Structure

Structural Steel.

Steel has a high CO₂ footprint per kg, but is strong and recyclable. Always specify recycled content — it makes a significant difference to the carbon accounting.

Key Figures

Carbon Footprint (GWP): 1.46 kg CO₂-eq/kg
Density: 7850 kg/m³
Expected Lifespan: 100+ år

What is structural steel?

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.

Carbon Footprint Compared

Primary steel ← this material 2.2 kg CO₂/kg

Recycled steel 0.6 kg CO₂/kg

Concrete 0.13 kg CO₂/kg

CLT −0.55 kg CO₂/kg

Negative carbon footprint (green) indicates carbon storage. Data based on EPD averages from ECO Platform and estimates per EN 15804.

Typical Applications

check_circle Load-bearing columns and beams
check_circle Roof structures
check_circle Bridges and large structures
check_circle Facade elements
check_circle Stairs

In Renovation

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.

Questions about structural steel

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.

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