Reuse

The longer you keep timber in the built environment, the longer you can store carbon. This makes reusing timber elements, along with concepts like cascading material use and designing for deconstruction, crucial to our net zero transition.

While reusing timber elements is not without its challenges, it is crucial to helping support a low-carbon transition for our built environment. If the UK construction sector can treat timber not just as a one-time carbon sink, but as a long-term carbon asset, it will strengthen both our circular economy and net zero transition. This page explores the pathways to greater reuse.

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Explained

01 Why reuse timber elements

Timber Circular Design: Waste Wood. Explore how timber is currently being used at end of life, and how we can make it more circular.

As the UK transitions toward a net-zero economy, attention in the construction sector is shifting from simply using low-carbon materials, to ensuring that carbon remains stored in the built environment for as long as possible. One key strategy to achieve this is the reuse of timber, especially through cascading uses that extend its life across different applications, and through designing for future disassembly and reuse.

Timber naturally stores carbon absorbed during a tree’s growth. When used in buildings, this carbon remains locked away, often for decades. However, when buildings reach end-of-life or undergo refurbishment, the carbon value of that timber can either be preserved - or lost. Reusing timber elements, either in part, or in whole, can help ensure that the carbon will remain locked away for as long as possible.

This practice contributes directly to circular economy goals, reducing reliance on new timber and avoiding the majority of emissions associated with harvesting, processing, and transport. Some studies have shown that reclaimed wood can have a significantly lower carbon footprint than both virgin timber and conventional alternatives like concrete or steel.

Placing greater emphasis on reuse – by keeping a construction product in its original form for as long as possible, or when no longer appropriate, transforming this timber product for another built environment use – also helps support timber security, and can help ease pressure on forests to keep up with demand. Achieving this balance will be important, particularly with demand for forest products projected to continue to grow.

02 Reuse of whole timber elements and designing for deconstruction (DfD)

The assessment of the mechanical and physical properties of in situ timber. This paper looks at the current state of testing.

In a traditional demolition, glued and fixed materials are typically damaged making the full recovery of timber elements difficult. However, with design for deconstruction (DfD) principles - such as using mechanical fixings, modular grids, and accessible connections – timber elements such as CLT panels or glulam beams can be removed intact and reinstalled elsewhere.

Reused mass timber elements can retain their structural integrity, provided their history is traceable and condition verifiable. While the development of digital material passports and building information modelling (BIM) systems in the UK support better tracking of the provenance, grade, and prior use of timber elements, ensuring structural performance still needs to be assured.

Wood reclaimed from old buildings may have hidden defects, such as internal rot, insect damage, or embedded fasteners, making inspection and grading essential - particularly if it will be reused for a structural element of a building. Engineers must verify whether reclaimed wood meets performance standards for load-bearing uses, particularly in modern structures with stricter codes.

Standards like EN 14081 provide frameworks for evaluating reclaimed wood, while Universities and private institutions, both in the UK and globally, have been focused on solving this issue – some of which is reflected in the TDUK research summaries on ‘The assessment of the mechanical and physical properties of in situ timber’, and the 'InFutuReWood: use and reuse of wood building components'.

03 Cascading timber elements for different uses

When structural reuse in its original form is no longer viable, timber elements can still be repurposed into a range of structural or non-structural products that help keep the material - and its embodied carbon - within the built environment. These reuse pathways are supported by well-established supply chains and include applications such as chipboard for flooring, furniture and interior finishes, and wood fibre insulation.

Only when timber can no longer serve any functional role in the built environment should it be directed to biomass energy recovery. This step should be delayed as long as possible by recycling timber products to ensure maximum carbon retention within products. However, when eventually used as fuel, timber can provide a lower-carbon energy source for industrial processes compared to fossil alternatives.

This cascading use strategy extends the material’s service life across multiple product cycles, helping to maximise carbon storage, minimise demand for virgin materials, and enhance the resilience of the UK’s timber supply. As such, it plays a crucial role in advancing both circular economy principles and a low-carbon built environment.

The only exception to this reuse hierarchy occurs when timber has been treated with products such as creosote or contaminated to the extent that it poses a hazard. In these cases, appropriate controlled disposal routes must be followed, usually via high temperature incineration.

Importantly, less than 1% of timber in the UK ends up in landfill, usually due to the lack of segregation during disposal.