4 Common Myths About UK-Grown Cross Laminated Timber (CLT)

Cross Laminated Timber (CLT) is a sustainable, high-performance construction material with the potential to improve speed and quality of builds. However, misconceptions persist within the industry, especially around CLT and other mass timber products made from timber grown in the UK due to historic perceptions.

Building on the findings of the Innovate UK research project Transforming Timber, the Mass Timber Centre of Excellence provides dedicated support to help the construction industry overcome these barriers and misconceptions. The Centre enables the sector to realise the full potential and benefits of UK mass timber construction by facilitating the successful integration of UK-grown timber into projects nationwide. This article addresses four prevalent myths and presents the evidence-based reality.

Myth 1: Homegrown Timber Lacks the Structural Strength of European Timber

The Reality: All structural timber used in UK construction must meet stringent strength grading requirements and comply with relevant engineering specifications, regardless of origin.

A widespread misconception suggests that Scottish-grown mass timber cannot match the structural performance of European alternatives, particularly for CLT applications. Research from Edinburgh Napier University has definitively disproved this assumption.

The study demonstrates that Scottish-grown timber graded to C16 exhibits enhanced properties compared to imported alternatives. Key findings include superior bending strength and greater timber density, both critical factors in CLT manufacturing and structural performance.

These findings led to the establishment of the strength class C16+, specifically developed to recognise the enhanced properties of UK-grown timber. This classification enables designers to specify CLT structures with improved performance characteristics and greater material efficiency, providing significant advantages for real-world construction applications.

Myth 2: Using Homegrown Timber for CLT Is Unsustainable Due to Deforestation

The Reality: Responsibly managed forests deliver substantial environmental benefits, including carbon sequestration, habitat preservation, and biodiversity enhancement. Utilising timber from these forests for construction does not contribute to deforestation.

Wood used in CLT and other construction applications possesses a unique capacity to sequester carbon long-term. When timber remains in a building or engineered wood product, it continues to store the carbon absorbed during tree growth, effectively removing it from the atmospheric carbon cycle and mitigating climate change impacts.

Sustainable forest management is essential to maintaining this environmental benefit. Harvesting timber for construction purposes necessitates planting replacement trees, which actively sequester carbon as they grow. This cycle ensures forests remain productive carbon sinks.

Myth 3: Scottish Timber Is Only Suitable for Low-Value Applications

The Reality: This misconception stems from outdated perceptions regarding Scottish timber quality.

Over the past decade, extensive research and industry collaboration have demonstrated that UK-grown timber is highly suitable for engineered timber products such as mass timber, including CLT panels and beams. These advanced applications represent some of the highest-value uses for timber in modern construction.

CLT manufactured from UK timber has been successfully specified across diverse project types, from residential developments to commercial buildings and educational facilities.

A significant portion of this work has been delivered through the Transforming Timber project, a collaborative knowledge hub promoting the use of homegrown mass timber. The project has delivered some UK-first innovations, including the UK’s first two-storey homegrown mass timber house and the GenZero school prototype for the UK Government Department for Education (DfE). All these projects used UK-grown, load-bearing mass timber panels and beams in their structures.

The material's proven performance in demanding structural applications has established UK-grown CLT as a viable alternative to imported engineered timber products.

Myth 4: UK-Grown Timber Is More Expensive Than Other Construction Materials

The Reality: It is commonly thought that building with timber is more expensive than other construction materials such as brick and block. However, this is a misconception.

Numerous factors influence the cost of a construction project, including project size, design complexities, labour requirements, and site-specific constraints. However, market reports from 2022 indicated that timber manufacturing costs were 65% of the average cost of a typical brick and block-built home.

Beyond material costs, CLT construction offers substantial cost savings through reduced build times. The prefabricated nature of CLT panels enables faster on-site assembly compared to traditional construction methods, reducing labour costs, site overheads, and project financing expenses. The lightweight properties of CLT also reduce foundation requirements, delivering further cost savings on substructure works.

In terms of cost advantages of homegrown mass timber compared to imports every piece of timber used within the site to manufacture the mass timber is graded at C16. However, European imports will be C24, which is potentially overengineered and therefore the likelihood is the client will be overpaying for a product.

Homegrown C16 graded timber is currently £50m³ cheaper than imported C24.

It is important to know that construction material costs regularly fluctuate. To keep up to date with changes in timber costs, Timber Development UK publishes monthly economic statistics on timber here.

Why choose Homegrown CLT and Mass Timber for construction

Using UK-grown CLT, Glulam and mass timber brings compelling advantages such as speed, strength and sustainability. Understanding the evidence behind common misconceptions helps construction professionals make informed decisions about specifying homegrown CLT. 

For construction project teams and clients, the mass timber specialist team at BE-ST can support the specification of mass timber for construction projects, to become a viable option that supports both project objectives and sustainability goals.

The Mass Timber Centre of Excellence provides support for the industry to integrate timber into projects, with access to the UK’s largest mass timber manufacturing facility, for organisations to design and build quicker, higher quality, and more effectively using this sustainable material.

If you are interested in using UK-grown cross laminated timber or mass timber, get in touch here for a discovery conversation with a member of our team.