Andy Hackett of voestalpine Metsec puts the case for putting steel at the core of industry moves towards the goal of net zero carbon 2050, as production begins to evolve away from fossil fuels, and advises a holistic comparison of materials
All parts of the economy are coming under increasing pressure to become more sustainable in their operations as national and international governments push towards Net carbon zero. With the built environment being responsible for a significant proportion of global greenhouse emissions, the construction industry needs to adopt practices which minimise carbon emissions and promote sustainability.
Deciding whether to adopt such processes may not be entirely voluntary either, as central government and local authorities are already putting policies in place to encourage a greener approach, a trend which seems likely to continue in the future.
Together with other environmental initiatives, such as the London Plan 2021, which requires medium and large-scale construction projects in London to have an Environmental Product Declaration (EPD) and carbon footprint statements as part of the planning application, these policies place increased pressure on architects to design buildings which can be constructed using sustainable materials and methods.
As designers and specifiers look to make their projects as sustainable as possible, everyone in the supply chain is placed under increasing scrutiny, from the materials manufacturer to contractors, installers and sub-contractors. Every process will have an impact on the environment in some way and have implications for the carbon footprint of the project. The challenge is to make these processes carbon neutral.
When it comes to materials, the challenges are considerable; the major building materials that are used today, and likely to be used for centuries to come, all have some impact on the carbon content of a building project. This is true of concrete, bricks, steel, plastics and timber.
The carbon content can be from a variety of sources: the natural material’s intrinsic carbon content, the processes used to extract the materials, their conversion into usable raw materials, conversion/production processes and all of the supporting functions that contribute towards a product being used, from sales and administration to storage and transportation.
There is also the question of whether this carbon remains embodied within the material after the life of the building, such as when metals are recovered, recycled and/or repurposed, or released into the environment; for example, where timber cannot be re-used and might be burned.
Steel yourself
- Steel and sustainability might not be a connection that everyone makes immediately, but its credentials make a compelling case for its use in construction, with light gauge steel framing systems (SFS) delivering additional benefits. These include: steel is easily recoverable and is 100% recyclable – SFS has a reuse and recovery rate of 85%, compared to just 13% for timber;
- reduction in a structure’s embodied carbon by using less steel;
- accurate design and manufacturing processes result in virtually zero waste;
- SFS is a lighter material, reducing the environmental impact of transportation.
There is no escaping the fact that steel manufacture is one of the largest global contributors to carbon dioxide emissions, but European steel manufacturers are making great strides to move away from fossil-fuelled processing by using less carbon-intensive electric arc furnaces which are powered by renewable energy to create a reduced carbon steel.
A few steel systems manufacturers now include this as an option for their product ranges; our own Metsec Decarb being one example. It is available on our SFS ranges, internal non-load bearing dry lining studs and purlins.
This steel is a true move towards a reduced carbon future for the construction industry. It does not rely on the smokescreens of greenwashing, mass balance, carbon offsetting or the allocation of green energy for its environmental credentials, but instead stands by its own impressive outputs; compared to blast furnace manufactured steel. Figures as of July 2024 show Metsec Decarb typically contains less than half the amount of carbon dioxide per tonne for the same quality of steel.
Beyond material concerns
The carbon within the material itself makes a significant impact on the carbon content of the building. However, as mentioned, there are many additional inputs which can contribute towards the environmental impact of the building and the materials used in it; the processes used in manufacturing, administration, storage and distribution. There seems little point in a building materials/systems manufacturer offering a reduced carbon product if the same manufacturer is not committed to reducing the carbon dioxide emissions of its own operations.
Net zero carbon remains part of the government’s procurement policy. The previous adminstration’s Cabinet Office Action Note PPN06/21 stipulated how government departments need to take account of suppliers’ net zero carbon reduction plans when procuring major government contracts.
While governments at home and abroad have wavered on their commitment to achieving net carbon zero emissions by 2050, there can be little doubt that the objective will remain an integral part of UK policy in the future, even if the deadline is extended.
Manufacturers and suppliers will still need to look at ways in which they can reduce their carbon emissions; as part of voestalpine AG, Metsec remains committed to achieving net zero carbon emissions by 2035.
A carbon guarantee
As with most things in life, achieving a desired result, in this case a net zero carbon building, will rely on striking a balance between the ideal and the achievable.
Faced with a design brief to minimise a building’s carbon footprint, steel might not be the first building material which comes to an architect’s mind. But, on closer inspection, steel, and reduced carbon steel in particular, offers a viable solution when all factors are considered, especially when used in the manufacture of efficient construction solutions.
Specifiers can take added assurance of product/system credentials from manufacturer statements and EPDs which can be included in the final project’s carbon assessments.
Andy Hackett is general manager & director at voestalpine Metsec Dry Lining Division