Building future cities out of timber could save 100B tons of CO2 emissions

https://singularityhub.com/2022/09/05/building-future-cities-out-of-timber-could-save-100-billion-tons-of-co2-emissions/

by cheinyeanlim • 4 years ago

149 297 4 years ago

singularityhub.com

Iwan-Zotow• 4 years ago

that would make some spectacular burnings

MichaelCollins4• 4 years ago

Sprinkler systems and redundant fireproof stairways solve this problem.

randtrain342• 4 years ago

It actually doesn't, mass timber is extremely hard to ignite, see https://www.vox.com/energy-and-environment/2020/1/15/2105805... (advantages section)

MichaelCollins4• 4 years ago

5-over-1 buildings have been known to burn pretty well while under construction, when the building is bare timber with no fire suppression. But once the walls and sprinkler system go in, they resist fire well.

dukeofdoom• 4 years ago

Exactly! what would happen next time riots break out in the US? Potentially near entire cities burning down to the ground, if it's a windy day. The way fire spread in wood built Japanese cities like this one: https://en.wikipedia.org/wiki/Great_fire_of_Meireki

idiotsecant2• 4 years ago

Timber high rises seem somewhat dangerous from a fire perspective, surely

ericmay4• 4 years ago

That’s a good reason not to build them, and keep building heights lower so that neighborhoods, towns, and cities have a good level of density.

itake3• 4 years ago

That is basically what LA did and they ended up with a traffic nightmare.

swlkr3• 4 years ago

You wouldn't build timber high rises. You would only build buildings ~4 stories tall.

jeffbee• 4 years ago

Well, they do build tall timber buildings. The thing is they are virtually solid wood, with corresponding fire resistance ratings. I'd much rather be in a mass timber high-rise than a stud-and-cavity mid-rise building in a fire.

User232• 4 years ago

They’re called 1+5s.

voisin• 4 years ago

There are 10+ storey timber high rises in Canada now. The building and fire codes are being updated all across the country. Turns out heavy timber is actually pretty decent for fire - it chars before it fails whereas steel loses its strength at high temps.

tigerlily• 4 years ago

Mass timber structural members actually perform quite well under fire conditions. It takes quite a lot to burn through a big lump of solid wood.

UberFly• 4 years ago

Though like we witnessed with the twin towers, all you have to do is weaken them.

idiotsecant2• 4 years ago

i think the problem is that wood self-propagates fire.

Barrin92• 4 years ago

not really because the load bearing parts don't tend to burn (the same way a log doesn't because the charcoal layer eventually stops the fire). That ironically even may make them somewhat safer than concrete which tends to crack. The largest currently existing timber high rise as far as I know stands in Norway and is about 81 meters tall.

robomartin17• 4 years ago

if at least 90 percent of the world’s new urban population is housed in buildings made from wood

I put this in the category of my favorite joke with regards to physics in the classroom vs. real-world physics. It goes something like this:

"Assume a cow is a uniform sphere of milk, one meter in diameter"

Anyone who has studied physics to a reasonable depth understands the great disparity between the "assume..." constraints of classroom teaching (which are necessary to be able to learn) and what happens with real-world problems.

This is at that level. At least NINETY PERCENT? C'mon. I thought Disney was where fantasies are made for entertainment, not in scientific research.

We've just experienced several very large fires in California. Just one of these probably emits more CO2 than all internal combustion vehicles in the state in a day. I remember reading vegetation fires in California, in one year, emit the equivalent of 25% of the CO2 emitted by the entire transportation sector in the state during the same year. In other words, if internal combustion engine cars went away tomorrow, we would still produce so much CO2 from fires it would almost be pointless.

Now add to this the additional fires we would have to contend with if we plant millions/billions of trees. The fires would be larger and likely more frequent. They would probably destroy more property and wild life. And now, add to this entire cities built out of timber, rather than concrete. In other words, in a sense, storing the CO2 containing wood in a structure full of electrical wiring, gas lines, and other fire hazards.

Yes, that would be intelligent. Instead of creating less fire danger, increase it. Exponentially.

Like a I said, assume a cow is a uniform sphere of milk one meter in diameter and everything is possible.

EDIT:

The irony, of course, is that massive reforestation around the world is likely the only realistic way to capture CO2 at scale.

twawaaay3• 4 years ago

Except forest fires do not produce CO2. They release carbon that has been temporarily stored in trees and is part of the carbon cycle.

On the other hand, by driving a car, you are adding to the atmosphere carbon that has not been in the cycle.

Btw, for the same reason, neither planting trees nor building cities out of wood will do anything. It is awfully hard to preserve wood forever in any large quantities that would make any difference.

User232• 4 years ago

Except forest fires do not produce CO2. They release carbon that has been temporarily stored in trees and is part of the carbon cycle.

By that reasoning burning coal doesn’t produce CO2 either. It’s just a matter of the size of the time constant. Coal burning is just a forest fire with greater hysteresis.

robomartin17• 4 years ago

Except forest fires do not produce CO2. They release carbon that has been temporarily stored in trees and is part of the carbon cycle.

I hope you are kidding.

The planet has had multiple cycles of atmospheric CO2 increases and decreases over millions of years. We have very accurate data to cover 800,000 years, where the range was between, roughly, 200 and 300 ppm.

