Every home not being built with wood misses an opportunity to lock up carbon.
Construction must do better globally to help reach sustainability targets and decrease harmful carbon emissions. One step towards greener buildings is using wood.
So, how is the rest of the world using wood in construction? Outside of England, many countries are making the most of wood’s environmental credentials, building new homes and even skyscrapers from the natural, renewable building material.
The UK catapulted timber into the tall building arena more than a decade ago with Waugh Thistleton’s 29m tall cross-laminated timber (CLT) apartment block, Stadthaus, in Hackney. Hackney became the motherland of CLT structures when Hackney Council adopted a ‘wood first’ policy, and Stadthaus was joined by Hawkin/Brown’s The Cube and the colourful WoodBlock House by dRMM.
Timber engineering has allowed wood to be used in construction as never seen before, particularly in cities where building up is often the only option. But in 2018, the UK’s tall timber building potential was stymied as wood was banned from use in buildings over 18m.
The tall timber building trend has continued, however, and around the world, via varying building regulations, building the world’s tallest timber skyscraper has become a competition of innovation.
Norway currently holds the accolade for the world’s tallest timber building. Mjøstårnet is a mixed-use tower, designed by Voll Arkitekter and constructed by Hent and Moelven Limtre. It stands at 85.4 metres and is created from a glue-laminated timber (glulam) structure with CLT walls for secondary loadbearing.
Currently under construction is the HAUT building in Amsterdam. At 73m it will be the tallest wooden residential building in the Netherlands. The building is being created from CLT, with the foundations, basement and core made from concrete. To further the building’s sustainability credentials, triple glazing, recyclable materials and an energy-generating façade are also being added.
Ambitious plans for new buildings created from timber are also cropping up in Australia, Germany, Canada, Japan, New Zealand, the US and more.
Many of the countries showcasing the best of what timber can offer benefit from supporting government policies and building regulations. In the US, the International Code Council (ICC) adapted 14 of its codes to allow mass timber to be used up to approx. 55m.
Canada published its ‘State of Mass Timber’ report as part of its Green Construction Through Wood programme. The report claims Canada is the world leader in building with wood and references more than 400 projects. It includes the University of British Columbia’s Brock Commons Tallwood House, claimed to be the world’s highest mass CLT building, which reports its carbon emissions mitigation equivalent to removing 500 cars from the road each year, a saving of 2.4t of CO2.
The Canadians are also using timber for bridges and agricultural buildings and they are excited for what the future brings as they make revisions to the National Building Code of Canada to allow mass timber in buildings up to 42m.
From April this year, Denmark allowed timber to be used on buildings up to 45m.
But timber isn’t exclusively used for tall buildings. In Australia, lightweight framing is the most common way to build, with timber or steel being the preferred materials. The environmental benefit of using timber is not lost and a comparison between sawn timber, steel, concrete and aluminium shows that timber not only releases the least carbon during construction, but it is also the only building material that stores carbon.
In New Zealand, timber frame is the dominant system used to construct houses, with a historical market share of around 90% compared to steel framing, masonry or concrete, for example.
Taking timber use a step further, the French government announced last year that all new public buildings must be made from at least 50% timber or other natural materials, with implementation taking place from 2022.
Building with timber is commonly reported in the aforementioned countries, but its environmental and innovative benefits are being recognised even in the smallest countries.
The Republic of Artsakh Government began a timber-framed home pilot programme at the start of the year and Timor-Leste, which currently has no building regulations for building greener is looking to use coconut timber and bamboo among other natural materials. The tiny island is number nine on the list of countries most vulnerable to climate change with approximately 400 homes lost to disaster each year.
While the global appetite for timber in construction is growing, it’s important to consider the factors that are preventing growth
Following the tragic Grenfell Tower fire in 2017 and Dame Judith Hackitt’s consequent inquiry, the UK’s blanket ban on using combustible materials above 18m has diverted attention to fire safety. Safety is paramount for any building and while timber is an obvious sustainable choice for greener buildings, proving fire resistance is key for furthering its use.
Elsewhere, the fire safety evidence appears to be satisfactory for the governments pushing their timber building agenda forward. There’s much the UK can learn from this and supporting government policies and building regulations are fundamental if we are to meet sustainability targets.
Timber supply, and its current shortage, presents a challenge for many countries, especially those reliant on it being sourced externally. In the UK there is a shortage, but the timber industry needs to continue stoking up the demand and capitalise on the importance of using timber in construction. It proves the need for more homegrown timber and investment from the government to support UK forestry.
Another key consideration, particularly for countries supplying tropical timber is sustainable procurement. In Latin American, African, and Southeast Asian countries, deforestation and piracy is a major issue with illegal logging damaging the environment, local economy and removing opportunities for local people. Compliance schemes and certification systems, such as PEFC, ensure the supply chain is regulated to prevent illegal timber from entering global timber markets.
The future for timber is bright. Though it feels stalled in the UK, the rest of the world is grabbing this natural, renewable building material and applying it where possible to create a greener built environment. The UK timber industry and all who champion building with wood are tasked with the vital challenge of providing the evidence needed that allows the UK to re-join the race for greener buildings with supportive robust and progressive legislation.