8 ms·

The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all t

The largest issue with concrete is that we misuse it. As a building material it has great thermal mass ( aiding temperature stability ) and longevity. But all too often buildings are poorly designed for renovation, and hence end up being torn down after a couple of decades. A small fraction of the useful lifetime of the structure. Any building using concrete for a structure should be aiming to last at least 100 years. For those who didn't read the article: the chemistry of Portland cement works against it. Production requires heating the calcium carbonate to a high temperature to extract carbon dioxide from it. Which obviously produces large amounts of CO2 proportional to concrete production. However, concrete also absorbs carbon dioxide from the air over its lifetime. So the measured emissions aren't the entire story. Perhaps in future we will consider this an excellent source of carbon dioxide for the production of various hydrocarbons. I've heard of several efforts to create octane using carbon dioxide from the air, but you need a large amount of energy to extract a useful amount of CO2. Well this would be a good source of high concentration CO2. Perhaps not for octane ( we should really be moving away from combustion engines ) but perhaps plastics and other products that are currently derived from crude oil.

jmiskovic 6y ago
Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. City layout could change drastically. Monumental buildings should last a long time, but not every structure. The alternative is to build from wood whenever possible, and capture extra cabon in building material. This increases market need for wood and therefore forestation.
- wiz21c 6y ago
  My house is at least 200 year old and have been inhabited by 4-5 families. Although I must admit that it is thermally very bad, its perfectly livable. Now the thing is that I like old houses. So, just pay a nice marketing team to make sure people love old houses (after all, we have marketing team that can sell poison such as cigarettes or carbon dioxide). Or, as you said, just build with something easier to handle such as wood (provided you recycle it, else it'll go back to biomass, releasing its CO2 again)
- notahacker 6y ago
  > Do we want 100 year old buildings? At least a fifth of the UKs housing stock is over a century old, so the answer to that question is yes, if they're built properly...
  - lotsofpulp 6y ago
    I haven’t been impressed by any of the old UK houses I’ve been in, from rowhouses in London to detached houses in a midlands to mansion in Cotswald. The insulation, pipes, and wiring all are quite inferior to modern standards.
    - pornel 6y ago
      London especially suffers from lots of shoddy conversions. However, buildings built today to today's modern standards (with a little foresight) could easily be fine 100 years in the future. I'm not talking about fragile glass showpieces, but simple properly insulated homes built from durable materials.
    - nemo44x 6y ago
      We call that “character”. My biggest issue with old homes is the layouts tend to be weird for today’s uses. Where I live many of the homes have a lot of small rooms and and narrow doorways instead of larger ones, for instance. This of course goes back to conserving heat. But it makes house hunting difficult when trying to find a house with a layout you like.
- narag 6y ago
  Do we want 100 year old buildings? The house where I grew up was made before Portland came to our zone, so it was made of lime mortar and rocks, some of them as big as a mellon, I found out when I tried to drill the walls to put a basketball basket. It was demolished in the eighties, but not because it was in bad shape. I met the bulldozer operator years later and he recalled how he had a hard time with it. I'm sure it would have been fine today, when it would be 100 y.o. or close. And I'm sure there's no other place where I'd rather live. It was cool in the summer, easy to warm in the winter, no mold, little noise from the outside.
- mrweasel 6y ago
  >Do we want 100 year old buildings? I don't want a new house. Why? Because I refuse to live in a house with no natural ventilation. Most modern houses need air condition or at least ventilation systems, because they need to be so energy efficient, that there is no other way to get fresh air in. The fact that a house needs to be pressure tested seems insane. Sure you can leave the windows open, but that defeats the purpose. Modern home needs to be ventilated three times a day, that means opening all the windows in the morning, when you get home in the afternoon and before going to bed. How many people will remember to do that? The air in a modern home is often so dry that my nose start running the minute I enter. I don't want to live in that sort of climate. Depending on the country, I think people should aim for home built from the late 1940 to mid 1970. Most likely additional isolation and new windows have been added over the years, making them reasonably energy efficient.
  - frosted-flakes 6y ago
    Most new homes today include heat recovery ventilators that continuously cycle the air from outside.
  - leetcrew 6y ago
    > Sure you can leave the windows open, but that defeats the purpose. Modern home needs to be ventilated three times a day, that means opening all the windows in the morning, when you get home in the afternoon and before going to bed. How many people will remember to do that? I don't really understand your objection. in a leaky old style building without an effective moisture/thermal barrier, you don't get to choose whether ventilation is happening; it always is. with modern sealing, you can open the windows if you prefer fresh air, or you can enjoy much more efficient AC/heat if you don't. why couldn't you live in a modern home and just leave the windows open? it's easy to get a good draft going in any multifloor building with windows.
    - jakear 6y ago
      > open the windows if you prefer fresh air, or you can enjoy much more efficient AC/heat How can something powered by electricity/natural gas/etc be more efficient than simply opening the windows and letting Mother Nature do the work?
- dukeyukey 6y ago
  The house I grew up in in rural UK was built in about 1910. My university accommodation was built in the 1880s. The first place I lived in when I moved to London was Victoria, as is where I'm living now. The newest place I've lived for longer than a few months was a flat-share in a 1960s block. For huge amounts of people, >100 year old housing is the norm.
- ben_w 6y ago
  I’m looking to buy a place in Berlin, and from the search results it feels like half of the apartment buildings are from 1880-1910. I’m renting in a very old (not sure exactly how old) building, and it is… fine. It has been renovated, it is warm, it has double glazing. The only thing wrong with it is the walls are too thin for modern sound systems, but even that is less of a problem here than (for example) my university accommodation in Aberystwyth, because Germans care a lot about quiet time. The only reason I’m skipping anything pre-1950 is that I want to own it for at least 30 years.
- throw0101a 6y ago
  > Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. My parents live in a house that was originally built in the 1890s. It first had a fire place and wood stove for eating/cooking (surmised via chimneys), then it had gas lighting (some pipe are still in the walls), then it knob-and-tube lighting, then modern electrical lighting and cooking. Walls were replaced, insulation added, etc. Lots of internal changes. But the foundations and external brick is original (AFAICT). Buildings are just boxes for people which keep the cold/heat/moisture at a comfortable level. As long as the "bones" of the buildings are good seismically, the "skin" has proper environmental control, then you can shuffle the inside around without too many issues. Design/build things with minimal internal load-bearing walls and things can be shuffled fairly easily. Perhaps also use trusses instead of rafters as well for easier running of piping/wire.
  - nom 6y ago
    > Buildings are just boxes for people which keep the cold/heat/moisture at a comfortable level. So true. With the knowledge we have now about building materials you could create a very versatile, rigid, energy efficient base structure that lasts > 100 years, and adapt/update the internals to the current needs. You could even change the room layout completely. I live in Europe and I can't understand why houses in the US are built with wood and drywall. It surely must be cheaper to use bricks/concrete and then renovate it fully every 20 years, or am I wrong here?
    - decasteve 6y ago
      You are not wrong. However, houses could still be built from wood like the 500 year old houses and churches made with actual timbers. Timber framed houses would use a lot less wood in the long run due to less waste and greater longevity (especially when coupled with bricks and concrete). Milling large trees down to 2x4s and coupling it to drywall to build homes that don't last is a travesty.
      - lostlogin 6y ago
        What are you counting as a house that hasn’t lasted? 50 years? 100? The house I am in was built in the 1940’s by the state as an employment and housing scheme for returned servicemen post WW2. It’s wood framed and has a fair few years of life left if cared for. The bulk of NZ houses are wooden, and have been for its entire history. They are also cold and are often damp, though these problems can be solved with decent building practices. Concrete and brick are not that desirable in an earthquake prone country. And yes, milling big old trees is bad. They are now made of treated pine, which comes with its own environmental concerns.
- barumi 6y ago
  > Do we want 100 year old buildings? Obviously, we do. To put it in terms that may be easier to understand, we do not want to demolish a building when it serves all functional requirements. Double so if they have urban and cultural value. I suggest you visit places such as Amsterdam, where most of the city center was built in the 17th century and it's glorious.
- deleted 6y ago
  [deleted]
- novok 6y ago
  I think we do, if we design them properly in the first place. For example, in 11 years the empire state building will be 100 years old, and its still an very useful and beautiful building. I think as long as you design a building to use something like conduits, you can update the wiring, plumbing, hvac, elevators, etc over time and it can continue to be useful for centuries.
nabla9 6y ago
In Finland there is effort to capture carbon from industrial emissions and eventually from the air. Pulp mills are very promising. Turning the cons of concrete into pros (carbon-cured concrete) https://www.vttresearch.com/en/news-and-ideas/turning-cons-concrete-pros https://www.vttresearch.com/en/news-and-ideas/turning-cons-c... >carbon-cured concrete: in carbon curing, concrete is cured with gaseous carbon dioxide, from the plastic phase forward. The curing of concrete with pressurized carbon dioxide generates not only the ordinary reaction products of cement but also carbonate-based reaction products. Consequently, the process binds carbon dioxide, and it is even possible to make the final product carbon negative if ordinary cement is replaced with alternative binders with a low carbon footprint. The Carbon Reuse Economy: Transforming CO2 from a pollutant into a resource https://cris.vtt.fi/en/publications/the-carbon-reuse-economy-transforming-co2-from-a-pollutant-into-a https://cris.vtt.fi/en/publications/the-carbon-reuse-economy...
asiachick 6y ago
I don't think we want 100yr old buildings (except for history like a famous temple etc.). Certainly in my country old buildings are not designed in any environmentally conscious way. They aren't energy saving. They aren't in any way designed to be naturally cooler in the summer or hotter in the winter. They aren't designed for the changing needs of society which went from walking and horses 100 years ago whatever it is today. Why would I think a building made today is going to be a good building for the needs of people 100yrs from now?
- Retric 6y ago
  Many old buildings where designed to be cool in the summer and warm in the winter. Often those features have been removed as historically airflow kept things cool where today you want to maintain AC. It’s something of a design failure of modern buildings where walking outside when it’s 80f is pleasant but inside you need AC at those temperatures.
barumi 6y ago
> Any building using concrete for a structure should be aiming to last at least 100 years. I don't know which country you have in mind but in Europe the construction industry by law is obligated to design concrete structures for residential buildings that ensures a useful life of at least 50 years, and by definition that means that the building structure shall not require maintenance for at least 50 years. Moreover, concrete as a widespread structural material is relatively new, and city centers are still packed with contrete buildings that were built when the technology started popping up. In fact, in general a building with concrete structure is only demolished when it's not possible to retrofit or renovate it effectively, due to unrelated reasons such as increasing occupation density that would not be cost-effective by reinforcing the concrete structure. My point is that concrete structures are not demolished with enough frequency to be of any concern. The main reason is that concrete structures are simply too expensive to be demolished, moreso in urban centers. Thus your concern simply isn't relevant in the real world because economics already impose the same restrictions that are expressed in your environmental concerns.
- stjohnswarts 6y ago
  Maybe in Europe, but in the United States if you want to tear down a building and build another one, there is about a 99% chance you can do that and get the paperwork for it without too many hurdles other than NIMBYs.
  - barumi 6y ago
    That's an entirely unrelated issue, and fits the case of urban renewal projects whose preexisting building is not able to accommodate new functional requirements, at least in a cost-effective way. The only factor that the use of concrete plays in this scenario is that concrete structures are expensive and time-consuming to demolish. If the investment makes financial sense then the choice of building material doesn't make any difference.