The question is:

How did CO2 increase when humanity was pretty much insignificant and not burning fossil fuels? How did that happen?

The answer is simple: Massive, continental scale forest fires. Without modern fire fighting and mitigation technologies these fires burned for very long periods of time and razed areas the size of entire modern cities.

The average 100 ppm increase took about 100K years. Nothing other than fires could cause this change. Fires over a very long period of time.

The other question is:

How did atmospheric CO2 concentration decrease?

After all, we were not around to "save the planet" with technology.

Also simple: Rain, hurricanes, cyclones, weather and vegetation regrowth over 100K years. That's how long it took the natural planetary engine to react to a 100 ppm change in atmospheric CO2 and revert it.

Next question:

How did humans add another 100 ppm+ in such a short period of time?

Because we burned more forests faster than nature could have ever done on its own. Except we did this by burning oil, petroleum. One way to look at petroleum is that it is a highly concentrated form of plant and other biomass materials turned into goo we can easily burn. And so, by burning it, we engaged in the equivalent of burning entire forests on a daily, monthly or annual basis for the last several hundred years. As population grew, the more we burned. And here we are.

Forest fires absolutely produce CO2. That has been the cased for millions of years. If it makes your more comfortable to say they release CO2, so be it. That's fine. The net effect is the same: CO2 accumulates in the atmosphere and contributes to global warming. Same thing cars do.

The greater point is a dark one, and one most people are not ready to accept: There isn't a thing we can do about it. It's a planetary-scale problem that will take in the order of tens of thousands of years to affect. We can't do it.

EDIT:

One more question we should ask:

How many trees (or plants) went into creating one unit of petroleum?

https://www.eurekalert.org/news-releases/654287

From the article:

    "Can you imagine loading 40 acres worth of wheat – stalks, roots and all – 
     into the tank of your car or SUV every 20 miles?" asks ecologist Jeff Dukes, 
     whose study will be published in the November issue of the 
     Journal Climatic Change.

Here's the full paper:

https://core.ac.uk/download/pdf/5212176.pdf

mcbishop3• 4 years ago

But those burned trees pulled the fire-released carbon from the atmosphere not all that long ago. ...Vs. the carbon in fossil fuels, which has been underground for literally millions of years.

robomartin17• 4 years ago

Not sure what your point might be. If you burn the equivalent of thirty years of forest growth and release that carbon it will take, I don't know, a thousand years to get it back. This isn't a 1 to 1 game. Nothing in the real world works with 100% efficiency.

Atmospheric CO2 remain in the atmosphere for a very, very long time. Thinking we can just reach out and retrieve it --at a planetary scale-- is nothing more than a fantasy being sold to make money.

blacksqr2• 4 years ago

Our path is clear. Pave over all forests and our climate change problems are over.

rascul• 4 years ago

ESR wrote something along those lines some years ago.

http://esr.ibiblio.org/?p=6607

Edit: Apparently his site doesn't say who he is anymore. https://en.wikipedia.org/wiki/Eric_S._Raymond

renewiltord• 4 years ago

Had a relative who was an executive at a timber-only structural design firm and I visited them a few times so I know a little bit more than a layman. Comments here are kinda low-brow, honestly. A little disappointed by that.

Anyway, there are all sorts of timber-based products these days. I'll pick one, cross-laminated timber, and just link a bunch of basic stuff:

- fire resistance, measured by the Forestry Service https://www.youtube.com/watch?v=HuVTCOmRGd0

- structural integrity code https://shop.iccsafe.org/mass-timber-buildings-and-the-ibcr.... (high-rises approved in the International Building Code)

- structural integrity example https://www.ascentmke.com/ 25 story building in Milwaukee (strictly uses both CLT and glulam, but well, give me a little slack)

gonzo41• 4 years ago

That fire resistance video is impressive.

bombcar3• 4 years ago

Engineered wood is really impressive and I can’t wait for it to be more common.

falcolas3• 4 years ago

They’re already used extensively. Anywhere there’s a wooden beam over 2” x 6”, not to mention plywood/chipboard/etc. old growth wood, which you’d need to make a solid beam of any bigger dimension, is waaay too expensive (not to mention less reliable/predictable) these days.

randtrain342• 4 years ago

Is CLT/NLT/glulam less weather resistant (eg. against excessive humidity/moisture) than traditional buildings though?

wahern• 4 years ago

All modern homes require active humidity management as they're sheathed with plywood externally and drywall[1] inside. Even if you use concrete or brick you still need active humidity management if you don't want mold growing on all your furniture, etc.

There's no more old growth timber to build (and furnish) homes the way they were built 100+ years ago. All the alternatives require active systems to prevent rapid degradation.

This is even true of modern towers--the types of steel, the techniques, the tolerances, the use of reinforced concrete, etc, require active systems. Towers built 100+ years ago were in some ways more resilient than today, having used materials and techniques--knowingly and unknowingly--that could hold up to the elements better with active management.

