Which has lower embodied carbon — timber or steel?

Timber has significantly lower embodied carbon than steel. Typical values per kg of material: structural steel 1.2–2.5 kgCO₂e/kg, structural timber (sawn) 0.2–0.5 kgCO₂e/kg (excluding biogenic carbon).

Timber has significantly lower embodied carbon than steel. Typical values per kg of material: structural steel 1.2–2.5 kgCO₂e/kg, structural timber (sawn) 0.2–0.5 kgCO₂e/kg (excluding biogenic carbon). When biogenic carbon storage is included, timber becomes carbon-negative: each kg of timber stores approximately 1.8 kgCO₂e while emitting only 0.2–0.5 kgCO₂e in processing. On a per-building basis, a timber-framed building typically has 40–70% lower embodied carbon than an equivalent steel-framed building, depending on design and methodology.

Why this matters

This question relates to Timber vs Steel: Full Lifecycle Environmental Comparison, 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:

→ Timber vs Steel: Full Lifecycle Environmental Comparison

Related questions

• Is steel more recyclable than timber?
• How do timber and steel compare for operational energy?
• What about the land use impact of timber production?

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.