Can Forest Waste Help Solve the Structural Timber Crisis?

Studio Bark devises structural use for waste timber in English woodlands

Mon 29 Jan 24


Could timber waste and offcuts unsuited for traditional sawmilling be salvaged from overgrown and undermanaged forests and used for high-value timber products, like structural roof columns?

That is the question posed by London-based architects Studio Bark, a practice that strongly focuses on socially conscious projects, including a low-impact demountable timber house in rural England and a self-build modular construction system that Extinction Rebellion has used as “protest architecture.”

Now, the practice has been working with the University of East London researchers on a project called “Spindles”, upcycling timber and using it in low-carbon housing with potential applications across the UK.

In effect, the project looks at converting reclaimed timbers destined for firewood into structural building projects whilst also stressing the importance of removing overgrown wood that, according to forest experts, is critical to rehabilitating the natural environment.

It comes as Portuguese scientists last year discovered that forest waste and fungi, often left after harvest, can be turned into high-value products and engineered into a substitute for interior wall cladding.

The breakthrough not only helps the construction industry face the global shortage of timber but also decarbonises buildings and creates circular value-added products to meet future demand.

According to Ella Thorns, a Studio Bark architect, the discovery came after it was engaged to build a new family home on a wooded site in Buckinghamshire – in England’s South East. 

Ms Thorns said just 9% of English houses use timber frames, and despite a concerted effort from the UK government, more needs to be done, “not least a lack of forest cover.

Trees play an important role in managing the world’s ecosystems; however, according to researchers, selective debris and tree removal play an all-important role in restoring forest health and improving the forest’s carbon performance – footage courtesy of @eons.

On the property, she said the design team “immediately realised that the woodland was in bad condition to someone who knows what that looks like – which I didn’t at first, but you can tell very quickly from looking at the floor of a forest, and there was just no growth happening at all.” Before adding that “it was very dead.”

“We were there in midsummer. You should have this flourishing understory of shrubs and plants, and there was just nothing and many of the trees are very tall and spindly,” Ms Thorns told Dezeen.

That’s when Studio Bark engaged Evolving Forests, an expert “in tree growing and timber use”, to develop a “woodland management strategy” to restore the woodland’s forest health.

That posed the question of what to do with the felled trees…

The studio wanted to use them, but these were not the sorts of trees ordinarily accepted by sawmills and turned into construction timber – they were too small and irregularly shaped.

“In the UK, we don’t have anywhere near enough timber that we need for current demand,” Ms Thorns stressed. “So we then questioned, can we use this timber, which is not the sort of stuff you buy on the shelf.”

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Cutting the wood in round lengths allowed smaller pieces to be used without losing structural strength.

Usually, “rejected” timbers are sold for firewood or left to decay, but that would release the carbon dioxide the tree had sequestered in its life, and Studio Bark wanted to avoid that outcome.

They also found inspiration in the area’s cultural heritage.

According to Ms Thorns, Buckinghamshire is the historic centre of production for the Windsor chair, and the spindles of its backrest represent a very efficient way of using small pieces of wood.

This is because you can use a smaller piece of timber if you cut a circular cross-section rather than a square one of the same area and strength. It is “an old technique”, said Ms Thorns, but one that opens up many opportunities to use smaller trees.

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Only the strong inner heartwood can be used for construction.

The round wood lengths complement the tree’s natural growth pattern, where the rings grow around any defects, resulting in less wastage. 

The spindle shape — fatter in the middle, thinner in the ends — is also valuable, opening up opportunities for greater utilisation of the timber.

“If you were to draw a force diagram, you’d need more material in the middle, so naturally, it’s a win-win,” she said.

When it comes to the triple bottom line, it’s a win-win-win…

Working with acclaimed tree surgeon Ben Harris and researchers from the University of East London’s School of Architecture, Mr Harris cut the wood on-site using an electric lathe.

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Researchers from the University of East London School of Architecture are working with Tree Surgeon Ben Harris in the Buckinghamshire woodland. (Photo Credit: Studio Bark).

They then worked with the structural engineer Structure Workshop to develop a plan for using the small wood sections in an architectural context, envisioning them as pieces of a larger column. 

They also built a 1:3 structural model of a possible spindle application, consisting of columns of wood connected by a glulam beam, with spindles emerging from the beam to support a roof.

According to Ms Thorns, the impact of the Spindles project was “wider than the actual design” and more about a “methodology of thinking” around timber that considered “not just the carbon metric but also the biodiversity and social metric”.

“We need to look to alternative sources and design buildings that make timber go much further,” she said. “The Spindles project does just this, increasing the conversion rate of the tree to useable timber and working with homegrown timber that is usually overlooked.”

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Studio Bark took inspiration from local carpentry to develop its project. (Photo Credit: Studio Bark).
Inside UK’s Bold Timber Roadmap Driving Net Zero Construction!

In December, Wood Central revealed that the UK has revealed plans to scale up timber used in construction, which the government acknowledges “is (one of) the best way to reduce emissions in buildings” and meet Net Zero targets.

Known as the “Timber in construction roadmap”, it is the most ambitious policy delivered by Rishi Sunak’s Conservative Government to reduce the barriers to using timber construction across England.

It will promote English forestry as a “green investment opportunity,” market homegrown C16 softwood timbers “as a fit for purpose” solution and develop higher-strength timbers from its forest resource.

According to Forestry Minister Rebecca Pow, the policy supports the Sunak government’s investment in growth before adding, “the built environment is responsible for a huge proportion of UK carbon emissions, (with) homegrown timber key to reducing emissions.”

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Last year, Wood Central reported that the UK’s Net Zero commitment was at risk after missing key tree planting targets. (Photo Credit: Ashley Cooper via Alamy Stock Photo).

Whilst just 9% of English homes are timber-framed, more than 92% of Scottish dwellings are constructed from timber. 

“By expanding low-carbon timber construction, particularly in the housing sector, we can decarbonise our built environment whilst simultaneously building high quality, efficient buildings,” according to David Hopkins, the CEO of Timber Development UK.

With exemplary projects like Spindles, perhaps the UK building and construction industry can embrace sustainably managed timbers as the construction material of the next century.


  • Wood Central

    Wood Central is Australia’s first and only dedicated platform covering wood-based media across all digital platforms. Our vision is to develop an integrated platform for media, events, education, and products that connect, inform, and inspire the people and organisations who work in and promote forestry, timber, and fibre.


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