1st May 2024

Timber engineering for a sustainable future: the challenges, opportunities and joy


Our managing director and co-founder Julian Broster recently presented at the Structural Timber Conference 2024, in partnership with the Structural Timber Association. The conference showcased the latest case studies, trends and technologies in structural timber, chaired by Andrew Carpenter, CEO of the Structural Timber Association.

Here, Julian explores the critical role timber engineering has to play in the transition to Net Zero:

The route map for UK Net Zero 2050 is clear, as is the scale of the challenge as the country pursues a just-transition over the coming decades. Some UK core cities have set shorter timescales for their own Net Zero Carbon transition periods, such as Manchester by 2038. Alongside de-carbonisation of the concrete and steel industries, timber construction has a major role to play in this transition, not least of which being the forecast that the market share for timber frame construction for new UK housing is set to increase from just under 25% to 40% by 2030.

As it stands, the UK built environment is responsible for approximately a quarter of UK greenhouse gas emissions, 11% of which is attributable to the mass manufacture of post-industrial building materials.

It is clear that emissions from the built environment must be drastically reduced if the UK is to meet Net Zero by 2050. The Environmental Audit Committee (EAC) has highlighted the lack of central government impetus to address the issue and called for urgent action to incorporate mandatory requirements for whole-life carbon (WLC) assessments. These WLC assessments specifically include upfront and lifecycle embodied carbon, as well as operational carbon, for inclusion into both the town planning policy as well as the Building Regulations. The slow progress of the Carbon Emissions Bill through the House of Commons since its first reading in 2022 is evidence of this inertia. However, influential policy lobbying initiatives such as Part Z, which has widespread support from across the built environment, provides optimism of industry-led progress.

The future regulation of Whole Life Carbon Assessment will inevitably, and quite rightly, support the increased use of structural timber in UK construction. Given the severity of the climate emergency and push for further action, we must continue to collectively develop our skills as an industry. Developers, government agencies, designers, suppliers and constructors must collaborate and positively contribute to redefining the future of timber construction.

Building in sustainably-sourced timber remains an attractive proposition for a variety of typologies in the UK. In addition to timber-framed housing, mass timber structures using engineered products such as CLT, GLT and engineered lumbers are versatile, attractive and viable solutions for many educational, health, cultural, and an increasing number of commercial retrofit developments, such as those where upward extensions look to take advantage of lighter weight structural forms.

At Civic Engineers, our own experience of designing timber structures is experiencing and observing the joy that this natural material brings to those designing, constructing, and most importantly those end-users who occupy the completed buildings. There have been recent studies on the positive health and wellbeing benefits of living and working in timber buildings, particularly in the health and wellbeing sector.

Timber construction has, however, over recent years become more challenged by unintended consequences of building regulation changes, insurance risk, nervousness from funders and warranty providers. Commercial viability of mass timber structures in the UK market continues to remain more challenging than that of concrete and steel framing, despite the clear and obvious desire of many developers, government agencies, designers and tenants to build more in timber. All of the timber buildings that our practice has engineered in recent years have been delivered in no small part due to the client’s persistent determination to deliver their building in timber.

Designers, specialist timber constructors and clients often find their ambition tempered when faced with these challenges in the UK market.  However, there remains considerable optimism, energy and positive action amongst the timber engineering community.  This was evident at the Structural Timber Association conference, and evidenced by the recent launch of the Sustainable Timber in Construction (TiC) policy roadmap. Adding to this, the skills and technical resources that are now readily available for the design and construction of innovative new structural timber projects are nothing short of fantastic, thanks to organisations such as Timber Development UK, Built by Nature and the Structural Timber Association.

There is a push for more home-grown structural timber in the UK, captured in an expert presentation at the recent conference. This has to be welcomed, and would benefit from wider industry and government support.  We also need more timber testing data to provide the evidence base for timber in UK construction – perhaps some of the larger developers and timber specifiers can get together to share the cost of this testing alongside public sector support. Built by Nature are doing some good work already in this space to support this endeavour. Ultimately, open-source data sharing between designers, their clients and timber suppliers would also help support this cause.

So this is a call to action from us all, and a reminder that it’s #timefortimber. [Image credit: Citizens Design Bureau]

Timber engineering for a sustainable future: the challenges, opportunities and joy