Some dramatic changes this year will have a big impact on the future of wood construction.
Last year at this time, I called 2017: The year wood construction grew like a weed. This year, I am a bit more circumspect; there were lots of steps forward, with really interesting new wood projects built, but there were also a few significant steps back. There were also what I will call steps sideways, where I am not absolutely convinced that they are steps in the right direction.
Step back: Tall wood faces troubles in Britain
We are clear that mass timber construction is not a valid target for this change and will continue to advocate for its exemption....The UK is a world leader in the development of engineered timber construction with over 500 buildings completed. As the government acknowledges this change in regulations will have an impact on the continued innovation and development of low carbon construction, and hence on the rate at which the construction industry can tackle climate change.
Step forward: Tall wood gets closer to being legal in USA
In the good news, The International Code Council (ICC) members voted in favour of building code changes that permit wood construction to a height of 18 storeys. According to Wood Business:
“Mass timber has been capturing the imagination of architects and developers, and the ICC result means they can now turn sketches into reality. ICC’s rigorous study, testing and voting process now recognizes a strong, low-carbon alternative to traditional tall building materials used by the building and construction industry,” said American Wood Council (AWC) president and CEO Robert Glowinski.
It is still not a done deal; individual jurisdictions have to approve it, and expect the steel, concrete and masonry blockheads to keep fighting it, using the UK as a precedent. But it is a very big step forward. Our earlier coverage here.
Step back: Framework Tall Wood Tower in Portland gets the chop
The Framework Tower in Portland, one of the most interesting tall wood projects on the boards, has been cancelled due to “financial considerations.” I wrote:
But really, this is a huge setback for tall wood in North America. There were so many attributes to admire in this project -- the way it was promoting the local timber, increasing density, sequestering carbon, and helping create an entire new industry around cross-laminated timber. What a shame.More in TreeHugger: Framework Tall Wood Tower in Portland gets the chop
Step forward: Other mass timber techs grab the spotlight
When the T3 building was being designed and Nail Laminated Timber (NLT) was proposed, the architect was disappointed because Cross-Laminated Timber (CLT) was the wood of the moment. However, in many cases, CLT is not the most appropriate or economical material. If you are building a new old warehouse, which is what T3 is, NLT makes a lot more sense because that's how buildings were built a hundred years ago.
Another way of holding wood together is with dowel laminated timber, or DLT. I toured the Structurecraft factory in Abbotsford, BC and really, this is the next big thing in wood. More in TreeHugger: Mass Timber is in for massive change
Step sideways: The continuing race to be the world's tallest timber tower
It may be treesonous of me to say this, but we should stop this silly competition to be tallest.
Louis Kahn famously asked a brick what it wanted to be, and it apparently responded, "I like an arch." Waugh Thistleton look at the properties of wood, and it wants to be low and wide. Rune Abrahamsen and Voll Arkitekter try to make it tall and skinny and have to load it down with concrete and tie it down with piles – just because they want to build the world's tallest building, a title it might hold for a couple of months.
Perhaps we should do a little re-think about this "tallest wood building" thing. Instead, how about designing around the people who live in them and around the nature of the material they are built from, which for hundreds of years has been low and wide, rather than tall and thin. More in TreeHugger: Yet another "World's tallest timber tower" going up in Norway
Step back: Is wood construction really as green as we think it is?
In an important article about embodied energy on BuildingGreen, Paula Melton raises some serious questions about whether our beloved wood construction is as wonderful as I keep saying it is. She writes:
But a few scientists are asking everyone to slow down, contending that LCAs have grossly overestimated the benefits of wood. “Wood is very tricky right now,” said Stephanie Carlisle, principal at KieranTimberlake and the lead developer of the Tally whole-building LCA software tool. “There is a big debate happening.” And that’s frustrating for designers who want guidance they can use. “The more we’ve dug, the more [the numbers] seem to be all over the place,” said Arup’s Yang. “There is so much uncertainty carried with them.”
We will be hearing a lot more about this in the coming year. More on TreeHugger: Why embodied carbon is so important and what designers can do about it
Step Forward: This Scottish "Baugruppe" could be the future of housing
People deserve beautifully designed and carefully built homes and neighbourhoods which promote social well-being, economic resilience and environmental sustainability. The conventional mass housebuilder form of procurement unfortunately prioritises over all these aspirations the delivery of a profit to the developer.
Although after a more recent post, I would think twice about that wood stove. More in TreeHugger: This Scottish "Baugruppe" could be the future of housing
Step sideways: Cross-Laminated Timber goes modular
There are two main ways of doing wood prefab: modular and panellized or flatpack. In modular, you get to finish the interior in the factory, but you are shipping a lot of air, you are limited to dimensions that will legally go on public roads, and there is a lot of duplication of walls, ceilings and floors.
That's one reason I was so excited about CLT; it was the ultimate in flatpack, a beautiful panel that could act as a floor or a wall, and goes together really quickly. Yet now, my CLT heroes at Waugh Thistleton are building modular CLT. I am not yet convinced it makes a lot of economic or architectural sense. More in TreeHugger: The construction revolution continues as Cross-Laminated Timber goes modular
Step Back: Tiny houses go CLT
We have also wondered what's the best way to build in wood, whether wood studs are better for small and low buildings – they are lighter, the walls are thinner, and it uses less wood.
This is a lovely tiny house, but the walls are made with 3.5 inch CLT, the same thickness as the complete wall on the MiniHome. Then it has insulation (I am assuming) and that other trendy material du jour, Shou sugi ban, on the exterior.
Trailers are supposed to be light and their walls are supposed to be thin. This makes no sense to me. More: Sturgis tiny house is built with sturdy & renewable cross-laminated timber.
Step Forward: Andy Thistleton's new book on CLT
While I continue to debate with Andy Thistleton about whether we can have too much of a good thing when it comes to wood, he is adamant and persuasive, saying the more the merrier:
The more we build using CLT, the more carbon we can store and we create a market for timber that will drive re-forestation. Planting more trees is one of the only realistic ways we have of reducing CO2 levels and it will only happen at scale if it is driven by demand. This is a critical time in the fight against irreversible climate change – the widespread adoption and growth of CLT quite literally has the potential to save the planet.
He has just published a new book, 100 Projects UK CLT, which shows the phenomenal growth in the use of wood, demonstrated in "100 hundred ground-breaking CLT (Cross-Laminated Timber) projects, demonstrating the UK’s leading position in the use of cutting edge technology to develop buildings from precision engineered timber modules."
Finally, the quote of the year about wood:
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.