Timber as a sustainable building material

As reported by Reuters, the use of timber in construction is gaining traction worldwide.

Notable projects such as a 5,000-seat football stadium in the UK, a replacement terminal at Zurich airport, the Naples central underground station, and the aquatic centre for the Paris 2024 Olympic Games all feature timber as the primary construction material.

Mass timber products, including cross-laminated timber (CLT), glulam, and laminated veneer lumber, are becoming popular due to their benefits in strength, flexibility, and sustainability.

The need to decarbonise cities is a significant driving force behind the adoption of timber in construction.

The built environment sector is responsible for 37% of global emissions, largely due to the use of high-emission materials like concrete and steel.

Studies indicate that replacing these materials with mass timber could reduce global CO2 emissions by 14-31% and fossil fuel use by 12-19%.

Addressing fire safety and sustainability concerns

One of the primary concerns regarding the use of timber is fire safety.

According to Built by Nature (BbN), mass timber products are combustible but behave predictably in fires, and various fire prevention measures can be applied.

The UK, following the Grenfell fire disaster in 2017, has stringent fire regulations that limit the use of combustible materials in buildings over 18 metres tall.

This has reduced the residential market for mass timber in the UK, although it remains popular for sports facilities and schools.

Sustainability concerns also play a role in the adoption of mass timber.

While proponents argue that timber is a renewable resource, the United Nations Environment Programme (UNEP) warns that the CO2 reduction potential of timber has been overestimated.

The sustainability of timber depends on responsible harvesting and replanting practices, which vary globally.

In the UK, most engineered wood products are certified by the Forest Stewardship Council (FSC) or the Programme for the Endorsement of Forest Certification (PEFC).

Innovations and policies promoting timber use

Various innovations are being explored to address the challenges of using timber in construction.

For instance, hybrid wood products combining hard and soft woods are being developed to reduce reliance on single species like Sitka spruce, which can improve biodiversity and carbon storage.

Additionally, the EU-funded Woodcircles project aims to enhance the recyclability and reuse of timber in buildings.

Policies are also being implemented to incentivise the use of timber.

Cities like Amsterdam and Hamburg have set mandates and subsidies to promote mass timber construction.

Outside Europe, Toronto allows mass timber buildings up to 12 storeys, and New York City is actively promoting the benefits of timber construction.

National-level policies in countries like Australia and France further support the adoption of timber through financial incentives and legislative measures.

The future of timber in construction

The future of timber in construction looks promising as awareness of its environmental benefits grows.

Policymakers and industry stakeholders are increasingly recognising the potential of timber to reduce the construction sector’s environmental footprint.

Andrew Lawrence, global timber specialist at Arup, emphasised the need for consensus on fire safety and water damage solutions to build confidence in timber construction.

IFSJ Comment

As cities worldwide strive to reduce their carbon footprints, timber offers a viable alternative to traditional materials like concrete and steel.

However, the adoption of timber is not without its challenges.

Fire safety concerns, sustainability issues, and the need for industry-wide knowledge and acceptance are significant hurdles that must be addressed.

Innovations such as hybrid wood products and research into biomass-based glues show promise in overcoming some of these challenges.

Moreover, policies at both city and national levels are crucial in promoting the use of timber.

Mandates, subsidies, and legislative measures are driving the adoption of mass timber, particularly in regions where awareness and expertise are already established.