What is circularity? Understanding steel’s role in a circular economy

Principles of circularity

A circular economy is a system where resources and materials are kept in use for as long as possible, then repaired, returned, refurbished, or recycled so their value is retained.

The role of steel in a circular economy

Steel plays an important role in the circular economy. The steel we supply today will support economies for decades to come and is critical in underpinning the transformation to a low-carbon economy, for example, through renewable energy infrastructure.

Steel can be a highly valuable circular material when products are designed for durability and steel components are engineered for easy disassembly and reuse. Resource usage can be reduced through the dematerialisation of building designs and adaptive reuse, which involves repurposing existing buildings. Steel products can also retain their value across lifecycles through repair and refurbishment, and steel can be recycled indefinitely without losing any quality.

Steel also contributes to the circular economy through the effective reuse of manufacturing outputs. For example, its co-products, such as blast furnace slag, are key ingredients in concrete.

Importance of circularity

As circularity becomes an increasing priority, there are several Circular Economy policies and recommendations available in Australia. The Green Building Council of Australia provides a Practical Guide to Circular Procurement detailing circularity strategies and their benefits for new buildings and major refurbishments. They state that the benefits of circular procurement for buildings could include reduced material cost, extended asset value, economic growth and environmental benefits.

Circularity initiatives have also become an important consideration in rating tools and certifications. Both Green Star and the Infrastructure Sustainability (IS) Rating Scheme encourage the reuse of steel, as well as the procurement of steel with Environmental Product Declarations. The National Australian Built Environment Rating System (NABERS) embodied carbon tool values circularity by considering reused materials as having zero embodied carbon.