Benefits of the circular economy
Steel has excellent circular economy credentials both as a material
which is strong, durable, versatile and recyclable and as a structural
framing system which is lightweight, flexible, adaptable and
reusable. Steel’s combination of strength, recyclability, availability,
versatility and affordability makes it unique.
A circular economy promotes long product lives. Maintaining
products at their highest utility and value for as long as possible, is
a key component of the circular economy. Put simply, the longer
a product lasts the less raw materials will need to be sourced and
processed and less waste generated.
Properly designed and, where appropriate, properly protected
steel structures provide long-term durability. Buildings like the
National Liberal Club in London (1887) and structures like the Forth
Rail Bridge (1890) demonstrate the longevity of steel buildings and
Steel-framed buildings are among the most adaptable and
flexible assets a business can invest in. The steel frame itself can be
easily adapted, with parts added or taken away, and its light weight
means that extra floors can often be added without overloading
Steel structures are commonly used to renovate buildings for
example behind retained façades. In this way the historic value,
character and resources of the façade are retained and the building
structure can be reconfigured to create open, flexible internal
space that meets modern client requirements and maximises net
lettable floor area.
Steel is strong and has a good strength-to-weight ratio.
Compared to other commonly used structural materials, steel
buildings are lightweight meaning that significantly fewer
materials are required to construct them.
Steel’s two key components are iron ore, one of Earth’s most
abundant elements, and recycled (scrap) steel. Once steel is
produced (from iron ore) it becomes a permanent resource for
society; as long as it is recovered at the end of each product life
cycle, because it is 100% recyclable without loss of quality.
In theory, all new steel could be made from recycled steel.
However, this is not currently possible because global demand for
steel exceeds the supply of scrap. This imbalance is due to steel’s
global popularity and its durability; meaning that an estimated
75% of steel products ever made are still in use today.
Steel products in use today all contain a proportion of recycled
steel from previous incarnations; this can be one or many previous
uses. Originally this ‘recycled’ steel was produced from iron ore
and therefore how the initial impacts of primary production are
shared over subsequent uses of the same material is an important
question in quantifying its whole life environmental impacts.
Reuse and remanufacture
Reusing simple, low-rise structures such as portal frames,
is relatively common particularly in the agricultural sector.
Larger, whole building reuse is less common but there are
some examples where this has worked well.
One such example is the International Aviation Academy,
Norwich, where an historic steel-framed hangar is being
refurbished into a new academy specialising in education
and skills in aviation.
Component, i.e. beam or column, reuse is currently
relatively rare but there are very real prospects of this
changing soon. BIM technologies overcome several of the
barriers to steel reuse by providing certainty about material
properties, traceability and provenance and eliminating the
need for testing.
Looking ahead therefore, structural steel (BIM) models
offer a cost-effective means of enabling future reuse.
The ability to reuse building components is, to a large
extent, dependent on how buildings have been constructed
in the first place. Although designers routinely consider
the constructability of buildings, historically little thought
is given to their deconstruction and how elements and
components could be reclaimed and reused.
At its simplest level, there are two main considerations:
1. The types of materials and components used; some
products, like structural steel, are inherently more reusable
than other structural materials and systems.
2. The way the materials and components are put together
(thus able to be taken apart) and deconstructed.
What next for steel and the circular economy?
The circular economy is an important, evolving agenda.
However, the need to move towards a more circular economy
is not in doubt nor are the potential economic opportunities.
Steel, both as a material and a structural framing system,
already has excellent circular economy credentials, inherent
attributes that cannot be matched by competing structural
materials. Structural steel also has the advantage that it
can go further and deliver truly circular demountable and
New legislation, technical developments and different
business models are required to realise these opportunities,
but the steel sector is ready and working in partnership with
its supply chain to deliver the circular economy.
Further details on steel and the circular economy are
available at: www.steelconstruction.info/Steel_and_the_
Model of steelwork;
Grey: Existing roof steelwork
Blue: New roof steelwork
Purple: New feature and
Orange: New mezzanine and
classroom roof steelwork