jmiskovic 6y ago

Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. City layout could change drastically. Monumental buildings should last a long time, but not every structure. The alternative is to build from wood whenever possible, and capture extra cabon in building material. This increases market need for wood and therefore forestation.

wiz21c 6y ago
My house is at least 200 year old and have been inhabited by 4-5 families. Although I must admit that it is thermally very bad, its perfectly livable. Now the thing is that I like old houses. So, just pay a nice marketing team to make sure people love old houses (after all, we have marketing team that can sell poison such as cigarettes or carbon dioxide). Or, as you said, just build with something easier to handle such as wood (provided you recycle it, else it'll go back to biomass, releasing its CO2 again)
notahacker 6y ago
> Do we want 100 year old buildings? At least a fifth of the UKs housing stock is over a century old, so the answer to that question is yes, if they're built properly...
- lotsofpulp 6y ago
  I haven’t been impressed by any of the old UK houses I’ve been in, from rowhouses in London to detached houses in a midlands to mansion in Cotswald. The insulation, pipes, and wiring all are quite inferior to modern standards.
  - pornel 6y ago
    London especially suffers from lots of shoddy conversions. However, buildings built today to today's modern standards (with a little foresight) could easily be fine 100 years in the future. I'm not talking about fragile glass showpieces, but simple properly insulated homes built from durable materials.
  - nemo44x 6y ago
    We call that “character”. My biggest issue with old homes is the layouts tend to be weird for today’s uses. Where I live many of the homes have a lot of small rooms and and narrow doorways instead of larger ones, for instance. This of course goes back to conserving heat. But it makes house hunting difficult when trying to find a house with a layout you like.
narag 6y ago
Do we want 100 year old buildings? The house where I grew up was made before Portland came to our zone, so it was made of lime mortar and rocks, some of them as big as a mellon, I found out when I tried to drill the walls to put a basketball basket. It was demolished in the eighties, but not because it was in bad shape. I met the bulldozer operator years later and he recalled how he had a hard time with it. I'm sure it would have been fine today, when it would be 100 y.o. or close. And I'm sure there's no other place where I'd rather live. It was cool in the summer, easy to warm in the winter, no mold, little noise from the outside.
mrweasel 6y ago
>Do we want 100 year old buildings? I don't want a new house. Why? Because I refuse to live in a house with no natural ventilation. Most modern houses need air condition or at least ventilation systems, because they need to be so energy efficient, that there is no other way to get fresh air in. The fact that a house needs to be pressure tested seems insane. Sure you can leave the windows open, but that defeats the purpose. Modern home needs to be ventilated three times a day, that means opening all the windows in the morning, when you get home in the afternoon and before going to bed. How many people will remember to do that? The air in a modern home is often so dry that my nose start running the minute I enter. I don't want to live in that sort of climate. Depending on the country, I think people should aim for home built from the late 1940 to mid 1970. Most likely additional isolation and new windows have been added over the years, making them reasonably energy efficient.
- frosted-flakes 6y ago
  Most new homes today include heat recovery ventilators that continuously cycle the air from outside.
- leetcrew 6y ago
  > Sure you can leave the windows open, but that defeats the purpose. Modern home needs to be ventilated three times a day, that means opening all the windows in the morning, when you get home in the afternoon and before going to bed. How many people will remember to do that? I don't really understand your objection. in a leaky old style building without an effective moisture/thermal barrier, you don't get to choose whether ventilation is happening; it always is. with modern sealing, you can open the windows if you prefer fresh air, or you can enjoy much more efficient AC/heat if you don't. why couldn't you live in a modern home and just leave the windows open? it's easy to get a good draft going in any multifloor building with windows.
  - jakear 6y ago
