With Canada’s British Columbia doubling height limits for wooden buildings in July last year, and plans revealed for the world’s tallest timber skyscraper to be built in Tokyo, timber structures are becoming more and more common across the world. It is, therefore, important to examine the benefits of this alternative to conventional building design.
Logging old-growth forests has long been a contentious topic, due to their roles as critical ecosystems, home to some of the oldest and rarest trees. Despite having locked heads with protestors for decades, forestry companies continue to clear-cut these forests. This is largely due to the resultant wood’s strength, texture, and aesthetic appeal, rendering it a highly lucrative industry. However, clearcutting old-growth forests can lead to increased fire risk and removes some of our most effective carbon sinks.
The property industry has long been responsible for a huge carbon footprint and faced calls for accountability (for more information, see this previous blog post: https://about.built-id.com/features/real-estate-in-the-face-of-the-climate-crisis/). However, the timber that architects propose is used for their tower designs does not contribute to these clearcutting practices. Instead, the huge beams and columns are created from a mixture of many smaller pieces, presenting a more sustainable solution in this era of climate crisis whilst also mimicking many of the characteristics that make old-growth wood so coveted, namely strength. John Innes, dean of forestry at the University of British Columbia in Vancouver, said: “A lot of that [old-growth] wood is simply converted into relatively small dimensional lumber, which could easily be replaced by other sources. Engineered wood has provided the opportunity to actually back off the harvesting of old growth.” When produced consciously and sustainably, harvesting younger wood for this use can protect integral old-growth trees.
Timber buildings are commonly, and mistakenly, thought of as a fire risk and less stable than more conventional alternatives. However, the wood used in such towers is cross-laminated, making it suitable for even Sumitomo Forestry’s planned 350m skyscraper in Tokyo, the city most at risk of earthquakes in the world. Concrete produces up to 8% of the world’s total carbon emissions and is the world’s most commonly used material, other than water, responsible for 85% of the Earth’s mining. In contrast, timber can store carbon due to CO2 from the atmosphere being absorbed during the trees’ lifetimes, potentially even more than would be emitted via manufacture, thereby presenting the opportunity to drastically reduce the industry’s carbon footprint. Further to this, engineered wood is lighter and more efficient than other building materials, making it less likely to bow or break.
Dr Michael Ramage, Director of Cambridge’s Centre for Natural Material Innovation, has said: “We believe people have a greater affinity for taller buildings in natural materials rather than steel and concrete towers. The fundamental premise is that timber and other natural materials are vastly underused and we don’t give them nearly enough credit. Nearly every historic building, from King’s College Chapel to Westminster Hall, has made extensive use of timber.” It is, therefore, clear that a return to timber buildings, updated for the needs of 21st century society, presents an exciting opportunity for the property industry to reevaluate its current modes of operation.