By Jonny Tiernan
In building construction, there are a plethora of materials available that are more environmentally friendly than concrete. But when you think of what it takes to create a skyscraper, many of the alternatives just don’t fit the bill. You’d be forgiven for thinking that a highrise structure of any notable size could only be erected using concrete and steel, but with the arrival of plyscrapers, this notion is being turned on its head.
‘Plyscrapers’ are highrise buildings made almost entirely of wood. Not any normal kind of wood though, as they utilize cross-laminated timber, otherwise known as CLT. CLT panels are made by gluing together layers of softwood, and is similar to plywood only with much thicker laminations. The layers run perpendicular to each other, and the method used leads the panels to be stronger than concrete. If you’re thinking that being made from wood poses a fire risk, you’re wrong. CLT is fire-resistant, and instead of going up in flames, the material just chars.
Strong, fire-resistant and environmentally sound
The strength and fire-resistance makes CLT a great material for building with, and they can be used in a way that is much less labor-intensive than a standard concrete skyscraper. The panels can be bolted together quickly, cutting down on time and costs.
More importantly than the financial benefits, CLT is also much more environmentally sound. The production of concrete generates a high level of carbon emissions, whereas timber is coming from trees that have been absorbing carbon during their lifespan, up to the point where they are cut down to be used for the building material. The carbon is then stored in the wood, where it remains until it is burned or recycled.
The clear advantages of plyscrapers are leading to their increasing popularity across the world, but there are still regulatory hurdles to jump before there is widespread adoption. In the US, for example, the building codes in certain areas prohibit wooden structures over a certain height. When these regulations are updated we can expect to see many more of these plyscrapers reaching for the skies.
Notable plyscraper projects
When it’s finished, this 12-story structure in Portland, Oregon will be one of the tallest timber buildings in North America. As we mentioned in our earlier article, it was set to be the tallest, but that accolade is now out of reach. The project received $1 million in funding to help make sure the CLT used meets the requirements of building codes. It could prove to be the testing ground that paves the way for more future highrises. Construction work begins in January 2018, and is expected to be finished by the end of the year.
Standing at a height of 32.17 meters, this apartment building in Melbourne, Australia was the world’s tallest timber apartment building when it was constructed in 2012. It cost an estimated $11 million to build, and the use of CLT rather than concrete had the same impact on carbon emissions as taking 345 cars off the road.
This apartment block in Bergen, Norway overtook Forte as the world’s tallest timber building when it was completed, before losing the crown to Brook Commons. It is 14 storeys tall and cost around €22 million to build, including purchase of the area, development costs, engineering and construction costs, and internal costs.
This 18-storey, 53-meter tall cross-laminated building in Vancouver, Canada was finished a staggering 66 days ahead of schedule, which just goes to show that the claims being made about how CLT will speed up the construction process really do ring true. The tower is student accommodation for the University of British Columbia, housing over 400 students. It currently holds the title of the tallest timber building in the world.
Currently in the planning stage, this tower in London will easily be the world’s tallest if it makes it through to completion. It would have 1,000 units in a whopping 93,000 square meters of space, with the 80 storeys giving it a height of 300 meters.