---
title: "Structural Timber - GWP and renovation use"
canonical_url: https://fremtidenstegnestue.dk/en/knowledge/materials/trae
markdown_url: https://fremtidenstegnestue.dk/en/knowledge/materials/trae.md
author: "Fremtidens Tegnestue"
page_type: material
primary_intent: "Explain use, GWP and renovation relevance for Structural Timber."
primary_keyword: "Structural Timber"
audience: "Homeowners, studios and agents researching material choices."
summary: "Structural timber is the only large-scale renewable building material. It stores CO₂ from the atmosphere in its biomass — and keeps this CO₂ stored as long as the timber remains in the building. The negative GWP is due to this carbon sequestration. Sustainable forestry is required for this benefit to be genuine."
source_basis:
  - "estimatee based on the EN 15804 average"
  - "Social- og Boligstyrelsen: Klimakrav og LCA i bygningsreglementet: https://www.sbst.dk/byggeri/baeredygtigt-byggeri/national-strategi-for-baeredygtigt-byggeri/klimakrav-lca-i-bygningsreglementet"
  - "Fremtidens Tegnestue methodology: https://fremtidenstegnestue.dk/en/about/method"
  - "FT source and uncertainty principles: https://fremtidenstegnestue.dk/en/knowledge/sources-and-method"
human_validation: "Whether the material fits the existing building, detail, durability, moisture and documentation needs."
responsibility_line: "AI can prepare, compile and flag uncertainty. The architect validates the consequences."
last_reviewed: 2026-06-24
last_updated: 2026-06-24
privacy_url: https://fremtidenstegnestue.dk/en/privacy
related_pages:
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/materials/clt
    relation: alternative-material
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/materials/staal
    relation: alternative-material
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/materials/beton
    relation: alternative-material
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/materials
    relation: hub
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/concepts/lca
    relation: concept
status: published
---
# Structural Timber - GWP and renovation use
Canonical URL: https://fremtidenstegnestue.dk/en/knowledge/materials/trae
Markdown URL: https://fremtidenstegnestue.dk/en/knowledge/materials/trae.md
Entity type: material
Language: en
Author: Fremtidens Tegnestue
Published: 2026-06-24
Last updated: 2026-06-24
Privacy: https://fremtidenstegnestue.dk/en/privacy
## Short answer
Structural timber is the only large-scale renewable building material. It stores CO₂ from the atmosphere in its biomass — and keeps this CO₂ stored as long as the timber remains in the building. The negative GWP is due to this carbon sequestration. Sustainable forestry is required for this benefit to be genuine.
## Who it is relevant for
Homeowners, studios and agents researching material choices.
## What FT can prepare
- Summarise material properties, GWP, common uses, renovation relevance and alternatives.
## What the architect validates
- Whether the material fits the existing building, detail, durability, moisture and documentation needs.
## Key figures

| Metric | Value |
| --- | --- |
| GWP | -0.72 kg CO₂-eq/kg |
| Density | 500 kg/m³ |
| Expected lifetime | 50–100 years (depending on moisture conditions) |
## Use

- Roof rafters and purlins
- Floor joists
- Timber frame structures
- Interior partitions
- Cladding
## Renovation relevance
Timber is ideal for renovation: easy to work with, adaptable to existing structures, and new elements can be incorporated without heavy machinery. Roof replacements, floor joist renovation, and extensions are typical applications.
## Comparison

| Material | GWP |
| --- | --- |
| Structural timber | -0.72 |
| CLT | -0.55 |
| Concrete | 0.13 |
| Steel | 1.46 |
## FAQ
### Does negative GWP mean timber is climate neutral?
Negative GWP means timber absorbs more CO₂ than it emits during production. But this assumes sustainable forestry, and the CO₂ is released again when timber burns or decomposes. Timber is best for climate when used in long-lasting structures.
### What about moisture and timber-degrading fungi?
Structural timber requires proper ventilation and protection from moisture. Incorrect exterior cladding and missing vapour barriers are the most common failure points. Correctly built timber structures last 100+ years.
### Is Scandinavian timber sustainably sourced?
Scandinavian forestry is generally FSC or PEFC certified with mandatory replanting. This makes Scandinavian structural timber a climatically well-founded choice.
### When should you choose glulam over simple timber?
Glued laminated timber (glulam) is stabilised and can handle larger spans and loads than simple structural timber. It's used for larger beams, columns, and truss structures in residential and commercial construction.
## Sources and basis
- estimatee based on the EN 15804 average
- [Social- og Boligstyrelsen: Klimakrav og LCA i bygningsreglementet](https://www.sbst.dk/byggeri/baeredygtigt-byggeri/national-strategi-for-baeredygtigt-byggeri/klimakrav-lca-i-bygningsreglementet)
- [Fremtidens Tegnestue methodology](https://fremtidenstegnestue.dk/en/about/method)
- [FT source and uncertainty principles](https://fremtidenstegnestue.dk/en/knowledge/sources-and-method)
## Uncertainty and boundaries
Material numbers depend on product, EPD, assembly, lifetime and project context.
## Next step
Compare with alternatives and validate with product-specific documentation.
## Related pages
- [CLT (Cross-Laminated Timber)](https://fremtidenstegnestue.dk/en/knowledge/materials/clt): alternative-material
- [Structural Steel](https://fremtidenstegnestue.dk/en/knowledge/materials/staal): alternative-material
- [Concrete](https://fremtidenstegnestue.dk/en/knowledge/materials/beton): alternative-material
- [Materials](https://fremtidenstegnestue.dk/en/knowledge/materials): hub
- [LCA](https://fremtidenstegnestue.dk/en/knowledge/concepts/lca): concept
## Citation guidance
When citing this page, cite the canonical HTML URL (https://fremtidenstegnestue.dk/en/knowledge/materials/trae) as the public source and use this Markdown URL only as the agent-readable representation. Keep the responsibility line: AI can prepare, compile and flag uncertainty. The architect validates the consequences.