    > open the windows if you prefer fresh air, or you can enjoy much more efficient AC/heat How can something powered by electricity/natural gas/etc be more efficient than simply opening the windows and letting Mother Nature do the work?
dukeyukey 6y ago
The house I grew up in in rural UK was built in about 1910. My university accommodation was built in the 1880s. The first place I lived in when I moved to London was Victoria, as is where I'm living now. The newest place I've lived for longer than a few months was a flat-share in a 1960s block. For huge amounts of people, >100 year old housing is the norm.
ben_w 6y ago
I’m looking to buy a place in Berlin, and from the search results it feels like half of the apartment buildings are from 1880-1910. I’m renting in a very old (not sure exactly how old) building, and it is… fine. It has been renovated, it is warm, it has double glazing. The only thing wrong with it is the walls are too thin for modern sound systems, but even that is less of a problem here than (for example) my university accommodation in Aberystwyth, because Germans care a lot about quiet time. The only reason I’m skipping anything pre-1950 is that I want to own it for at least 30 years.
throw0101a 6y ago
> Do we want 100 year old buildings? I don't think we can predict the needs of building even 20 years into the future. My parents live in a house that was originally built in the 1890s. It first had a fire place and wood stove for eating/cooking (surmised via chimneys), then it had gas lighting (some pipe are still in the walls), then it knob-and-tube lighting, then modern electrical lighting and cooking. Walls were replaced, insulation added, etc. Lots of internal changes. But the foundations and external brick is original (AFAICT). Buildings are just boxes for people which keep the cold/heat/moisture at a comfortable level. As long as the "bones" of the buildings are good seismically, the "skin" has proper environmental control, then you can shuffle the inside around without too many issues. Design/build things with minimal internal load-bearing walls and things can be shuffled fairly easily. Perhaps also use trusses instead of rafters as well for easier running of piping/wire.
- nom 6y ago
  > Buildings are just boxes for people which keep the cold/heat/moisture at a comfortable level. So true. With the knowledge we have now about building materials you could create a very versatile, rigid, energy efficient base structure that lasts > 100 years, and adapt/update the internals to the current needs. You could even change the room layout completely. I live in Europe and I can't understand why houses in the US are built with wood and drywall. It surely must be cheaper to use bricks/concrete and then renovate it fully every 20 years, or am I wrong here?
  - decasteve 6y ago
    You are not wrong. However, houses could still be built from wood like the 500 year old houses and churches made with actual timbers. Timber framed houses would use a lot less wood in the long run due to less waste and greater longevity (especially when coupled with bricks and concrete). Milling large trees down to 2x4s and coupling it to drywall to build homes that don't last is a travesty.
    - lostlogin 6y ago
      What are you counting as a house that hasn’t lasted? 50 years? 100? The house I am in was built in the 1940’s by the state as an employment and housing scheme for returned servicemen post WW2. It’s wood framed and has a fair few years of life left if cared for. The bulk of NZ houses are wooden, and have been for its entire history. They are also cold and are often damp, though these problems can be solved with decent building practices. Concrete and brick are not that desirable in an earthquake prone country. And yes, milling big old trees is bad. They are now made of treated pine, which comes with its own environmental concerns.
barumi 6y ago
> Do we want 100 year old buildings? Obviously, we do. To put it in terms that may be easier to understand, we do not want to demolish a building when it serves all functional requirements. Double so if they have urban and cultural value. I suggest you visit places such as Amsterdam, where most of the city center was built in the 17th century and it's glorious.
deleted 6y ago
[deleted]
novok 6y ago
I think we do, if we design them properly in the first place. For example, in 11 years the empire state building will be 100 years old, and its still an very useful and beautiful building. I think as long as you design a building to use something like conduits, you can update the wiring, plumbing, hvac, elevators, etc over time and it can continue to be useful for centuries.

