--- title: "Structural Steel - GWP and renovation use" canonical_url: https://fremtidenstegnestue.dk/en/knowledge/materials/staal markdown_url: https://fremtidenstegnestue.dk/en/knowledge/materials/staal.md author: "Fremtidens Tegnestue" page_type: material primary_intent: "Explain use, GWP and renovation relevance for Structural Steel." primary_keyword: "Structural Steel" audience: "Homeowners, studios and agents researching material choices." summary: "Structural steel is one of the most commonly used materials for load-bearing structures. It's strong, precise, and can be recycled almost indefinitely. Carbon footprint varies significantly depending on production method — electric arc furnace steel (from recycled scrap) has a markedly lower footprint than primary blast furnace steel." source_basis: - "ECO Platform EPD average (primary steel)" - "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/trae relation: alternative-material - url: https://fremtidenstegnestue.dk/en/knowledge/materials/clt 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 Steel - GWP and renovation use Canonical URL: https://fremtidenstegnestue.dk/en/knowledge/materials/staal Markdown URL: https://fremtidenstegnestue.dk/en/knowledge/materials/staal.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 steel is one of the most commonly used materials for load-bearing structures. It's strong, precise, and can be recycled almost indefinitely. Carbon footprint varies significantly depending on production method — electric arc furnace steel (from recycled scrap) has a markedly lower footprint than primary blast furnace steel. ## 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 | 1.46 kg CO₂-eq/kg | | Density | 7850 kg/m³ | | Expected lifetime | 100+ years | ## Use - Load-bearing columns and beams - Roof structures - Bridges and large structures - Facade elements - Stairs ## Renovation relevance Steel is used in renovation for reinforcing existing structures, extensions, and roof structures. Prefabricated steel systems provide rapid installation with minimal disruption to existing construction. ## Comparison | Material | GWP | | --- | --- | | Primary steel | 2.2 | | Recycled steel | 0.6 | | Concrete | 0.13 | | CLT | -0.55 | ## FAQ ### What's the difference between primary and recycled steel? Primary steel (from blast furnace) has a GWP of approximately 2.0–2.5 kg CO₂/kg. Electric arc furnace steel from recycled scrap has approximately 0.4–0.8 kg CO₂/kg — up to 5 times lower. This is a significant difference that should be reflected in material selection. ### Can steel be recycled? Steel is one of the world's most recycled materials. Over 85% of steel in buildings ends up as recycled scrap. In practice, recycled content percentage should always be specified in climate calculations. ### Is steel better than concrete climatically? It depends on context. Steel has higher GWP per kg, but you typically use much less steel than concrete in a structure (steel is stronger). Total climate impact per structural unit can be comparable. ### When do you choose steel over concrete? Steel is ideal for large spans (halls, industry, bridges), complex geometries, prefabrication, and tight timelines. It's easier to disassemble than concrete, enabling element reuse at demolition. ## Sources and basis - ECO Platform EPD average (primary steel) - [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 - [Structural Timber](https://fremtidenstegnestue.dk/en/knowledge/materials/trae): alternative-material - [CLT (Cross-Laminated Timber)](https://fremtidenstegnestue.dk/en/knowledge/materials/clt): 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/staal) 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.