[1] Even in high-end builds, nobody except perhaps a die-hard DIY'er with money to burn uses more moisture resistant drywall variants or alternatives throughout an entire home. I once toured a 100+ year old house supposedly renovated and lived-in by an architect. They basically rebuilt the entire structure, including replacing much of the timber with steel. Everything _looked_ high-end, except the walls if you paid attention. They just used regular drywall--not the cheapest, but definitely not the nice stuff (e.g. what you might find in a class A commercial office). IIRC, the internal doors were solid core, but that hardly mattered given you could hear everything through the cheap walls.

trinovantes• 4 years ago

I'm more concerned about noise isolation

Concrete buildings seem to isolate my neighbors' noise far better than wooden structures

thewebcount• 4 years ago

Yeah, I lived in a wood frame building. The first week we were there, we heard some young kids right outside our door making noise. I opened the door to ask them to quiet down and there was nobody there. But I can still hear them. So I go up one floor. No kids, but they’re still just as audible as before. I go up one more floor to the top floor. Sure enough that’s where they were, 2 floors above us. It sounded like they were at our doorstep. Needless to say we moved out after just under a year because of the noise problems.

SECProto2• 4 years ago

When you say "wooden structures", you're referring to typical stick framed construction with likely no sound dampening or insulation. This post is about mass timber construction[1], where the (manufactured) timbers function more like a concrete or steel columns/girders/shear walls.

Many modern concrete buildings use steel stud framed walls, which are actually worse than stick framing for noise isolation.

[1] https://en.wikipedia.org/wiki/Engineered_wood

abcanthur• 4 years ago

noise transmission (and the reduction thereof) is affected by all aspects of building design. A wood building will not always be noisy. More expensive buildings tend to have multiple mitigations in place for sound transmission. These can be multiple special purpose layers in floors and walls, from elastic layers that are only a few mm thick, to inches of poured concrete present only for the sound response. A technique in very nice stick-built (the 5-over-1s mentioned) buildings is to have walls built with different structural systems for either side of the wall. Two layers of drywall on a single structural wall acts like a membrane, transmitting sound to the other side. Attaching drywall to disconnected structures greatly inhibits that vibration, at the cost of a thicker wall (lost rentable sqft) and ~2x spent on structure.

falcolas3• 4 years ago

Mass, decoupling, and air tightness are all required to isolate sound effectively. All three are expensive to implement, and spec homes (houses built to immediately sell, as opposed to live in) are all about saving money to make more profit.

cycomanic5• 4 years ago

Noise isolation is much more a function of how the actual insulation being put in. If houses are build to the lowest standard than yes they will be incredibly noisy. I mean cheap concrete apartment buildings are essentially made with large concrete frame and thin plaster interior walls.

Kaotique• 4 years ago

Except when someone wants to drill a hole to hang a painting. You can hear that multiple floors up or down. I live in a 30 story building and the drilling noise in a real nuisance.

jacknews5• 4 years ago

I think the new processes for smelting steel are carbon neutral, and steel is highly recyclable. I think it would make sense to have hybrid steel-wood buildings, using a steel superstructure. And also use MgO cement where something mineral is needed or desired, as I think that is also carbon neutral.

SECProto2• 4 years ago

We're working towards carbon neutral steel, but not there yet. Here's an article https://www.newyorker.com/news/annals-of-a-warming-planet/th...

jacknews5• 4 years ago

Yes maybe it's not quite full production ready yet, but it looks like it's very close, going by for example this https://www.treehugger.com/boston-metal-electrifies-steel-ma...

diordiderot4• 4 years ago

I think it would make sense to have hybrid steel-wood buildings

Why? What advantages do you imagine come from not using wood?

988747• 4 years ago

Steel is much stronger so you can build much bigger buildings with it. Imagine 25-stories apartment/office building with steel skeleton and wood for walls.

jacknews5• 4 years ago

I did not say not to use wood. What advantages do you 'imagine' for using wood as main supporting structures, against something already extensively used, steel?

donatj• 4 years ago

My sister lived in a very new timber apartment building on the 3rd floor.

I'm not sure if there had been a water leak or what but the whole floor of her apartments main living area notably drooped in the middle and was kind of bouncy.

She claimed she couldn't notice it but I found it really unnerving.

ocbyc3• 4 years ago

Also it allows you to participate in your neighbors arguments without even being invited over.

sparsely3• 4 years ago

This is totally untrue IME of modern mass timber buildings. The sound isolation is excellent.

kkfx3• 4 years ago

The issue with wood based homes is that they are really good for SMALL individual homes. NOT for tall buildings despite theoretically xlam and co allow to build them...

It's not only a matter of water-leaks but also of noise, low thermal mass with the need of more effective ventilation and precise heating hard to get in a large building etc.

In ecological terms it's a matter of scale: trees keep growing IF we do not cut them too much. So at a certain level of demand wood is renewable, above it's not.

In human terms pushing revolutions is not much good because anything have and EOL and if we build much in a short period of time we need to rebuild en mass when it will reach it's EOL and we do not know up front in what kind of situation we will be at that point in time. So better a slow evolution, sparse, to have backups and low "new generation" demand in the timeline...

The real points though are IMO:

- who need apartments? People or those who sell them/sell the land since selling many apartments means much more profit than single-family homes?

- how can dense city/big buildings evolve? We know that they have a limited lifecycle, however no one seems to care up-front about it. Single family homes with a bit of land around can be rebuilt for instance at a generational change, it's easy to reach the decision as a single owner with a single family impacted, it's nearly impossible with MANY families in a single building.

