In many parts of the world, wooden construction is limited to the garden shed. However, in Canada, architects have now put the good ol’ garden shed on steroids.
In some jurisdictions across Canada, wooden construction is still limited to four storeys, but in 2018, Ontario code revisions allow wood-framed residential and office buildings up to six storeys. While this is almost 10 years behind similar code changes in British Columbia, it’s definitely a step in the right direction, and a sign that wooden construction can be more than simply lakeside homes and skiing chalets.
Benefits of wooden construction
Analysts estimate a 10-15 percent price advantage for wood over traditional materials. Considering its plentiful supply of lumber, Canada is in a good position to use these code changes to its advantage.
The benefits of these code changes can’t be overstated. The average price of a condominium in Toronto is $515,578 and in the city of Vancouver—$775,806. Hence more mid-rise residential and mixed-use buildings will provide much needed affordable housing for city residents.
The benefits for residential construction are clear. Cheaper materials + fewer height restrictions = more affordable housing. But what about I.C.I. construction?
While we’re not likely to see a seven-storey log cabin any time soon, advances in technology allow architects to look at wood as a viable material for large-scale construction.
High-strength cross-laminated timber (CLT) beams now have load-bearing capabilities for multi-storey applications. Prefabricated sections provide economies-of-scale and a smaller carbon footprint.
Offsite manufacturing ensures exact specifications can be met. And we’re not only talking production specifications but also fire retardation and water ingestion.
Ironically, it’s not just technological advances that make wood attractive. Wood is warm to the touch, pleasing to the eye, non-toxic, and quite versatile. Plus, when harvested in conjunction with a replanting scheme, it’s renewable and locally grown.
How high can they go?
Here’s where the fun begins. Many countries are touting their achievements as ‘the largest wooden structure in the world’, and many are correct, simply because definitions differ around the globe.
Standing at 153 metres, the Tainning Temple in Changzhou City, China is the tallest wooden pagoda in the world. However, the 78-metre church of Săpânța-Peri Monastery in Săpânța, Romania is the tallest church in the world.
Completed in mid-2017, the 18-storey Brock Commons building on the University of British Columbia campus stands at 53 metres. With two internal concrete cores and a concrete base, Brock Commons is the tallest wooden residential structure in the world. Nevertheless, this accolade will be short-lived —in March 2019 opens the 18-storey, 80-metre Mjøsa Tower in Brumunddal, Norway.
Other noteworthy projects include:
- Forté in Melbourne, Australia. Standing at 32 metres and 10 storeys, Forté was Australia’s first high-rise timber building in 2012.
- The Cube in London, England. Barely a metre taller than Forté, the Cube stands at 33 metres and was opened in 2015. It’s hybrid wood and metal design was created by architects Hawkins/Brown.
- Dalston Lane, London, England. Completed in 2017, Dalston Lane matches the Cube in height but also has the distinction of being the largest CLT building in the world with 121 residential units.
- The Tree, Bergen, Norway. At 49 metres and 14 storeys, it was the world’s tallest until Brock Commons was opened last year.
Wood and hybrid structures
Purists will argue that hybrid projects are just that, hybrid. They’re not solely built from wood thus they shouldn’t be considered as a wooden structure.
While none could comply with such a pure definition, there are a few (notwithstanding a concrete base) that are staying true to this philosophy. 25 Kings in Brisbane, Australia could be a perfect example. The highly engineered timber structure, which opened last October, stands at 45 metres and nine storeys.
How far can wooden construction go? There are structural limitations to these plyscrapers. As buildings get taller, additional ballast is needed to counter the effects of weather. This ballast can’t be provided by wood alone, so future behemoths will likely be hybrid buildings.
Present day construction is already nearing the 100-metre mark. The next decade will see projects top 200 metres and 300 metres in the U.S. and the U.K. respectively. However, it’s the planned 350-metre, 70-floor skyscraper planned by Japanese Sumitomo Forestry Co. that will push the canopy of wooden structures when completed in 2041.