Timber Treading Lightly On The Landscape - The Future For Carbon Negative Building Materials
- dcb1960
- 4 days ago
- 3 min read
It was back in 2012 in its Living Planet Report when the World Wildlife Fund asserted that, if the Western developed nations continued with their pattern of consumption, we would need three planet’s worth of resources by 2050. During the years since then, consumerism and population have expanded across regions like Africa and parts of Asia, with supposedly sustainable activities such as sourcing the minerals required for electrical vehicles steadily scarring once pristine landscapes.
Meanwhile, the extra 1.1 billion people added to the population over that time not only have to be fed but also accommodated which means the need to access sufficient environmentally-friendly, and ideally carbon negative, building materials has become just as important a goal as maximising the cultivation of drought resistant plants. Undoubtedly, the UK is by no means the only country where housebuilding is failing to keep up with the crisis in demand.
MMC solutions require material advancements
The past quarter century has seen significant increases in the use of Offsite technology or Modern Methods of Construction (MMC), with engineered timber being the most popular primary material across the sector in most of Europe; with producers of competing materials also embracing sustainability goals.
Carbon negative materials are defined as those which sequester more carbon than they emit during their life cycle with other examples including hempcrete and recycled steel, aluminium or concrete. All of them, though particularly the trio of metals, constitute a precarious balance involving embodied energy, the depletion of natural resources and the time required for their replacement. Significantly, however, the formation of ores and other mineral deposits are defined by geological epochs rather decades.
As an increasingly important and costly factor, the amount of energy which goes into producing common building materials is well understood, with recycled steel requiring 74% less energy for its manufacture than the virgin product, a figure which rises to 95% for recycled aluminium which is popular for secondary structural elements like curtain walling.
Recycled steel is also now being utilised for a minor proportion of the rebar required to take the tensile forces within reinforced concrete, while recycled aggregates and waste products, like pulverised fuel ash and ground granulated blast furnace slag, are routinely specified to offset the use of energy intense cement. Ironically though, the supply of PFA and GGBS is rapidly reducing as coal-fired power plants and steel foundries are razed to the ground in the fight to counter Climate Change, making the construction industry’s quest for “ConcreteZero” ever more difficult.
The harsh reality, then, is that the heavyside construction methodologies which shaped so much of the infrastructure which surrounds us is desperately scrabbling to reach the level of sustainability which for timber can quite literally come naturally. This fact does not, of course, mean that timber-based building systems are automatically virtuous, and due diligence has to be employed to ensure that their specification will be good for the planet.
As the recent COP 30 in Brazil reminded us, forests are the lungs of the Earth, a resource we squander at our peril which is why chain of custody and whole life strategies for the use of wood are crucial. Indeed, the need for constant vigilance was highlighted last year by the organisation Earthsight when it produced the video entitled “Blood stained Birch” which exposed how since the start of the war in Ukraine, more than €1 billion of Russian plywood has been wrongly given FSC- accreditation by China and sold into Europe.
Once fully implemented, the European Union’s Deforestation Regulation (EUDR) will offer a substantial bulwark against illegal and unsustainable cropping of timber, but responsible manufacturers have already made significant strides to ensure their own operations are as well managed and transparent as possible.
With a high proportion of the company’s supplies of raw materials coming from properly-managed forests within the British Isles, and huge investment having been made in areas like production, transport and cutting waste, coupled with the use of biomass for the drying processes and a policy of only buying power from guaranteed renewable sources, the entire product range of West Fraser in the UK has now achieved Carbon Negative status.
This ensures its own customer network can be assured that the panel products they are using to produce structural insulated panels (SIPs) and other offsite systems like floor cassettes, as well as for sheathing, decking and other applications, all fully meet the spirit as well as the regulations which will expand the use of carbon negative building materials.