- can dense area evolve well? For instance few decades ago cars was not that spread, so cities was not built for them. Cars arrive. Dense cities have struggled enormously to add them and nowadays we mostly agree that in dense are the sole option is public transports for nearly all since there is no physical place for cars for all. Cities built for cars for all on contrary struggle to maintain their road networks, their economy need a continuous growth witch works ONLY until old infra reach their EOL. Again not evolutionary plans was made up front. We are talking about flying cars nowadays, where to land tomorrow? We have seen the shift from shopping centers to on-line retails where to adapt to receive large boxes when we are not at home in a tall building? Spread enough single-family homes with small scattered buildings for work/service purpose on contrary CAN evolve. No matter much if we foresee well or not.

Well... IMVHO cities have reached the point of "too much density", there is no more economy of scale in them respect of their many issues. We still need a bit of density, we still are social animals, but instead of evolving toward bigger and bigger dense area, hubs in the middle of nothing, we need to spread, in a partially interconnected and mixed network. Like who? The classic internet vs today's one? In the end actual research shows that "any kind of network" tend to behave similarly... And those seems to be lessons no one want to take...

BurningFrog2• 4 years ago

People or those who sell...

Those who sell apartments are also people!

cycomanic5• 4 years ago

It seems a bit like you are just making stuff up without evidence to back this up. Many of the supposed issues have been solved ages ago.

The issue with wood based homes is that they are really good for SMALL individual homes. NOT for tall buildings despite theoretically xlam and co allow to build them...
It's not only a matter of water-leaks but also of noise, low thermal mass with the need of more effective ventilation and precise heating hard to get in a large building etc.

Sure at the moment nobody builds sky scrapers from timber, but large apartment buildings are absolutely no issue e.g. https://www.arup.com/projects/haut Moreover while you are correct that they tend to have lower thermal mass, they can typically be build much better insulated and air tight. Many low energy houses both small and big are timber houses. Heating and ventilation is not a bigger issue compared to concrete houses and noise is much a function of insulation so typically modern timber houses are better because they get build to a higher insulation standard.

In ecological terms it's a matter of scale: trees keep growing IF we do not cut them too much. So at a certain level of demand wood is renewable, above it's not.

What is your point? you can always grew more trees if the demand is higher. The issue is not just that timber is renewable, its also that building based on timber is extremely CO2 and energy intensive.

In human terms pushing revolutions is not much good because anything have and EOL and if we build much in a short period of time we need to rebuild en mass when it will reach it's EOL and we do not know up front in what kind of situation we will be at that point in time. So better a slow evolution, sparse, to have backups and low "new generation" demand in the timeline...

I don't know why you're bringing this up in this context, nobody is proposing to tear down cities and rebuild with timber.

The real points though are IMO:
- who need apartments? People or those who sell them/sell the land since selling many apartments means much more profit than single-family homes?

? how about the people living in the apartment buildings. Building cities from single family homes is completely unsustainable. the land use, transport cost and building costs are extremely high.

- how can dense city/big buildings evolve? We know that they have a limited lifecycle, however no one seems to care up-front about it. Single family homes with a bit of land around can be rebuilt for instance at a generational change, it's easy to reach the decision as a single owner with a single family impacted, it's nearly impossible with MANY families in a single building.

? You make it sounds like cities are a new phenomena. We have build cities for hundreds of years, this is a solved issue. Moreover an advantage of apartment buildings over individual homes is that they typically lasts longer. We do not want to rebuild our housing every 30 years or so.

- can dense area evolve well? For instance few decades ago cars was not that spread, so cities was not built for them. Cars arrive. Dense cities have struggled enormously to add them and nowadays we mostly agree that in dense are the sole option is public transports for nearly all since there is no physical place for cars for all. Cities built for cars for all on contrary struggle to maintain their road networks, their economy need a continuous growth witch works ONLY until old infra reach their EOL.

Yes building cities for cars makes them very unlikeable, how about we stop? Also blaming this on cities is a bit rich, the issue is that we suddenly changed our transport method to cars, which got us into the mess we are in. But importantly, you completely omit the fact that we can't have modern rural living without cars, so the costs are much higher (both in terms of energy and money). Rural living is completely unprepared for cars to disappear.

Again not evolutionary plans was made up front. We are talking about flying cars nowadays, where to land tomorrow? We have seen the shift from shopping centers to on-line retails where to adapt to receive large boxes when we are not at home in a tall building? Spread enough single-family homes with small scattered buildings for work/service purpose on contrary CAN evolve. No matter much if we foresee well or not.

Funny, what you describe is largely suburbia, which has lots of sustainability issues (you need a car to get around, typically not walkable... )

Well... IMVHO cities have reached the point of "too much density", there is no more economy of scale in them respect of their many issues. We still need a bit of density, we still are social animals, but instead of evolving toward bigger and bigger dense area, hubs in the middle of nothing, we need to spread, in a partially interconnected and mixed network. Like who? The classic internet vs today's one? In the end actual research shows that "any kind of network" tend to behave similarly... And those seems to be lessons no one want to take...

