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> Concrete made from Portland cement lasts at least 100 years and generally we don't need more. "We" may not need more (as en "we" that are alive today). But f

> Concrete made from Portland cement lasts at least 100 years and generally we don't need more. "We" may not need more (as en "we" that are alive today). But future generations would thank us if we would make structures that would last for 500+ years instead of 100 years. Much better for the very long term economy AND the climate.

jefftk 4y ago
We don't have a very good idea what sort of structures people will want in 500+ years, and there are lots of better ways we can turn money into improving life for people centuries in the future (primarily in trying to reduce the risk humanity goes extinct before then).
hannasanarion 4y ago
Would they really? Sure, having an old Colosseum or Aqueduct to look at is nice, but do you really want to live in a place where every single square inch of useful ground in the whole country is occupied by an ultra-resilient building that somebody thought would be useful 2000 years ago? We have all of these examples of nice long-lasting roman architecture because those are the examples that survived. Romans didn't live in the Colosseum and the aqueducts. The Romans built hundreds of thousands of other buildings that fell down on their own or were demolished for any number of reasons over the millennia.
- oldgradstudent 4y ago
  You can always demolish unneeded structures. The Golden Gate bridge was opened 85 years ago. Is there any sane reason to demolish it in 15 years?
- tinsmith 4y ago
  In support of this, we can even see the rapid changes in structural demands over half a century in a culture like the US. Suburban sprawl eats up spaces with any viable flexibility in a matter of years, and things like shopping malls fade out of fashion just as quickly as they entered it. In a relatively short time, we are left with brick & concrete hellscapes that are largely being abandoned because developers find it easier (and probably cheaper) to work with fresh land. This Disposable Mentality gets us into obviously environmental and economic messes so often that I am still flabbergasted that the US at large has not adopted a more Reusable Mentality, and incorporated some long-term thinking into their suburban planning.
- trashtester 4y ago
  I said 500+, not 2000. If, 500 years from now, the best 25% of structures built by us remain standing, I think that's a good thing.
Denvercoder9 4y ago
> But future generations would thank us if we would make structures that would last for 500+ years instead of 100 years. Would they? 100 year old houses are already dinosaurs in terms of energy use, and often it's a lot easier and cheaper to demolish and rebuild instead of isolating and installing modern heating. I can't imagine how outdated a 500 year old house would be.
- jaclaz 4y ago
  It depends on what elements you take into account. Demolishing a building and re-building it in terms of total energy (and/or emissions) is not free of costs, maybe you don't pay them directly, unlike heating or air conditioning, but they do exist. Right now 100 years old houses (the brick or stone ones, not the wooden ones, nor the reinforced concrete ones that are usually more recent) already exist and can be restored/upgraded (though of course with some limitations) with a minimal amount of work (in terms of energy and emissions). More or less the "if ain't broken don't fix it approach". Now, if we had some building material lasting only 100 years that could be manufactured with little expense of energy and low or no emissions, that would be another thing. If we imagine that (hypothetical) there is a form of (say) square section bamboo that we can grow at little or no cost and that we can assemble with (still say) some vegetal cement or similar, so that the results of the periodical demolitions can be reused or recycled or that is however biodegradable, then a short lived building would make much more sense.
  - Denvercoder9 4y ago
    > Right now 100 years old houses already exist and can be restored/upgraded with a minimal amount of work (in terms of energy and emissions). Having lived in one, I can assure you that upgrading such a house to modern energy standards isn't a minimal amount of work. Lots of these houses just have a single brick wall directly facing the outdoors. Insulating that means you have to basically completely strip the house down to the brick, and even then it won't be as good as new construction. Of course demolishing and rebuilding also takes energy; but if you amortize it over 50 years or so, I bet in the end you come out ahead. Building technology has improved a lot in energy efficiency over the last century.

jefftk 4y ago

We don't have a very good idea what sort of structures people will want in 500+ years, and there are lots of better ways we can turn money into improving life for people centuries in the future (primarily in trying to reduce the risk humanity goes extinct before then).

hannasanarion 4y ago

Would they really? Sure, having an old Colosseum or Aqueduct to look at is nice, but do you really want to live in a place where every single square inch of useful ground in the whole country is occupied by an ultra-resilient building that somebody thought would be useful 2000 years ago? We have all of these examples of nice long-lasting roman architecture because those are the examples that survived. Romans didn't live in the Colosseum and the aqueducts. The Romans built hundreds of thousands of other buildings that fell down on their own or were demolished for any number of reasons over the millennia.

oldgradstudent 4y ago
You can always demolish unneeded structures. The Golden Gate bridge was opened 85 years ago. Is there any sane reason to demolish it in 15 years?
tinsmith 4y ago
In support of this, we can even see the rapid changes in structural demands over half a century in a culture like the US. Suburban sprawl eats up spaces with any viable flexibility in a matter of years, and things like shopping malls fade out of fashion just as quickly as they entered it. In a relatively short time, we are left with brick & concrete hellscapes that are largely being abandoned because developers find it easier (and probably cheaper) to work with fresh land. This Disposable Mentality gets us into obviously environmental and economic messes so often that I am still flabbergasted that the US at large has not adopted a more Reusable Mentality, and incorporated some long-term thinking into their suburban planning.
trashtester 4y ago
I said 500+, not 2000. If, 500 years from now, the best 25% of structures built by us remain standing, I think that's a good thing.

Denvercoder9 4y ago

> But future generations would thank us if we would make structures that would last for 500+ years instead of 100 years. Would they? 100 year old houses are already dinosaurs in terms of energy use, and often it's a lot easier and cheaper to demolish and rebuild instead of isolating and installing modern heating. I can't imagine how outdated a 500 year old house would be.

jaclaz 4y ago
It depends on what elements you take into account. Demolishing a building and re-building it in terms of total energy (and/or emissions) is not free of costs, maybe you don't pay them directly, unlike heating or air conditioning, but they do exist. Right now 100 years old houses (the brick or stone ones, not the wooden ones, nor the reinforced concrete ones that are usually more recent) already exist and can be restored/upgraded (though of course with some limitations) with a minimal amount of work (in terms of energy and emissions). More or less the "if ain't broken don't fix it approach". Now, if we had some building material lasting only 100 years that could be manufactured with little expense of energy and low or no emissions, that would be another thing. If we imagine that (hypothetical) there is a form of (say) square section bamboo that we can grow at little or no cost and that we can assemble with (still say) some vegetal cement or similar, so that the results of the periodical demolitions can be reused or recycled or that is however biodegradable, then a short lived building would make much more sense.
- Denvercoder9 4y ago
  > Right now 100 years old houses already exist and can be restored/upgraded with a minimal amount of work (in terms of energy and emissions). Having lived in one, I can assure you that upgrading such a house to modern energy standards isn't a minimal amount of work. Lots of these houses just have a single brick wall directly facing the outdoors. Insulating that means you have to basically completely strip the house down to the brick, and even then it won't be as good as new construction. Of course demolishing and rebuilding also takes energy; but if you amortize it over 50 years or so, I bet in the end you come out ahead. Building technology has improved a lot in energy efficiency over the last century.