High Fiber Diets Are Good for Buildings, Too

This is a series where I take my lectures presented as adjunct professor teaching sustainable design at Ryerson University School of Interior Design in Toronto, and distill them down to a sort of Pecha Kucha slide show of 20 slides that take about 20 seconds each to read. This was also presented recently at the Interior Design Show in Toronto.

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A high fiber diet is good for buildings, too.

credit: high fiber diet

A new report from the World Health Organization finds that "eating more fibre, found in wholegrain cereals, pasta and bread as well as nuts and pulses, will cut people’s chances of heart disease and early death." But it isn't just people; new research is also finding that high fibre buildings are good for our planet's health, because they significantly reduce the amount of carbon dioxide that is a byproduct of our current construction methods and materials.

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We have to stop emitting carbon right now.

credit: Waugh Thistleton Architects/ Photo Daniel Shearing

The IPCC recently reported that we have to cut our carbon output in half within a dozen years if we want to have a chance of keeping warming at 1.5°C. A more recent study concludes that this isn't good enough; Christopher Smith of the University of Leeds says that, really, we have to stop emitting CO2 right now. A professor reviewing the study tells the Guardian:

“Whether it’s drilling a new gas well, keeping an old coal power station open, or even buying a diesel car, the choices we make today will largely determine the climate pathways of tomorrow. The message of this new study is loud and clear: act now or see the last chance for a safer climate future ebb away.”

It also means that we have to stop building with anything but natural materials pretty much immediately.

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Where is the carbon coming from?

credit: World Resources Institute

As this chart shows, about a quarter of our CO2 emissions come from transportation, mostly cars and trucks on roads. About a quarter comes from heating, lighting and cooling buildings. And about a quarter comes from industry, from making stuff like steel, aluminum, concrete and plastics, most of which goes into building cars and buildings.

So, essentially, about 80 percent of our CO2 emissions come from driving from our homes to offices or whatever, and making the cars and homes and offices. So the answer is obviously to stop driving vehicles that emit CO2 and to either fix our buildings or build new buildings that don't emit CO2.

But all of those industrial emissions matter, and we have to stop making those materials that emit CO2 during their manufacture. Putting those materials into our buildings and cars creates what is known as embodied carbon.

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Embodied energy matters more than ever.

credit: John Ochsendorf/MIT

Nobody used to care much about embodied carbon or energy when buildings were not very efficient; it didn't take very long for the operating energy to blow past it as a far more significant influence. But as buildings got more efficient, that began to change; the buildings are using less energy to stay warm, so it takes far longer for the operating energy to equal the embodied energy.

And the problem with John Ochsendorf's graph is that he shows the embodied energy as being the same, in all three operating scenarios.

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Embodied carbon in structural materials

credit: Embodied Carbon

In fact, the embodied carbon and energy can vary all over the place, depending on what material you build with. Wood is very low; virgin aluminum is ridiculously high, which is why it is nicknamed "solid electricity."

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Embodied Carbon in Insulation

credit: Nataliya Lushnikova

Here is where it gets really interesting and important. They way we make high performance buildings is by adding insulation, but different insulations have vastly different embodied energies. And while a kilogram of polyurethane foam has a significantly greater insulating value than a kilogram of straw, which has to be taken into account, the fact remains that insulating a building with foam builds embodied carbon and energy into the building.

In fact, one study (which I am waiting for permission to reproduce here) has shown that, in a lifetime analysis, a highly efficient building insulated with plastic foam creates more Carbon Dioxide than a building that just meets the building code. The embodied carbon is far higher than the operating carbon right out to 2050.

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Building Green can make it worse.

credit: Nudura

In fact, even if you are a green builder saving energy by using insulated concrete forms, you are making things worse because the embodied carbon from making the foam and the concrete is probably greater than the carbon dioxide generated through the life of the building, and that carbon is all being emitted right now, instead of over the life of the building.

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Embodied carbon in cars

credit: Union of Concerned Scientists

As an aside, because this discussion is about buildings, electric cars have a significant embodied energy. As in buildings, nobody thought much about it because compared to gasoline cars the total energy consumed is significantly less, particularly with a clean power grid. But an electric car has a higher embodied carbon than a gasoline car, and still has a big footprint because of it.

It is obvious looking at this chart that driving an electric car is a huge improvement over a gas powered car, even with dirty electricity. But you cannot ever call it a zero carbon vehicle.

This is the main reason we are so big on bikes.

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Embodied carbon in Aluminum

credit: Norsk Hydro

So what can we build with? A lot of people think that aluminum is OK because so much of it is recycled, and virgin aluminum is mostly made with hydroelectric power. But there is not enough recycled aluminum, so we keep making new stuff. There is a lot of dirty and carbon-intensive stuff happening before it even gets to the electric smelter, and the chemical reaction that happens when you put electricity through alumina (aluminum oxide) strips the oxygen and reacts with the carbon anode, making, you guessed it, carbon dioxide.

It is in the chemistry: carbon dioxide is a byproduct of making aluminum.