So how would this work, how are you proposing to spread out cities like New York, Tokyo or London? I mean you can look at cities like LA or Melbourne to see what happens if you restrict density of housing to largely single family dwellings. The cities become huge in terms of land area. Gridlocked as everyone has to travel large distances and making extensive public transport networks is much more difficult.

brnt• 4 years ago

CLT.

noobermin2• 4 years ago

The article is talking about mass timber which is a building type that is still pretty uncommon in the US but is emerging in Europe mostly. If you (and she) are American it's likely just a wood frame building.

d0gsg0w00f2• 4 years ago

What your sister experienced was just good old fashioned bad craftsmanship which will happen in concrete buildings too.

AstralStorm7• 4 years ago

Soviet buildings were the epitome of bad craftsmanship. Most of them are around so far...

skybrian3• 4 years ago

They mention mass timber, but lots of buildings in the US already use wood framing, and 5+1 apartment blocks (with the top 5 floors using wood framing) are going up everywhere.

noobermin2• 4 years ago

Mass timber is a specific type of building type which is distinct from wood framing. From this[0] article:

If the primary load-bearing structure is made of either solid or engineered wood, it’s a mass-timber building. A building that uses mass timber as an accent and not a primary structural element isn’t mass timber.

[0] https://www.constructiondive.com/news/mass-timber-101-unders...

skybrian3• 4 years ago

Yes, I agree. I think mass timber is only used in fancy commercial or institutional buildings, though? So it seemed worth pointing out the more common, ordinary kind.

It seems doubtful that "future cities" will be primarily skyscrapers when quite high densities can be achieved with buildings that don't go above five stories or so and are cheaper to build.

sparsely3• 4 years ago

Here's a very interesting video of a Euro mass timber building highlighting some of the differences: https://www.youtube.com/watch?v=bZGuSC7KNvM

credit_guy3• 4 years ago

For context, humanity produces about 50 billion tons of CO2 emissions per year. This estimate of 100 billion tons is between now and 2100, so about 1.2 billion tons per year savings. That's not nothing, but it's not that impressive either. And if it turns out the assumptions in the estimate are a bit optimistic, then it becomes more or less a rounding error.

ido• 4 years ago

2.4% savings in emissions is massive. It obviously not on its own the only measure we need to take.

shepherdjerred3• 4 years ago

It’s a drop in the bucket compared to the other changes we need.

Of course we can do things in parallel, and I’m not saying this isn’t worth doing, but this is one of the least important things we could do to curb emissions.

tut-urut-utut• 4 years ago

The impact of cutting a military budget worldwide to half of today's spending would bring up to 8% percent.

If we still need to have wars worldwide, why not take a look at the current China India conflict as an example. There they agreed to fight only with sticks and clubs, and it's working great for both sides.

nextaccountic• 4 years ago

That's not nothing, but it's not that impressive either.

Almost all initiatives fighting carbon emissions are on the low % percentages. That's just the nature of the problem.

If humanity wants to stand a chance, we need to catch ALL the low hanging fruits

qeternity3• 4 years ago

The problem with decarbonization is that there isn’t any low hanging fruit.

At its core, hydrocarbons are the best source of energy at this moment, ignoring emissions. And the emissions problem is a massive tragedy of the commons.

So you have a need to drive behavior towards something suboptimal with incentives that benefit those who don’t change behavior.

lozenge• 4 years ago

...and many of the high hanging ones too!

philjohn2• 4 years ago

And we've seen examples from other domains where 1% here, 0.5% there adds up to meaningful gains (I'm talking of the marginal gains philosophy of UK cycling, and then Team Sky).

If we write off every "This will only help 1%" then you ignore that in combination the effect is magnified.

credit_guy3• 4 years ago

Replacing coal with natural gas has huge impact. It was probably the main driver of the reductions in emissions in the US for the last 15 years. Natural gas will continue to displace coal, so additional emissions reductions will be had.

Solar and wind electricity generation also have a huge impact; they account for 10% of the electricity generation in the US now, but 20 years ago they accounted for roughly 0. The increase of solar generation was above 20% per year each year of the last decade (except one); wind grew at maybe about 10% per year. It's not likely that they continue at the same rate, but even if they grow at only 15% and 5% per year for the next 2 decades, the impact will be huge.

We can get to a point where we only have solar, wind, hydro, nuclear and natural gas. The natural gas will be the most economic way to deal with the intermittency of solar and wind. Then we'll switch to hydrogen. Then we'll decarbonize steel and concrete. We'll actually start doing that in parallel. Once concrete is decarbonized, there's no point in wooden buildings.

badpun• 4 years ago

If humanity wants to stand a chance,

Why is it so commonplace now to conflate climate change with basically armageddon? I thought that most models predict some hard times (mass migrations and everything bad that comes with it), but species extinction (or even, civilization collapse) is still a fringe belief among the scientists.

BurningFrog2• 4 years ago

"This one trip to the gym is not going to make me super fit, so going is pointless!"

shepherdjerred3• 4 years ago

Consider how common it is for a person to treat themself to a 300cal donut because they burnt 200cal on a run the previous day.

AstralStorm7• 4 years ago

The better question is how long will these buildings survive before major structural rework (razing them and rebuilding from scratch).

Some of ye olde concrete prefabs are standing now for over a century. As are brick buildings.

