Minimising greenhouse gas emissions in structural timber construction

This technical position paper from the Institution of Structural Engineers outlines strategies for minimising greenhouse gas emissions when designing and specifying timber. By looking at how structural timber can contribute to carbon emissions, this study identifies key considerations for reducing these impacts, and provides recommendations for designers and policymakers.

What’s the Issue?

Structural timber is increasingly used in construction to reduce embodied carbon. While timber stores biogenic carbon during its life, its climate benefit depends on how it is sourced, used, and managed at end-of-life. Inefficient use or premature disposal can undermine its potential to support net zero goals.

Key Issues in Biogenic Carbon Accounting

Environmental Product Declarations (EPDs) provide transparent data on a product’s environmental impact. Including biogenic carbon in wood EPDs ensures accurate reporting of carbon storage and emissions. This information helps architects and developers compare materials and choose low-carbon options. There are key issues in reporting biogenic carbon:

Maximising Biogenic Carbon Sequestration
- Forests absorb and store carbon; sustainable sourcing and afforestation are essential.
- Long-term storage in timber products is critical—burning timber releases more emissions per unit of energy than fossil fuels.
Using Timber Efficiently
- Treat timber as a finite resource; design for efficient spans and lightweight structures.
- Avoid over-specification and prioritise low-rise, short-span applications.
Prioritising Long-Life
- Extend the lifespan of timber through reuse, durable detailing, and adaptability.
- Divert timber from short-life uses and burning to long-life structural applications.

Why This Matters

Timber can play a major role in reducing global emissions, but only if used responsibly. Misinterpretation of biogenic carbon benefits or inefficient design could lead to higher emissions and resource strain. Policies and practices must balance timber demand with forest protection and long-term carbon storage.

Recommendations for Practitioners

Set realistic carbon limits and explain sequestration concepts to clients.
Separate upfront emissions and biogenic sequestration in carbon accounting.
Design for efficiency and durability, using reclaimed or lower-grade timber where possible.
Source timber sustainably through schemes like FSC, PEFC, or Grown in Britain.

Recommendations for Policymakers

Forecast timber demand and integrate forestry emissions into net zero strategies.
Incentivise efficient, long-life timber use and discourage burning.
Support innovation, reclaimed timber markets, and improved building regulations.
Ensure sustainable sourcing and afforestation policies.

For a deeper dive, download the report on this page.

Date: November 2025