nabla9 6y ago

In Finland there is effort to capture carbon from industrial emissions and eventually from the air. Pulp mills are very promising. Turning the cons of concrete into pros (carbon-cured concrete) https://www.vttresearch.com/en/news-and-ideas/turning-cons-concrete-pros https://www.vttresearch.com/en/news-and-ideas/turning-cons-c... >carbon-cured concrete: in carbon curing, concrete is cured with gaseous carbon dioxide, from the plastic phase forward. The curing of concrete with pressurized carbon dioxide generates not only the ordinary reaction products of cement but also carbonate-based reaction products. Consequently, the process binds carbon dioxide, and it is even possible to make the final product carbon negative if ordinary cement is replaced with alternative binders with a low carbon footprint. The Carbon Reuse Economy: Transforming CO2 from a pollutant into a resource https://cris.vtt.fi/en/publications/the-carbon-reuse-economy-transforming-co2-from-a-pollutant-into-a https://cris.vtt.fi/en/publications/the-carbon-reuse-economy...

asiachick 6y ago

I don't think we want 100yr old buildings (except for history like a famous temple etc.). Certainly in my country old buildings are not designed in any environmentally conscious way. They aren't energy saving. They aren't in any way designed to be naturally cooler in the summer or hotter in the winter. They aren't designed for the changing needs of society which went from walking and horses 100 years ago whatever it is today. Why would I think a building made today is going to be a good building for the needs of people 100yrs from now?

Retric 6y ago
Many old buildings where designed to be cool in the summer and warm in the winter. Often those features have been removed as historically airflow kept things cool where today you want to maintain AC. It’s something of a design failure of modern buildings where walking outside when it’s 80f is pleasant but inside you need AC at those temperatures.

barumi 6y ago

> Any building using concrete for a structure should be aiming to last at least 100 years. I don't know which country you have in mind but in Europe the construction industry by law is obligated to design concrete structures for residential buildings that ensures a useful life of at least 50 years, and by definition that means that the building structure shall not require maintenance for at least 50 years. Moreover, concrete as a widespread structural material is relatively new, and city centers are still packed with contrete buildings that were built when the technology started popping up. In fact, in general a building with concrete structure is only demolished when it's not possible to retrofit or renovate it effectively, due to unrelated reasons such as increasing occupation density that would not be cost-effective by reinforcing the concrete structure. My point is that concrete structures are not demolished with enough frequency to be of any concern. The main reason is that concrete structures are simply too expensive to be demolished, moreso in urban centers. Thus your concern simply isn't relevant in the real world because economics already impose the same restrictions that are expressed in your environmental concerns.

stjohnswarts 6y ago
Maybe in Europe, but in the United States if you want to tear down a building and build another one, there is about a 99% chance you can do that and get the paperwork for it without too many hurdles other than NIMBYs.
- barumi 6y ago
  That's an entirely unrelated issue, and fits the case of urban renewal projects whose preexisting building is not able to accommodate new functional requirements, at least in a cost-effective way. The only factor that the use of concrete plays in this scenario is that concrete structures are expensive and time-consuming to demolish. If the investment makes financial sense then the choice of building material doesn't make any difference.