With all structures having a carbon footprint, a challenge faced by the construction industry is the range of assumptions used in carbon and life-cycle calculations that compare material options and designs - including for steel. Currently there are several calculators, each with assumptions and data references that tell a different story.
Working with colleagues in Sweden and the UK, WSP NZ is talking with government agencies about the development of an agreed set of assumptions and rules. Once we have that, we’ll have a better view on how best to make sure the carbon impact of steel in built structures is within carbon limits.
Meanwhile, there are some important things we can do when designing with steel to make sure structures have lower 'embodied' and operational carbon emissions - for instance, minimising onsite waste, increasing the opportunity to repurposing structures, reusing and recycle steel, and enhancing passive insulation in buildings.
You don’t always have to go big, just simply tweaking here and there contributes to reducing the embodied carbon of a structure. Individually, these changes may appear minuscule, but compound these and up to 50% carbon savings can be achieved.
No matter how you look at it, decarbonising our structures will remain a major challenge. But by harnessing innovations in the construction of our built environment, including with recycled and more sustainably manufactured steel, designers and engineers are well placed to deliver solutions that will drive down emissions and help lessen the impacts of climate change.