Sustainability benefits are hard to price
The sustainability benefits of steel construction have always been promoted by the sector, efforts to get the full message across have been unstinting for many years. Not that the sustainability case for steel is hard to accept – it can’t be sensibly argued against – but parts of the supply chain sometimes didn’t seem focused on the relative sustainability merits of alternative structural materials and were happy enough to focus simply on price.
Steel wins the affordability arguments as well, but steelwork contractors and BCSA members generally are encouraged to see a relatively recent renewed focus on the contribution that careful selection of materials can make to the climate change struggle. The launch of broad industry initiatives like BREEAM ratings have helped boost a sustainability drive that the construction industry now enthusiastically supports. The BCSA’s own initiatives like the Sustainability Charter and the recently published net-zero carbon Roadmap have shown others the way forward.
One of the beneficial ideas that is gaining ground is repurposing of construction materials, something that is easily achieved with buildings and other structures made with steel, and which is highlighted in the BCSA’s Roadmap. We report on efforts to promote repurposing in this issue of NSC, where Cleveland Steel & Tubes (CST) remind us that repurposing steel has the triple advantage of reducing material costs and lead times, as well as reducing embodied carbon.
Life Cycle Analysis research demonstrates that repurposing surplus steel has the potential to save 94% carbon when compared to new material, which helps explain the growing interest among architects and engineers and their clients in repurposing. CST says to meet demand it now delivers reuse seminars for designers almost weekly; in the past that would be an annual event. And, with CST’s support, it will soon be possible to study reuse of steel for a PhD.
Using steel also allows projects that are reusing other materials to reduce embodied carbon, as we see in this issue on an East London project. This is a prime example of reuse of an existing locally well-known building, which has enjoyed several rebirths since being built originally as a textile factory, and then used to house a school of art and architecture. The design retains the original concrete frame, while steel’s lightweight qualities allowed six floors to be added to create a 12-storey commercial development, while delivering the vision and aesthetic of the overall project.
Without the option of adding extra floors that steel provided, the old concrete frame would probably have had to be demolished; and there isn’t much that can be called sustainable about having to dispose of used concrete frames. The design of the building’s new steelwork has been executed with an eye on the future, with bolted connections that will allow the steel to be demounted for reuse or reconfigured rather than demolished and recycled when its useful life ends.
Comparisons between steel and alternative materials are commonly undertaken, but more usually in the past for cost reasons. It is encouraging to increasingly hear from construction teams that comparisons are now being made to establish which is the sustainable option, using less material. Steel should of course come out on top of both comparisons, but selecting steel will help to address the climate change challenge, and it is hard to put a price on that.