By Jemma Powell | Science Editor
When discussing reducing our carbon emissions for climate change, we tend to focus on areas such as travel and consumerism. However, with the annual production of cement accounting for 8% of global emissions (more than aviation), perhaps we should question construction too. Unbeknown to most people, there is a viable alternative to concrete.
“As strong as steel but 5 times lighter”
Our answer, is wood. Specifically, constructing wooden buildings out of planks of pine laid sideways on top of each other and glued together to form a material known as ‘cross laminated timber’ (CLT).
CLT has “exceptional strength and stiffness” and is very versatile. It’s also eco-friendly, as the carbon sequestered by trees during their lives remains stored in the timber. The Physical construction also generates less CO2. As a result, CLT buildings have 22% lower global warming potential than an equivalent building made from reinforced concrete.
Wooden buildings also have to measurable physiological benefits. For example, students in wooden schools have lower heart rates and higher productivity than their concrete counterparts.
The initial reaction to wooden buildings always spring the same questions. Firstly, fire risk. Wood itself has its own anti-fire mechanism by the formation of charcoal, which is insular enough to prevent the majority of forest fires. The CLT itself is also additionally fireproof thanks to its thickness and varnish.
Trees are sustainably logged for CLT. They’re taken from specially planted forests and when one is cut down, three or four more are planted to replace it. Every seven seconds enough wood grows to make a three bedroom house in these European forests. The amount of timber needed to make a 300ft tall sky scraper currently grows every four hours.
In terms of longevity, wooden buildings can (and have) last for hundreds of years. Currently, every grade one listed building in England has a wooden roof, including churches, palaces, and parliament buildings.
The future of wood
Wooden buildings have recently started to be incorporated into green policy. For example in France, all new public buildings must be at least 50% wood or other organic materials from 2022, including the new Olympic buildings.
In the UK, over 100 educational buildings have been constructed from CLT between 2003-2011. Alongside this, over 50 buildings between 5-14 stories tall made out of timber were completed by before 2017, and the London borough of Hackney introduced a ‘timber first’ policy in 2012 in regards to buildings higher than 18 stories.
There are many different fronts the climate change battle is being fought on, and an accessible, viable solution such as this gives us one more area of positive impact.Jemma Powell Science and Technology