It could be fixed by turning wood into polymer reinforced wood, but that is an entirely different building method, closer to brick.

shepherdjerred3• 4 years ago

I had a civil engineering friend who worked for a firm that specialized in wooden buildings (the proper name escapes me, but think office buildings made of wood?).

According to him it’s very in demand, and it can rival traditional building methods.

herbst3• 4 years ago

I live in an old wood house that was built 200-400 years ago. I only know because my neighbor's house looks identical and is built around 1640. No structural things have been changed, only internal renovations and addons.

I was surprised myself. Even more so when you hear that most old concrete or brick town houses have been either destroyed and rebuilt or structurally renovated in the last 40 years or so.

beachy• 4 years ago

My house was built in 1905, all wooden frame. The timber is in perfect shape and as long as there are no leaks, will last for another hundred at least. It becomes very hard though and difficult to nail into. I would imagine wood has more longevity under the right (dry) conditions than steel.

cycomanic5• 4 years ago

I live in Sweden,there's plenty of wooden houses that are hundreds of years old. How long a building lasts is much more a function of other factors, not the building material itself.

WastingMyTime892• 4 years ago

Provided we don't let the timber rote outside or burn it, having to rebuild regularly could actually be a good thing.

fyvhbhn• 4 years ago

8 billion per year could be saved just by eating less meat: https://www.nature.com/articles/d41586-019-02409-7

Imagine what could be saved being vegan

jjallen• 4 years ago

This would be a great solution, if we could reliably prevent them from going up in flames, for two obvious reasons.

How many times have we heard about [old-town] burned in [year]? This would happen again negating any environmental benefits and obviously costing a ton of money to rebuild.

Maybe if we could get the burn rate down to 1% a year it would be a benefit?

viraptor• 4 years ago

I don't think that really applies here. The article concentrates on replacing cities and concrete with timber. Old towns burning down have different issues than downtown office buildings.

Also in general, processed timber can be made more fireproof than many usual materials.

herbst3• 4 years ago

I am not sure why. But this is really uncommon here in Switzerland. Sure sometimes there is an old house burning down somewhere but nether do we talk about spreading fires nor do I have to pay more insurance for living in a 100% wooden house.

akvadrako• 4 years ago

That isn't a problem with CLT, which is so dense it usually just chars the outside. Only at temperatures that could destroy concrete and steel buildings does it really burn.

blippage• 4 years ago

Great Fire of London 2.0

mschuster912• 4 years ago

For what it's worth: wood actually has better properties in the case of a structural fire than today's usual stuff - it gradually loses its rigidity, compared to the iron in reinforced concrete which suddenly snaps [1].

[1] https://www.hilti.de/content/hilti/E3/DE/de/business/news-un...

notahacker• 4 years ago

On the other hand, the reinforced concrete itself isn't combustible, and gradually losing rigidity whilst burning isn't exactly a desirable structural property. And building entirely from timber implies using a whole lot of combustible woods, not just glulam beams. (Then again, this is pretty standard practice in housing anyway...)

Construction solely in reinforced concrete might be undesirable for other reasons, including environmental impact, but does tend to isolate household fires so they burn themselves out long before the structure is threatened

rsecora• 4 years ago

Not enough timber in the world. There is a risk of deforestation and ending as Easter Island inhabitants.

mauvehaus• 4 years ago

I have an Outside In episode for you[0]. Turns out, the inhabitants of Rapa Nui didn't clear-cut the island to build the moai.

[0] https://www.nhpr.org/environment/2021-10-21/outside-in-rapa-...

deepdriver• 4 years ago

Rammed earth is more abundant, potentially cheaper, and has far better sound and thermal insulation properties:

https://www.bbc.com/future/article/20220705-the-sustainable-...

It is more labor-intensive but easily automated, at least one start-up has worked/is working on this:

https://www.youtube.com/watch?v=4TXj5IIkUIY

Rammed earth panels can also be prefabricated and delivered to build site via truck:

https://www.youtube.com/watch?v=WFddMSRel4A

The city of Shibam in Yemen shows how a high-rise rammed earth/adobe city might look. It's possible to adapt this technique to wet climates with appropriate plasters and maintenance:

https://www.youtube.com/watch?v=zm8OGIZ7tag

jaclaz• 4 years ago

Past thread about rammed earth:

https://news.ycombinator.com/item?id=32042797

pelasaco2• 4 years ago

Sure, 2020/2021 the prices of Timber exploded due higher demand. This variable is simply not taken into account.

"And there are also big question marks over the safety implications of shifting to predominantly wood-based construction. While the paper states that engineered wood is “associated with fire resistance,” the jury is still out on whether it is truly as safe as traditional building materials."

Not just that. Aging and Maintenance, warping, pest infection and other benefits from concrete like durability, energy efficiency...

I guess the authors never read the 3 little pigs. You just need a Wolf with some Howitzer trying to free your country from the West, to you understand the advantage of Concrete vs Timber..

vpilcx• 4 years ago

Alright, engineers, let's reference that seminal work: 3 Little Pigs.

pelasaco2• 4 years ago

I just used this seminal work to make clear why people build houses/castles and walls from concrete and not from Timber/Lumber...

lordswork18• 4 years ago

Sure, 2020/2021 the prices of Timber exploded due higher demand. This variable is simply not taken into account.

