The construction industry has a reputation for being slow to change — “this is how I’ve done it for years” is a familiar phrase in project meetings. But from a materials perspective, things are shifting fast. We’re seeing steady reductions in the carbon footprint of concrete, steel, and timber, thanks to new technologies and smarter processes.
Concrete – The usual suspect
Concrete is the second most used material in the world, behind water, yet it faces the most criticism because cement production is so carbon-intensive; producing 1kg of Portland Cement generates an equal amount of CO2 emissions. But improvements are already here. Here are some current and future technologies we are excited about:
- Substituting Supplementary Cementitious Materials (SCMs) – Many concrete mixes now substitute in Supplementary Cementitious Materials, waste products from other industrial processes, which significantly reduce their carbon footprint.
- A new zero-carbon cement plant – Heidelberg Materials will be opening a zero-carbon cement plant in Alberta, Canada. With a proof of concept already operational in Norway, this will allow concrete buildings with a carbon footprint comparable to, or even lower than your most efficient timber structures. (More here)
- Recycling cement in electric arc furnaces – Researchers at the University of Cambridge are piloting a system to recycle cement in electric arc furnaces (EAF), turning rubble into fresh cement powered by clean electricity. (More here )
For a broader view, the Institution of Structural Engineers has an excellent tracker of emerging concrete technologies.
Steel – Endlessly recyclable if there’s enough of it
Most of the decarbonization in the steel industry involves switching from Basic Oxygen Furnaces (BOF), which burn fossil fuels for energy, to EAFs, which can be as clean as the energy grids that power them.
New EAF mills are opening regularly across North America, and offerings like Arcellor Mittal’s XCarb steel now make low-carbon steel readily available. The challenge? Scrap steel. Global demand for steel is more than three times the available scrap supply. Still, in North America and Europe, most new steel already comes from EAFs, and as power grids decarbonize, the emissions footprint will continue to shrink.
Timber—Storing carbon as you build
Timber often gets the best press, and for good reasons. As trees grow, they absorb carbon, which stays stored in the wood until the building is demolished (where the wood is reused, burned for power, or left to decompose in landfill). With mass timber technologies, we can now use it for mid- and high-rise buildings, not just houses.
Most emissions from timber come from logging and milling, but these processes are also electrifying and adopting renewable power. Forestry practices are improving, too, helping reduce environmental impacts. Like steel, timber’s footprint is on a steady downward trend.
Are buildings always going to be bad for the planet?
Of course, the greenest building is the one never built. But when we do build, our materials are becoming significantly cleaner. Producers are investing in low-carbon processes and aligning with climate goals.
At Glotman Simpson, we work alongside our clients to track embodied carbon and support lower-carbon solutions. With improvements in material efficiency and cleaner supply chains, the future of concrete, steel, and timber buildings is much more promising than most people expect.
Written by Rory Roberts, P Eng
Together, we can contribute to a more sustainable built environment. If you are interested in sustainability and would like to discuss any of the topics in this article, please get in touch with us at [email protected].
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