Timber: The sensible and sustainable choice
Timber is the only construction material whose volume is increasing all the time with the material needed for a medium-size wooden high-rise growing in Finnish forests in 30 seconds. Metsä Group outline why timber should be a serious proposition for all construction professionals.
The carbon footprint of a timber building is small. Throughout its lifecycle, it causes considerably less climate and environmental burden than buildings made from concrete, brick or steel. Wood is an environmentally friendly and strong natural product that can be converted into diverse products that function as carbon storage. “Wood is applicable to almost anything that can replace fossil-based and other raw materials harmful for the environment in construction,” says Matti Mikkola, Managing Director of the Federation of the Finnish Woodworking Industries.
Wood will not run out due to construction – this means that we are not about to run out of timber due to construction – as long as the timber comes from an area where forest management and use are as professional and responsible as in northern Europe.
Only 10% of the world’s forests are certified, but nearly 90% of the wood used by Metsä Group is certified. This certification is a guarantee of responsibility and an indication of the sustainable management and use of forests. The wood that Metsä Group uses comes from the densely forested areas in the north, where forests grow more than they are used and where the carbon storage of forests continues to expand.
Metsä Group’s sustainability aims include increasing the amount of carbon stored in forests to a significant degree. They also aim to increase the amount of carbon stored in their products by 30% by 2030. This is done by increasing the production of products which store carbon for a long time, such as sawn timber and engineered wood.
The amount of carbon stored in forests is increased by providing more forest management services that speed up growth and by encouraging forest owners to manage their forests responsibly.
Metsä Group delivers 30million seedlings to forest owners every year, and every tree harvested in a regeneration felling is replaced with four new seedlings. The company has also carried out a vast amount of research and development work which allows them to provide the seedling with the best possible growth conditions after they are planted in the ground to replace a harvested tree and accumulate new carbon storage.
A wood product is a climate act – timber has the unique ability to absorb carbon dioxide from the atmosphere and store it. To grow, one kilogram of wood needs approximately 1.55 kilograms of carbon dioxide, and the carbon from this is stored in the wood. The rule of the thumb is that one cubic metre of wood stores a tonne of carbon dioxide.
“Being renewable and recyclable, wood is the best construction material from a climate perspective, because it stores carbon within it,” says Mikko Saavalainen, Senior Vice President, Business Development at Metsä Wood.
Wood’s ability to store carbon will therefore not disappear when a tree is felled. Processed wood will function as a carbon store for as long as the product made from the wood exists. “A building constructed of wood will function as carbon storage throughout its lifecycle,” adds Saavalainen.
An average Finnish single-family house built from wood stores roughly 30 tonnes of atmospheric carbon dioxide within its wooden structures. This is equal to the carbon dioxide emissions generated by the average mileage driven by one consumer over a period of 10 years.
Wood provides better urban construction – the benefits of wood construction including the lightness of the material, fast construction and environmental friendliness – provide innovative and sustainable opportunities for modern construction, particularly in growing urban environments, where the need for housing is increasing.
At the moment, timber accounts for approximately 5% of construction in Europe. “The use of wood should be increased particularly in cities, because wood construction can reduce the carbon footprint of urban environments to a substantial degree,” says Saavalainen.
“If the share of wood in urban construction increased,” adds Mikko Saavalainen. “It would have an enormous climate impact – and there would still be no need at all to compromise on the quality of construction. The same structures that are made from concrete or steel could just as well be made more ecologically from renewable and sustainably grown wood.”
The right material to the right place – however not everything should be built from wood. Rather, the wisest solution in terms of resources is the selection of the right material for the right place. “Nowadays, concrete is the best material for foundations, and glass works in windows, but when designing a concrete building, we should also consider whether certain structures can be made from wood, which is lighter and stores carbon,” says Jussi Björman, Director, Technical Customer Service, Metsä Wood.
One square metre of wall built from timber creates a carbon stock of roughly 50 kilograms. If a timber wall replaces an equivalent concrete wall, the 110-kilogram carbon dioxide emission attributable to the production of the concrete wall can be avoided. In other words, wood binds the carbon dioxide in the air, while other materials produce it. Every wooden element in a building is a step towards something better for the climate.
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