As the steel sector searches for sustainable solutions in the carbon heavy construction industry, it is crucial not to overlook the power of conservation and efficiency. Decisions made early in the design process, using quality data, have a major impact on a building’s carbon footprint. In fact, when we use early data to our advantage, steel becomes a much more sustainable building material.
It’s valuable to remember that most building materials increase atmospheric carbon in one way or another. Cutting trees releases carbon from the forest floor. Fewer trees also means less carbon dioxide is absorbed from the atmosphere, and ecosystems are often disturbed. Producing cement involves heating limestone (calcium carbonate) to high temperatures, releasing CO2 as a byproduct. In fact cement is responsible for 60-90% of concrete’s GHG emissions depending on the mixture and location. (Sabbie A. Miller et al, 2021) Concrete also extracts raw materials, leading to a depletion of natural resources.
Opting for greener, lighter, higher strength steel can significantly enhance a project’s level of sustainability. And while companies like Nucor invest in greener energy to produce steel more sustainably, we can all make a difference today. Although greener electricity will certainly make steel greener, the easiest way to turn steel into a more environmentally friendly option is to use it more efficiently.
The Art of Conserving Steel
Quality is paramount:
Structural integrity and safety cannot be compromised. However, we can reduce the carbon footprint of a building by as much as 15% or more without sacrificing quality or safety. In fact, IStructE’s recent book states that steel building elements have excess material beyond the building code requirements by as much as 50% (Design to Zero, 2022).
Reducing Waste overall:
We must remember that seemingly small actions can have a monumental impact. Every pound of steel saved is a small step toward increasing the sustainability of structural steel. By optimizing where possible and practicing the best construction delivery methods like Early Connected Models, we can significantly cut down on steel waste (and time and money and carbon).
Each inch of weld represents energy expenditure. Utilizing advanced welding techniques and steel grades such as AEOS grade A913 which doesn’t require preheating for welding not only enhances structural integrity but also reduces the overall carbon footprint of the project.
Precision Bolt and Nut Usage:
Bolts, nuts, and washers may seem small in isolation, but their cumulative weight and impact can be substantial. For example, some research says that the fabrication drilling process can have a 7 fold impact on carbon emissions vs welding (Suban et al, 2012). By designing and engineering with precise early data, you can ensure that each fastener satisfies the integrity and safety of the project without unnecessary excess.
Optimizing Steel Connection Material:
Steel connection materials like angles and plates can be a large contributor to connection complexity based on how efficiently connections are designed. Employing cutting-edge software for the careful design and preparation of efficient connections enables engineers to optimize for the least amount of steel fitting materials relative to framing. Consider for a minute the significance of saving each inch of steel beam, every bolt, nut, washer, inch of weld, and pound of steel plate…it adds up. For example using extended shear plate connection types can not only reduce framing member lengths but speed up erection, reducing carbon usage on the jobsite.
The energy-intensive process involved in steel production requires substantial amounts of fossil fuels. By optimizing steel usage, we indirectly reduce the demand for these energy-intensive processes, promoting a more energy-efficient industry. Processing mill orders of the exact length of materials (versus the centerline dimensions without setbacks) can result in excess steel being ordered that has to be recycled back to the mill. For steel buildings with bracing, this can result in 5 to 10% additional steel being ordered.*
Steel production has a large carbon footprint – it is responsible for 7% of carbon release worldwide1. In the quest for a more sustainable future, the structural steel industry has a vital role to play. By recognizing the importance of saving every ounce of steel, bolt, nut, washer, inch of weld, and pound of plate, we can enhance the carbon efficiency of steel and reduce our collective carbon footprint. Every bolt counts. As we forge ahead, let’s embrace the power of conservation and efficiency and contribute to a forward-thinking culture of sustainability. This goal becomes easier to achieve with new technology and new processes, and Qnect is committed to playing its part in building a world that not only stands strong with the many attributes of steel, but stands sustainably too. The ripple effect from seemingly inconsequential decisions like saving bolts, inches of weld or pounds of plate will influence industry standards and lead the market to adopt greener construction practices on a worldwide scale.
- IEA (2020), Iron and Steel Technology Roadmap, IEA, Paris https://www.iea.org/reports/iron-and-steel-technology-roadmap, License: CC BY 4.0
*Cumulative Qnect project metrics