As we learned from Nick Milestone’s podcast episode, using timber in construction reduces its carbon footprint. Personally, the thought of having more wood in our houses and buildings is very appealing. I know it is not just me, as Biophilia, our connection to nature, is a known phenomenon.
The advantages of using timber
Numerous advantages of using timber are outlined in Nick’s conversation and include:
- Timber is a sustainable material because you can cut a tree down and grow another.
- Carbon is sequestered (posh term for absorbed/taken in) by growing trees and locked in the timber construction.
- Timber reduces concrete use, which is horribly energy-intensive with a high carbon footprint, enabling net zero buildings.
- Timber buildings are robust and should still be standing in a few hundred years.
- When buildings are dissembled, the timber can be reused or burnt for energy generation (the carbon dioxide released here can be mitigated by further tree planting).
Timber is clearly an excellent resource for the construction industry, but a sustainable supply is crucial.
Global forests
I can be a bit nerdy, so here are some facts and figures, to give a bit of context. According to the FAO (Global Forest Resources Assessment, 2020), global forests amount to about 4 billion hectares (ha) and cover 31% of the land area. The top 5 countries having the most forested areas are the Russian Federation, Brazil, Canada, the United States of America and China. Of the global forests, 93% (3.75 billion ha) is composed of naturally regenerating forests, and 7% (290 million ha) is planted. The planted forests are either intensively managed for production or planted for ecosystem restoration. A high proportion of naturally regenerated forests are also actively managed. More than 2 billion ha of forest have management plans, 1.15 billion primarily for wood and non-wood products.
What does a sustainable forest look like?
What it does not look like is whole forest logging and destroying the valuable ecosystems within them. A sustainably managed forest fulfils ecological, economic and social functions. The point here for timber production is to enable ongoing logging without the detriment to the overall health of the forest and those that enjoy it. Management practices vary. Intensively managed forests will often consist of one or two species of similar ages and planted with regular spacing. However, other management practices are available, such as continuous cover forestry, encouraging greater diversity.
In the UK, the Woodland Trust aims to mimic how nature deals with disturbance and regeneration, balancing the competing needs of timber building materials and biodiversity. Selective tree removal can benefit wildlife and biodiversity by creating gaps in the canopy; replanting suitable trees replenish the forest to provide a continuous supply.
Certification of sustainability
Suppliers of timber can demonstrate sustainability through certification programmes, of which there are many. For example, the woods managed by the Woodland Trust are certified by the UK Woodland Assurance Standard (UKWAS) and the Forest Stewardship Council (FSC). The UKWAS certification depends on meeting requirements for pesticide use and genetically modified organisms. Environmental impact assessments are required, native species are preferred, and felling restrictions are applied on the area within semi-natural woodlands over five years.
The Forest Stewardship Council (FSC) is a global forest certification system with two key components: forest management and the chain of custody. The latter ensures that all organisations involved in the supply chain, from forest to product, are checked before ascribing the FSCs label to the end product. Audits are carried out by independent FSC accredited certificating bodies.
Another commonly used global system is the Programme for the Endorsement of Forest Certification (PEFC). Requirements can vary from nation to nation, as forests are diverse, reflecting the differences in local environments. However, there are sustainable forest management requirements that have to be met by all forests. These include: maintaining, conserving and enhancing ecosystem biodiversity, ensuring ecological forests of high importance are protected, prohibiting genetically modified trees and most hazardous chemicals, prohibiting forest conversion (deforesting to use the land for other purposes), and climate positive practices.
I was aware of the FSC/PEFC logos on items, but now they seem to spring up into my consciousness and I am now more likely to question those with no identifying sustainability mark.
Getting the right balance
All in all, as with many environmental conundrums it seems, the solution is about balance. Timber is a great resource, leading to a reduced carbon footprint within the construction industry and provides beautiful places to live and work. Using sustainably managed timber ensures the protection of our natural world, which is so essential for our wellbeing.