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The most sustainable building material you’ve always known

The Most Sustainable Building Material You’ve Always Known

by MARK THIMONSPE, LEED AP, BDC | Nov 21, 2015

This week at Greenbuild 2015, if someone had announced a new building construction material that contains 25% to 100% recycled content, complies with existing construction codes, requires essentially no maintenance, can contribute to achieving several LEED v4 credits, is nontoxic and noncombustible, creates minimal waste during production, and is 100% reusable or recyclable at end-of-life, with no loss in capabilities, then, well, you’d definitely want to hear more.

Of course, you would then be surprised to learn that we already have that exact product. It’s steel. 


So today, as we discuss what our built world will look like in the future, we have to start with the material that’s formed the core of our society for the past century. The buildings, roads, bridges, energy grids, and other engineering works that we depend on as a society today all in turn depend on steel. That adds up.

Roughly a third of the steel in North America – and half of the steel produced worldwide – is used in construction. This means, however, that steel is so ubiquitous that even people who spend their days immersed in green building topics rarely stop to consider how well it demonstrates meaningful sustainability throughout its life cycle.

Even fewer are aware of the advances that North American steel producers have made in energy usage, resource efficiency, carbon emissions, waste reduction, recycling and more to continually make steel a more sustainable material. For example, since just 1990, the amount of energy needed to produce a ton of steel has decreased by 32% and the associated CO2 emissions by 37%, with more improvements on the way. For more, click through this fact-filled gallery below.

Fortunately, the maturing of a more complete, whole-building life cycle assessment framework for sustainability is helping architects, designers and builders make better product selection decisions. Research-based standards and programs are confirming this. For instance, while every project is different, steel can help to achieve a half dozen or more LEED v4 prerequisites and requirements in areas such as raw materials sourcing, disclosure and optimization, construction and demolition waste reduction, building life-cycle impact reduction, low-emitting materials, and even heat island reduction.

   Earlier this month, SMDI launched this new educational website just for construction,  

   Earlier this month, SMDI launched this new educational website just for construction,  

Steel is also critical for implementing a number of other concepts or technologies that are included in LEED v4 credits, from efficient site usage to renewable energy production, to indoor air quality and more. Its durability also creates opportunities for sustainability stretched over generations. The materials choices of builders of prior eras come into play as we extend how we look at rebooting structural life cycles, as buildings constructed with steel are most likely to have the “good bones” that underpin sustainable historic preservation and adaptive reuse.

With end-of-life beginning to factor into the design process, steel’s long-term durability, reliability and ease of maintenance give the designers and builders to come after us more to work with than any other material. So, today, as our society becomes more thoughtful about what, how and where we build, it’s a good time to take another look at steel, a truly sustainable building material.

A civil engineer based in Pittsburgh, the author is vice president of sustainability for the Steel Market Development Institute, and executive director of the Steel Recycling Institute. SMDI is a business unit of the American Iron and Steel Institute. He can be reached via e-mail at

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