Indeed, the article ignores costs entirely. According to a 2020 study, mass timber buildings costs 2.4-12% more than concrete buildings over their lifetime[1]. That said, if carbon emissions were taxed to account the destruction they cause to the world (and consequently the global economy), I bet wood timber buildings would be way cheaper to build, even in the middle of supply shortage like we saw during the pandemic.

[1] https://www.fpl.fs.usda.gov/documnts/pdf2020/fpl_2020_gu001....

ETH_start• 4 years ago

This seems like a bad idea..

ACV001• 4 years ago

Cut the trees to save CO2 emissions. Somebody forgot that trees consume CO2 themselves and if this type of housing gets adopted widely, some companies will not wait for 10-20 years for the planted trees to grow, but will look for less ethical sources like existing wild forests.

gtvwill• 4 years ago

May I introduce you to Forestry Corp NSW.

https://www.abc.net.au/news/2022-09-07/anti-logging-protests...

s8s8discourse2• 4 years ago

Trees only have a finite lifespan. Even "wild" forests reach end of life stage and that's when responsible logging and forestry management can promote healthier forests.

Using those trees sequesters the captured carbon into structures. Leaving them to stand and die in the forest releases that captured carbon.

Gravityloss3• 4 years ago

Trees can grow over a century and stay up for centuries. Large old trees over here have scars from multiple survived forest firest etc.

Cutting down a 50 year old tree and putting it to a building instead of letting it grow is not an obvious carbon sink to me. The branches might be used for energy nowadays, but the bark and roots will release CO2 etc. The new sapling will grow very slowly (kg carbon per year) for the first 15 years.

Ironlikebike2• 4 years ago

Trees only have a finite lifespan. Even "wild" forests reach end of life stage and that's when responsible logging and forestry management can promote healthier forests.

I absolutely agree with you.

In the book "A Landowner's Guide to Managing Your Woods" the authors point out that the fragmentation of contiguous forest parcels into small private holdings is problematic when it comes to managing healthy forests in the US, especially in the Eastern part of the United States.

The book points out that in 2006 the United States grew 26.7B+ cubic feet of new timber, but has only harvested 7.6B cubic feet. The reason being that much of that acreage is not accessible to harvest.

Many small land owners of forest properties are reluctant to harvest mature trees due to conservation messaging in earlier decades. They often also manage the mature stands of forest in their small parcel for their pleasure, not for 'forest health' or optimal carbon sequestration. Imagine anyone buying a shoreline cabin property and then electively cutting down all of the mature trees on the property.

Secondly, and more importantly, many foresters can not economically harvest from small acreage/parcels. Unless many nearby land owners band together to have their forests managed at the same time, it doesn't happen.

I'm guessing that most dead-stand is going up in smoke (literally turned into firewood) because it has no utility as lumber once it has started to rot or is attacked by parasites.

For larger contiguous tracts, some counties in the US States will tax-incentivize property owners for adopting a forest management plan (that includes timed harvests of mature trees).

Some US states are also purposely expanding public forests to increase contiguous holding and close gaps (of private ownership). The goal is not necessarily to expand the boundary, but rather the consolidate the holding within the existing boundary to incentivize large tract harvest (among other reasons).

Land owners who are managing habitat for hunting are often proactively, positively harvesting (by bringing in logging companies to make clearings). Cervidae (deer, moose, elk) need contiguous stands of immature trees for habitat.

Leaving them to stand and die in the forest releases that captured carbon.

I own a stand of mature oaks that are quickly succumbing to oak wilt. They are being naturally replaced by aggressively spreading sugar maple, which can propagate quickly in a shaded understory and then bolt up when the dominating oaks die off due to disease.

I've been turning the dying mature oaks into lumber and firewood. If they're too far gone, they have no utility other than as firewood. I'm considering pre-emptive salvage in the areas that the oak wilt is prevalent so they're not completely relegated to firewood.

dusted• 4 years ago

This needs to be strictly strictly controlled.. It'd be excellent if we could use something like genetic manipulation, both to improve the material, and also identify it as being grown specifically for building.

Building material, CO2 scrubbing and CO2 storage, all in one package. Awesome stuff.

replygirl• 4 years ago

concrete puts out around 180kg per ton. a pine tree planted for harvesting lives about 20 years, will absorb 100-300kg in that lifetime, will supply more material in both weight and volume, and when processed into CLT that material will be much stronger per unit weight.

let's be generous to concrete and say we're only absorbing 100kg per 20 years, only get one ton of material, and that CLT is only twice as strong as concrete (it can be ~5x or higher in some cases). this still means one tree will have a 640kg advantage over concrete for the same output.

if we're even more generous to concrete and assume _only_ timber has wildly inefficient production and construction methods, the advantage is still in the order of hundreds of kgs.

JoeAltmaier• 4 years ago

Has the sand issue been resolved? It'd been reported that we're running out of sand suitable for concrete.

Yes, I know, "Sand? Are you crazy? The world is full of sand!". But river-polished coarse sand is no good for concrete. It has to be of a particular size and roughness to be any use. And the easy sources had run out.

Sure, you could find a process to 'make sand'. But it by definition is more expensive than 'drive a truck to where the right kind is lying on the ground and load it up'. So the price of concrete went through the roof.

The 'age of concrete' may be over. So this issue may be moot.

