Protecting forests from changes in land use, increasing planted forests, improving sustainable forest management and using certified wood to build high-rise buildings can help meet the challenge of cutting down carbon emissions and tackling climate change. To foster a greener building sector would also contribute to a bio-based, more sustainable economy.
Just in Europe, according to the European Forest Institute, the forest-based sector “provides more jobs than the steel, chemicals and cement industry together”, and engages 16 million forest owners.
Architects and companies are betting on wooden skyscrapers around the world. For example, Alphabet, Google’s parent company, is investing 900 million dollars (approximately 830,3 million euros) in a high-tech neighbourhood for its subsidiary Sidewalk Labs. It will be built with mass timber along the waterfront in Toronto, Canada.
According to a study carried out by scientists from Yale School of Forestry & Environmental Studies and the University of Washington’s College of the Environment, “Building with wood consumes much less energy than using concrete or steel. For example, a wooden floor beam requires 80 megajoules (mj) of energy per square metre of floor space and emits 4kg CO2. By comparison, a square metre of floor space supported by a steel beam requires 516 mj and emits 40 kg of CO2, and a concrete slab floor requires 290 mj and emits 27kg of CO2.”
Another research quoted by the architecture website Archdaily.com states that “the life-cycle emissions of wood houses are 74% lower than those of steel houses and 69% lower than those of concrete houses”.
Wood is no stranger to the construction sector, although until very recently its use was limited to buildings not taller than two or three stories. Now wooden high-rise buildings are popping up in different cities around the world.
Apart from timber’s intrinsic strength, stability and flexibility, a series of new technologies allow it to further increase its performance and is resistance to fire. Cross-Laminated Timber (CLT), for example, is a large-scale, prefabricated, solid engineered wood panel, while Glued Laminated Timber (GLT), or glulam, is a highly innovative construction material, stronger than steel and has greater strength and stiffness than comparably sized dimensional lumber.
These engineered woods are key for building high-rise wooden buildings. CLT and GLT are being used more and more often in construction because they allow architects to design fire-resistant high structures.
It is time for timber. The environmental benefits associated to building with wood are undoubtable. It takes CO2 out of the atmosphere and stores it both in forests and in the structures of wooden buildings in cities, as carbon dioxide stays stored it in wood, even when it is transformed into a wood-based product. Using wood as building material will also support rural economies and provide more sustainable, energy-efficient, affordable housing.