---
title: "Natural Slate - GWP and renovation use"
canonical_url: https://fremtidenstegnestue.dk/en/knowledge/materials/naturskifer
markdown_url: https://fremtidenstegnestue.dk/en/knowledge/materials/naturskifer.md
author: "Fremtidens Tegnestue"
page_type: material
primary_intent: "Explain use, GWP and renovation relevance for Natural Slate."
primary_keyword: "Natural Slate"
audience: "Homeowners, studios and agents researching material choices."
summary: "Natural slate is split shale stone — one of the oldest and most durable roofing materials. Lifespan of 100–150 years or more. The low carbon footprint is because production is primarily mechanical splitting, not thermal treatment. Used on historic buildings and as premium roofing."
source_basis:
  - "ECO Platform EPD 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/betontagsten
    relation: alternative-material
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/materials/tagpap
    relation: alternative-material
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/materials/tagfolie
    relation: alternative-material
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/materials
    relation: hub
  -
    url: https://fremtidenstegnestue.dk/en/knowledge/concepts/lca
    relation: concept
status: published
---
# Natural Slate - GWP and renovation use
Canonical URL: https://fremtidenstegnestue.dk/en/knowledge/materials/naturskifer
Markdown URL: https://fremtidenstegnestue.dk/en/knowledge/materials/naturskifer.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
Natural slate is split shale stone — one of the oldest and most durable roofing materials. Lifespan of 100–150 years or more. The low carbon footprint is because production is primarily mechanical splitting, not thermal treatment. Used on historic buildings and as premium roofing.
## 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 | 0.058 kg CO₂-eq/kg |
| Density | 2700 kg/m³ |
| Expected lifetime | 100–150+ years |
## Use

- Historic and heritage buildings
- Pitched roofs with inclination 30–60°
- Premium residential construction
- Facade cladding
## Renovation relevance
Natural slate is a classic choice for renovating historic buildings and listed properties. It is the roofing material with the lowest carbon footprint and the longest lifespan.
## Comparison

| Material | GWP |
| --- | --- |
| Natural slate | 0.058 |
| Concrete roof tile | 0.25 |
| Roofing felt | 1.2 |
| Roofing membrane | 2.5 |
## FAQ
### Where does natural slate come from?
Mostly from Spain (Galicia), Wales, and Brazil. Spanish slate is the most widely used in Denmark. Quality varies — look for S1 or T1 classification for the best durability.
### Is natural slate expensive?
Yes — natural slate costs 2–3x more than concrete tiles in material cost. But with a lifespan of 100+ years, it is actually cheaper per year of service than most alternatives.
### Does slate require maintenance?
Minimal. Slate tiles are robust and rarely need repair. Nails and the wooden battens holding the tiles can rust and rot after 40–60 years and require periodic inspection.
### Is natural slate suitable for all roof types?
Natural slate requires adequate pitch (min. 25–30°) and a structure that can bear the weight (approx. 30–50 kg/m²). It is not suitable for flat roofs.
## Sources and basis
- ECO Platform EPD 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
- [Concrete Roof Tiles](https://fremtidenstegnestue.dk/en/knowledge/materials/betontagsten): alternative-material
- [Roofing Felt](https://fremtidenstegnestue.dk/en/knowledge/materials/tagpap): alternative-material
- [Roof Membrane (TPO/EPDM)](https://fremtidenstegnestue.dk/en/knowledge/materials/tagfolie): 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/naturskifer) 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.