How is biogenic carbon reported in timber EPDs?

Under EN 15804+A2, biogenic carbon must be reported separately from fossil carbon. At module A1 (forestry), the carbon absorbed by the tree during growth is reported as a negative value (carbon uptake, typically −1.5 to −1.8 kgCO₂/kg for softwood).

Under EN 15804+A2, biogenic carbon must be reported separately from fossil carbon. At module A1 (forestry), the carbon absorbed by the tree during growth is reported as a negative value (carbon uptake, typically −1.5 to −1.8 kgCO₂/kg for softwood). At end-of-life (module C3 or C4), this stored carbon is released and reported as a positive value. The net biogenic carbon over the full lifecycle is zero (what goes in must come out). However, during the product's service life (potentially 50–200 years for structural timber), the carbon remains stored — this temporal storage benefit is the basis of timber's climate advantage.

Why this matters

This question relates to EPD (Environmental Product Declaration) for Timber: How to Read It, which covers the broader topic in detail. Understanding this specific aspect helps architects, builders, and timber dealers make informed specification decisions.

For full context and additional technical detail, see our comprehensive guide:

→ EPD (Environmental Product Declaration) for Timber: How to Read It

Related questions

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About this answer

This answer is part of the PuurModulair Knowledge Base — comprehensive timber specification guidance for architects, builders, and dealers across the UK, EU, and Scandinavia.