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Embodied carbon in steel

credit: Zephylewer on Pixabay

Steel not only produces CO2 from burning coal and coke, but iron is reduced to steel by sticking an oxygen lance into the converter which combines with the carbon in the iron, converting it to carbon dioxide.

It is in the chemistry: carbon dioxide is a byproduct of making steel.

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Embodied Carbon in cement

credit: FRANCK FIFE/AFP/Getty Images

Then of course, there is cement, which is made by heating limestone to 1450 °C, which frees carbon dioxide from the calcium carbonate to make calcium oxide, which is mixed with gypsum to make portland cement. There is the energy to heat it and the CO2 released.

It is in the chemistry: carbon dioxide is a byproduct of making cement.

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Embodied carbon in wood

credit: Province of British Columbia/ forests dying from pine beetle

Then there is wood. It is the only building material where the carbon is not emitted during its manufacture, but is absorbed. It takes carbon out of the air and hydrogen out of the water to make a hydrocarbon building material. As the Cryptonaturalist described it:

If you write out the basic facts of trees, but framed as technology, it sounds like impossible sci-fi nonsense. Self-replicating, solar-powered machines that synthesize carbon dioxide and rainwater into oxygen and sturdy building materials on a planetary scale.
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Comparing materials

credit: Comparison of construction

In fact, by whatever criterion you choose, wood construction has a lower footprint than steel or concrete. Every time you build out of wood, you are storing carbon; every time you build out of steel or concrete, you are adding carbon dioxide to the atmosphere. Every time you demolish a building and replace it with a new building, unless that new building is carbon negative, you are adding carbon dioxide to the atmosphere.

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Ban demolition

credit: Union Carbide Building/ ESTO

This is why the demolition of perfectly good buildings like 270 Park Avenue in New York should be stopped; replacing its 2,400,352 square feet would generate about 192 million kilograms of carbon dioxide just replacing the steel and concrete of the existing floor area. It is a carbon crime.

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High fiber insulations

credit: Modcel Panel

This is why we have to look at alternative insulation materials with low embodied carbon, like straw, cork and cellulose and have to forget about foamed fossil fuels. As Bruce King notes in his book The New Carbon Architecture, it is the only way that buildings can help, rather than hurt.

We can structure any architectural style with wood, we can insulate with straw and mushrooms... All of these emerging technologies and more arrive in tandem with the growing understanding that the so-called embodied carbon of building materials matters a great deal more than anyone thought in the fight to halt and reverse climate change. The built environment can switch from being a problem to a solution.
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Learn from Norway

credit: Powerhouse Korbo/ Snohetta

This is why we have to build like Snøhetta did with Powerhouse Kjørbo and with their other, newer Powerhouse buildings: first, you renovate instead of building new like they did with this one. It is much harder with a new building, but they have managed to design houses, schools and office buildings that not only generate more energy than they need to operate, but "generates more energy than what was used for the production of building materials, its construction, operation and disposal." PassiveHouse is for wimps; the Powerhouse standard is crazy tough. And these Norwegians do it in the dark. See also:

Svart, a gorgeous hotel by Snøhetta, will meet the world's toughest energy standard

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Learn from the Enterprise Centre

credit: Architype Architects/ My favourite low-carbon building

This is why every architect should be studying the Enterprise Centre at the University of East Anglia, which uses a mix of new wood technologies inside, along with a combination of traditional technologies like thatch and reeds. It is built to Passive House energy efficiencies out of natural materials.

Gareth Selby, an associate at Architype and passive house designer on the project, says: "Life cycle carbon was one way to sum up the operational carbon and the embodied carbon. Everything was assessed with that attitude rather than just looking at how good is it for passive house. It was bringing the two together."

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An edible palette of materials

credit: Architype

A few years ago I wrote that we should start thinking about buildings like we do about food – using natural, healthy materials. I wasn't even thinking about embodied carbon.

"I think we have to learn from what has happened in the food movement. That's the way people are going; they want natural, they want local, they want healthy and they reject manufactured chemical products. Twenty years ago every food manufacturer talked about the benefits of technology: Transfats make food cheaper and better, high fructose corn syrup has all kinds of advantages. Now even the biggest companies run from these, the vinyls of the food industry.

We are never going to get rid of all these chemicals and plastics from green buildings, any more than we are going to get rid of all additives from food. Some have very useful functions and some, like vitamins in our diet or plastic sheathing on electric wiring, are even good for us. That doesn't mean that we shouldn't try to minimize their use and, where there are healthy alternatives, choose them instead. I suspect that pretty soon that is what your clients will be demanding."

Now, more than ever, we have to think that way. We just have to stop using materials that are made with or from fossil fuels and that add carbon to the atmosphere. We have to subtract it. We have to do a life-cycle analysis to ensure that our choices help the planet, not hurt it.

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We can build almost anything in low carbon materials.

credit: Dirk Lindner

We can still build big beautiful buildings, offices and apartments. We just don't need to build them forty stories high, but we do need to build them to be carbon positive. And we have to start right now.