Considering the end of a product’s life cycle changes how you design with that product
An increasing number of material suppliers, including many steel makers, provide EPDs. Industry average EPDs are available, while the IStructE also provides its own guidance.
Not all EPDs have the same scope, however, and a number of them disregard the end of life stage.
End of life scenarios are part of a ‘whole life carbon’ approach. It can be difficult to imagine what might happen to a building in 50 or 60 years’ time, but minimising the environmental impact of deconstruction, and reducing waste processing and disposal as much as possible, is an essential part of sustainable design.
Ignoring this stage doesn’t paint a true picture of the potential impact of the construction product, and the building in which it is used, through the whole life cycle. So where to look for information, and how to compare that information? Are there some simple rules of thumb which can help?
For starters, EPDs should be third-party verified (Type III) and produced in accordance with the relevant ISO standards (EN ISO 14025 and 15804). Even then, however, there can be significant differences in what is actually reported.
If looking just at Modules A1 to A3 for different steel products, some very different values for CO2 equivalent emissions are likely to be found. This can be based on the steel-making technology used, and whether it was produced by the EAF or BOS method. By contrast, looking at the whole life impact shows the reported emissions of different steel products to be much more aligned.
At design stage, when the steel supplier is unknown, this means it is usually better to consider all steel products as similar from the point of view of CO2 emissions. The IStructE provides guidance on typical figures to help with the design stage but, just as important, is availability in the local market.
When specifying hollow sections, the Celsius® design app can give some peace of mind in this regard. Only section sizes produced by Tata Steel, and supplied through our extensive distribution network, are included, with an availability indicator for each section size.
Efficient designs can therefore be specified in the knowledge that they’re unlikely to be changed once they get to the procurement stage.