What is Module D and why does it matter for timber?

Module D in EN 15978 reports the 'benefits and loads beyond the system boundary' — essentially the environmental credits from reuse, recycling, or energy recovery at end of life. For timber, Module D can include: carbon stored in recycled timber products, avoided emissions from displacing fossil fuels (if timber is used as biomass), and avoided emissions from displacing virgin materials.

Module D in EN 15978 reports the 'benefits and loads beyond the system boundary' — essentially the environmental credits from reuse, recycling, or energy recovery at end of life. For timber, Module D can include: carbon stored in recycled timber products, avoided emissions from displacing fossil fuels (if timber is used as biomass), and avoided emissions from displacing virgin materials. Module D is reported separately from Modules A–C and is not included in the whole-life carbon total, but it significantly favours timber over non-renewable materials.

Why this matters

This question relates to Embodied Carbon in Timber Construction: Calculation Methods, 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:

→ Embodied Carbon in Timber Construction: Calculation Methods

Related questions

• What is embodied carbon in timber construction?
• How do you calculate embodied carbon for timber?
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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. All technical content is reviewed by qualified timber technologists before publication.