GROWING OUR LOW-CARBON FUTURE: TIME FOR TIMBER
The construction and built environment sector is responsible for approximately 40% of global energy related CO2 emissions.[i] A significant percentage of which comes from the extraction, processing and energy-intensive manufacturing of building products.
To achieve net zero CO2 emissions by 2050, construction must rapidly decarbonise whilst still meeting the needs of a growing urban population, the increasing demand for new buildings and the urgent requirement to renovate existing buildings.
Wood is the only sustainable structural material that grows worldwide which can enable a substantial decarbonisation of the built environment based on existing business models and proven technology; providing vast carbon sinks in our rural areas and carbon stores in our cities.[ii]
The climate case for wood
The built environment is responsible for approximately 40% of global carbon emissions. This comes from two main sources:
- The energy we consume within buildings for heating, cooling and lighting (operational emissions)
- The emissions associated with the extraction, processing and manufacture of building products (embodied emissions)
Wood is a naturally renewable material which:
- Sequesters carbon in forests as trees grow
- Stores carbon in harvested wood products
- Substitutes for carbon intensive materials such as steel, concrete and plastics
- Drives Sustainable forest management leading to greater growth
- Contributes to a Circular economy as wood products can be reused, recycled and recovered for low-carbon energy at end-of-life
Increasing the use of wood is an effective way to reduce both.
Timber has naturally insulating properties, as it is 10 times more thermally efficient than concrete and 400 times more than steel, reducing operational emissions created due to heat loss within buildings.[iii] This makes timber and timber products ideal for the renovation and improvement of energy performance in existing buildings.
Lifecycle Assessment studies consistently show that timber products absorb and store more carbon than is emitted through their production – making them a net carbon reducer.
Using more wood in the built environment, including in furniture and interiors, is a natural, cost-effective, and sustainable carbon-capture solution, [iv] as once managed forests are harvested, more trees are planted, and more carbon is sequestered.[v] Increased investment into sustainable timber also provides viable income for local communities, creating incentives for sustainable forest management, preventing deforestation and encouraging conservation of biodiversity and ecosystem services.[vi]
In addition, using wood products in construction displaces the use of carbon intensive alternatives such as steel, concrete and plastics, thus reducing emissions even further.
Timber; the urban solution
Timber buildings have already been built that are more than 18-storeys in height, thanks to the development of new, innovative, engineered wood products – and will reach even greater heights this century.
Contemporary urban areas now enjoy buildings using wood at height and at scale. Products such as Cross Laminated Timber (CLT), Glued Laminated Timber (Glulam) and Laminated Veneered Lumber (LVL), have the structural strength of steel and concrete with the added advantages of being light in weight, thus not requiring such substantial foundations or significant transport to move.
Timber and timber frame buildings can be prefabricated in offsite factories, requiring fewer deliveries to site, having quicker on-site assembly times, with far less dust and noise to disturb other local residents.
Wood offers modular possibilities to redesign and modernise buildings via additional storeys, roof extensions and interior refurbishment, maximising the lifespan of existing buildings and reducing the need for demolition. Recovered wood also has the potential for reuse to manufacture new products, extending the time the carbon is stored.
Despite some mistaken perceptions and rhetoric, finished timber buildings have no greater fire risk than concrete and steel buildings.
Europe’s forest areas has increased by 10% over the last 30 years, at a rate of 643 thousand hectares per year.[vii]
Likewise, in the United States and Canada, sustainable forest management has resulted in more than 50 consecutive years where growth has exceeded harvest.[viii]
This growth has been encouraged by the commercial management of forests for timber and other forest products.
We are calling on political leaders and policy makers in every country to recognise forests and the global wood and forest industries as a major solution toward a more climate-resilient economy. This can be achieved through the following policies:
- Embed mandatory lifecycle assessments and embodied carbon thresholds within local and national building plans. Only be measuring our environmental impacts will we be able to manage and steadily reduce our impact. These should be measured according to common metrics using existing tools, such as Environmental Product Declarations (EPD).
- Increase the use of wood within new build and renovation. There is a need for affordable homes all over the world. Up-scaling must be done in a cost and climate effective way, using off-site, industrial prefabrication based on light, high quality, easy to transport, and sustainable, wood-based solutions. This will allow for less disturbance next to construction sites, reduced waste and increased affordability.
- Drive the growth of the bio-based circular economy through sustainable public procurement. Harnessing government spending to advantage climate-friendly solutions for construction and renovation of the building stock will allow investment and rapid expansion of the sector, thus supporting societal climate reduction goals.
- Facilitate resource efficient use of wood and wood recycling, especially collection and sorting in municipalities, and develop measures to gain access to post-consumer wood, an invaluable secondary raw material resource. The recovery and reuse of wood helps to prolong carbon storage and maintain availability of resources for further life cycles. Using the same wood multiple times is the most efficient use of this natural, sustainable and precious resource.
- Increase training to upskill workers and create new jobs to boost the development of a sustainable and circular bioeconomy. New areas such as modern renovation and prefabrication require different skillsets and knowledge bases. Enhancing training and education is essential to a) create more sustainable, green jobs, b) develop the new skills in nature-based materials and c) improve the traditional manufacturing in wood industries.
In conclusion, wood must be adopted more widely in the global built environment. The potential climate impacts of using more wood and wood-based materials are immense: they offer solutions based on existing business models and proven technology which simultaneously store carbon and substitute fossil resources, and thus can diminish the CO2 emissions caused by the global building stock.
Growing our low-carbon future: Time for Timber
This document was produced by:
[i] Global Alliance for Buildings and Construction. 2020, Global Status Report For Buildings And Construction, 4.
[ii] Churkina, G., Organschi, A., Reyer, C.P.O. et al. Buildings as a global carbon sink. Nat Sustain 3, 269–276 (2020). https://doi.org/10.1038/s41893-019-0462-4
[iii] Zhen, M.; Zhang, B. Energy Performance of a Light Wood-Timber Structured House in the Severely Cold Region of China. Sustainability 2018, 10, 1501. https://doi.org/10.3390/su10051501.
[iv] Royal Society and Royal Academy of Engineering. 2018, Greenhouse Gas Removal, 46
[v] Intergovernmental Panel on Climate Change. 2019, Summary for policy makers, In: Climate Change and Land, 21.
[vi] Dean, C.. 100% Sustainable Timber Markets: The Economic and Business Case, 2016, WWF.
[vii] EuroStat, Forests, forestry and logging. (Last accessed 8 October 2021).
[viii] Woodworks. 2013. Sustainability Forestry in North America, 5.