (Athens being a prime example for this).

Lol my house is 150 years old and I’ve just bought it

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