AstralStorm7• 4 years ago

Lime is even more of a problem than sand. We cannot cheaply or energy efficiently make it.

aaasss333• 4 years ago

How about bamboo?

jschveibinz• 4 years ago

Some parameters to consider in the discussion:

1. We need buildings to live in

2. It takes materials to make buildings. What are the potential materials?

   A. Wood

   B. Metal

   C. Concrete

   D. Soil

   E. Rock

   F. Plastic

   G. Ceramics (brick)

   H. Others?

3. It takes energy to process materials for construction.

4. It takes energy to construct buildings.

5. Energy sources:

   A. Sun

   B. Wind

   C. Water/Ocean

   D. Nuclear

   E. Fossil fuels

   F. Others?

6. Other parameters? e.g. cost, speed, labor, quality, durability, aesthetics, etc.

If one takes all of the parameters into consideration, a model (with weighting) can be developed and one can attempt to optimize the model for either net CO2, or convenience, or whatever. It's a decision problem.

Calling all math/physics/engineering folks in this forum: please propose a way to help figure this out. And thank you.

throwaway7875442• 4 years ago

You forgot politics in your parameters, arguably the single biggest factor in building.

giantg23• 4 years ago

And personal preferences. People wanting bigger, fancier houses/condos/etc are a huge factor.

blueflow4• 4 years ago

Production of Concrete releases quite much fossil carbon (8% of all emissions), and you can't fix that with renewable energies. Growing wood does not require extra energy aside from Sunlight and sequesters carbon from the air. Switching from concrete to wood would surely make a big difference.

peteradio3• 4 years ago

Isn't concrete neutral over its lifetime? Surely you'd want to take into consideration that wood an concrete are different materials?

jannw• 4 years ago

Many cities were originally built mostly in wood (e.g. London, Amsterdam). There's a good reason that they aren't any more. They burnt down - quickly and spectacularly. Typically laws were then made to require only re-building in stone e.g. After the great fire of London "The Rebuilding of London Act 1666 banned wood from the exterior of buildings"

danielfoster• 4 years ago

Modern timber buildings have superior fire resistance. I am sure sprinkler systems and fire hydrants have changed the equation since 1666, too.

throwaway7875442• 4 years ago

Timber isn't the answer. The system is complex, and we need holistic solutions, not single-factor ones.

I think the answer is to stop building so dense, reduce our population, and reintroduce more nature to our deforested, inefficiently farmed, overly-paved modern world.

The more we have 12-story buildings, the harder they are to build and maintain. 3 and 4-story buildings are much easier, can be made with timber easily, etc. But we need to spread them out more. This would be good, as we could create more small businesses to service the people, less dense areas would require less intense civil management, communities would be smaller and more familiar.

The more people we have, the worse things get. You need more homes, cities get more dense, you require more resources / food / consumer goods / land, create more CO2. Quite simply, we have a shitload of people, and that causes us all kinds of headaches. If we just had fewer people, we'd have fewer headaches. We don't need to live like bunnies/rats/cockroaches constantly multiplying. And quite frankly, the planet would do much better with fewer of us.

We would also thrive more in a world closer to nature. You notice how there's fewer insects, fish are mostly disappeared, invasive species are rampant, and cities are increasingly hot and polluted? Most of that changes if we undo most of our "developing" and let nature come back. Replace concrete sidewalks with forest trails, grass lawns with trees and weeds and bushes. Remove [at least] half the roads and replace them with canopy and gardens. Grow only sustainable multicultures of foods on a quarter of the existing farmland (and stop growing so much fucking corn!) and pay a decent wage to work the land. Bring rivers and streams back. You will notice cities get cooler, biodiversity increase, CO2 emissions decrease, and our health will improve. Not to mention fewer car accidents, less noise pollution.

pnutjam• 4 years ago

OK, now show your work where you propose a solution that ends in "fewer people". Where do all those extra people go?

devX3• 4 years ago

I'll take the massive concrete bunker in my concrete house over any wooden structure as I'm way to close to Russia.

vidarh• 4 years ago

And it doesn't need to mean low density housing.

This is a ~80 meter, 18 storey hotel built out of wood:

https://prismpub.com/mjosa-tower-brumunddal-take-title-world...

https://thetravelbook.world/2020/10/17/wood-hotel-brumunddal...

(It's also on booking.com; search for the location "Brumunddal" and/or "Wood Hotel")

BiteCode_dev• 4 years ago

Provided we grow as much as we cut, and let the ecosystem regenerate where we cut. Which is a huge if.

egberts1• 4 years ago

Sounds great except for that marginal gain and perhaps a pending doom by “Great Fire of London”.

https://en.wikipedia.org/wiki/Great_Fire_of_London

enviclash• 4 years ago

I have heard a lot of propaganda against this, without a clear or solid basis, from professionals in the industry.

theptip• 4 years ago

Nonetheless, the researchers admit that there is still likely to be some impact on biodiversity due to the replacement of virgin woodland with timber monocultures.”

Is there something preventing us from replenishing the natural woodland after harvesting wood without making it monocrop? Presumably it’s more expensive to thin out an area vs. just clearcutting. But even then if you just cut blocks inside a larger area and replant the trees, won’t everything else come back too?

Building future cities out of timber could save 100B tons of CO2 emissions

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