Steel has strong green credentials, says Corus

Steel manufacturer Corus has defended steel’s environmental credentials as a building material.

At a recent seminar, the company outlined a raft of arguments  to encourage people to look beyond the metal’s
high embodied CO2 levels. Steel requires the emission of 1.1t of CO2 for every tonne of metal produced; the comparable figure for concrete is 0.16t.

But Professor Roger Plank of Sheffield University insisted there were more elements to sustainability than just embodied CO2. “The ratio of embodied energy to operational energy is about 10:1 for a highly serviced building,” he said. “Designing buildings to minimise energy consumption in use is therefore much more important than minimising embodied energy.”

The ability to recycle steel and its role in reducing the waste associated with construction were also highlighted as important sustainable characteristics.

“Steel is the world’s most recycled material,” said Walter Swann, regional technical manager. “More than 80% of scrap is captured and recycled worldwide.” When combined with re-use rates of up to 15% for some products, this means very little steel waste goes to landfill.

“There is also no waste generated on site as it is all pre-ordered  and pre-engineered to the required dimensions,” said Dr Michael Sansom of the Steel Construction Institute.

There is also little waste from the production process, he said. “More than 90% of the by-products of steel making, such as blast furnace slag, can be and are used, notably in construction .”