Steel’s sustainability story is evolving—from recycled content and efficiency to cutting-edge advances in metallurgy, chemistry and engineering that deliver stronger, low-carbon steel and enable smarter reuse in modern construction.
In the small town where I live, new owners are making an old store on the courthouse square into a restaurant. I remember that store from when I was a child, with aromas ranging from insecticides to fresh vegetables, and all-brick load-bearing construction supporting old-growth wood roof rafters.
The local historic preservation group has mandated the brick façade and side wall painted with a mural to be preserved, and the owners have gotten permission to add a second story with a rooftop patio: including expansive views of the old courthouse surrounded by ancient oaks and the old town square.
The sad part about all this is the way the new structural engineer is approaching the project: using a massive structural steel moment frame to support everything, not using much of the existing structure or materials for anything other than outward appearance.
Fortunately, this is not the norm. Most structural engineers and owners today realize the value of adaptive reuse: for both cost and environmental purposes. And steel framing plays a major role in this new narrative: for both new and reused structures. New thinking is required to ensure a sustainable future for construction: not only in the design using less materials, but in the production of those materials in the first place. This article chronicles several of the advances in the steel framing industry and how those advances translate into reduced environmental impacts for buildings.
Wall and ceiling commercial contractors have a lot of experience with adapting old buildings to new uses: and have had to deal with the remediation issues that come with old buildings. From mold and rot to termite damage and lead paint, renovators get to see firsthand how materials stand the test of time.
Most building components including concrete, steel, wood and masonry perform well if they are properly maintained, protected, and kept from persistent moisture. Thankfully, steel framing is not susceptible to insect or fire damage and will not mold or rot. And because of modern tools and new materials, it is easier than ever to make curved surfaces from steel: not only walls and ceilings, but soffits, openings, decorative columns, towers and fins, all framed with thin steel.
The good news is that because of the high strength-to-weight ratio of steel, less material is required to provide the same strength and support. When older buildings want to add space, cold-formed steel (CFS) is often the answer: stacking one or two stories above an existing structure has been done without foundation upgrades, and minimal increases in the gravity and lateral load systems in most areas of the country. This ability to augment and reuse structures has a huge impact on the carbon emissions of a construction project.
In 2023, the Environmental Protection Agency (EPA) announced they would be awarding grants for “Reducing Embodied Greenhouse Gas Emissions for Construction Materials and Products.” This funding had three objectives:
Increase the robustness of greenhouse gas emissions data associated with the production, use and disposal of construction materials and products;
Assist businesses in disclosing and verifying these data via robust environmental product declarations (EPDs), and supporting municipalities and non-profit organizations that assist these businesses; and
Spur market demand for construction materials and products that have lower embodied greenhouse gas emissions.
The steel industry, along with the concrete, wood, masonry and even exterior insulation and finish systems (EIFS) industries, applied for these grants totaling more than $160 million. In 2024, the awards were announced, and the steel industry grant was approved for more than $6.3 million.
Unfortunately, after the 2024 elections, the status of these grants became unclear. Initially, these grants were listed as cancelled, then a few months later they were removed from the cancelled list. As of this writing, it is not clear if this funding will be available, but even without it, the steel industry is moving forward with new programs for a more sustainable future.
As of spring 2025, the latest version of updated steel-framing product completion reports (PCRs) completed their public review process and were published as final. This means that individual companies and associations can begin the process of updating their environmental product declarations (EPDs) to these newly revised rules. Although the updated PCRs and EPDs will not benefit from the stalled EPA grant program, they show that the steel industry is moving forward with continuous improvement on both processes and transparency.
The Steel Framing Industry Association (SFIA) is currently working with its members to recruit participants for the industry-wide EPD, and individual EPDs for specific manufacturers and manufacturing facilities. In addition, researchers have developed some materials and processes that will change steelmaking forever. Here are some of the most promising ones.
Advanced High-Strength Steel (AHSS)
Originally developed for the automotive industry to compete with aluminum for structural elements of cars and trucks, AHSS has potential for use in cold-formed steel (CFS) framing for buildings.
Most framing products currently available for commercial use have a design yield strength of 50 kips per square inch (KSI) or less. There are systems originally developed in Australia and New Zealand that builders are now using in North America that have 70 and even 80 KSI steel.
The AHSS used in automotive has a potential for even higher capacities: well above the 80 KSI being used on some structures. This has the potential not only for reducing the weight of structures but increasing the height where steel framing can economically be used on mid- and high-rise structures and reducing the carbon footprint of CFS framed structures.
Manufacturers have already taken advantage of higher yield steels in nonstructural applications through the development of equivalent (EQ) studs: these products have reduced the weight and carbon intensity of nonstructural applications by an average of 30%. Even higher reductions are possible in structural applications using derivatives of AHSS products.
Eliminating the Blast Furnace
The two biggest sources of greenhouse gas (GHG) emissions in steelmaking come from the production of electricity to power the process, and the blast furnace that removes iron from iron ore. The blast furnace takes iron-rich minerals that are mined, and by heating these minerals in the presence of carbon, separates the iron and oxygen. The oxygen binds with carbon, producing CO2, which is released into the atmosphere. There are two promising technologies that have already changed the way this is done at smaller scale: the plan is to scale this up to production levels.
The first of these technologies is a special form of direct reduced iron, or DRI. Direct reduction uses lower temperatures than the blast furnace and combines heated iron ore pellets with heated gas: either carbon monoxide or hydrogen. When the process uses hydrogen, there is no CO2 emitted, and the reduced iron that comes from this process can go directly into an electric arc furnace, further reducing the carbon emissions that are associated with the basic oxygen furnace.
A proprietary version of this process is called hydrogen breakthrough ironmaking technology (HYBRIT); the first HYBRIT facility opened in Sweden in 2021 and has been making steel for their automotive industry ever since. HYBRIT replaces the blast furnace, and also replaces the carbon-rich version of coal (known as coke) that is used to remove the oxygen from iron. By using hydrogen, the “waste” product is H2O instead of CO2—so this plant’s waste is water instead of greenhouse gasses.
The second of these technologies is molten oxide electrolysis (MOE). MOE has been used for over 100 years to process other metals such as aluminum, magnesium, lithium and sodium. By passing electricity through an electrolytic solution, pure iron can be processed directly from iron ore. The iron ore is added to an electric cell that has a carbon-free anode submerged in the electrolytic solution, then the entire assembly is heated to more than 1600 degrees.
At this temperature, the iron and oxygen separate, with no emissions other than pure oxygen gas. The molten iron, which is heavier than the electrolyte, pools at the bottom of the cell, and is tapped and removed for eventual steel-making. A company out of Massachusetts called Boston Metal has pioneered this technology with steel and has recently completed a manufacturing facility in Brazil.
All steel-making processes require a lot of electricity, and the DRI process requires green hydrogen to be truly carbon neutral. The other requirement for green steel is a green energy grid: providing both electricity and hydrogen at scale in a carbon-neutral way.
Conclusion
Although none of these technologies will help the almost complete steel-framed renovation in my hometown, I am optimistic that future structures will have reduced environmental impact.
Organizations like the SFIA will continue to work to educate users on efficient use of steel framing, and groups like the Cold-Formed Steel Engineers Institute (CFSEI) will educate engineers and architects on efficient design principles.
If you run into designers or building officials that have concerns about the sustainability of steel framing, link them to SFIA and CFSEI for resources and technical expertise that can help guide their decisions. CD
Don Allen, PE, SE, LEED AP, is the executive director for the Steel Framing Industry Association.
