The miraculous world of steel and the future of building design

constructsteel interviewed Ron Klemencic, CEO of Magnusson Klemencic Associates (MKA), following his keynote presentation, “The beautiful, amazing, miraculous world of steel.” A globally recognised leader in structural engineering, Klemencic is known for his work on some of the most ambitious and technically complex buildings around the world. In this conversation, he reflects on the role of steel in transforming modern architecture and construction.

During his keynote, Klemencic presented three projects that illustrate the capabilities of steel in pushing the boundaries of innovation and efficiency:

  • The Amazon Spheres in Seattle, a biophilic workplace made possible by complex yet modular steel geometry;
  • The Rainier Square Tower, which introduced the SpeedCore system for rapid high-rise construction;
  • And FastFloor, an emerging solution that aims to eliminate the need for concrete floors entirely, accelerating construction timelines even further.

What makes steel such an inspiring material for you?

Steel’s potential is extraordinary. It is strong, precise, and comparatively lightweight, yet highly adaptable in form. We have realised designs with steel that would be extremely difficult or inefficient with other materials — not only in terms of structural performance but also in delivering elegance and speed. Combined with digital design and prefabrication, steel allows a level of creativity and control that is unmatched.

Let us begin with the Amazon Spheres. What role did steel play in realising this concept?

The Spheres demonstrate how steel can enable bold architectural visions. Jeff Bezos challenged the design team to create a nature-filled space for Amazon employees — one that could house 40,000 plants in a setting that fosters creativity. The solution was three intersecting steel and glass spheres, based on a Catalan geometric solid. Despite their visual complexity, we completed the entire design using only 12 structural drawings. This precision, modularity, and efficiency simply would not have been feasible with concrete.

You referred to a component in the structure as the “Jedi Fighter.” Could you elaborate?

Certainly. The “Jedi Fighter” was the nickname given to the steel component used to stabilise the large pentagonal frames within each sphere. Developed through parametric design in collaboration with fabricators and architects, this infill piece balanced structural efficiency, aesthetic appeal, and ease of manufacture. It is an excellent example of how digital tools and steel fabrication work hand-in-hand to enable innovative forms.

Moving on to Rainier Square, this project introduced the SpeedCore system. What sets this approach apart?

SpeedCore is a prefabricated composite wall system comprising steel plates filled with concrete. It replaces traditional reinforced concrete cores in high-rise buildings, drastically reducing construction time. On Rainier Square, this system allowed us to complete the tower in 22 months — 10 months ahead of the original schedule. The implications for cost, logistics, and carbon emissions are substantial, and it’s a direct result of steel’s adaptability in prefabrication and erection.

Were there any challenges in implementing SpeedCore?

As with any new system, there was a learning curve. We conducted full-scale mock-ups to refine the details, particularly around field splicing and weldability. One key lesson was that while robotic welding is highly efficient in a factory setting, it is less reliable in the field due to environmental conditions and tolerance issues. That said, the overall process was remarkably smooth, and SpeedCore is now being adopted globally.

Your third concept, FastFloor, is still in development. What does it aim to solve?

FastFloor addresses the remaining bottleneck in steel construction: concrete floor installation. Even with SpeedCore, traditional decking, stud welding, and concrete placement slow things down. FastFloor is a prefabricated steel-based floor system designed to eliminate wet trades entirely. Initial lab results indicate we could save another 30% in construction time. Again, this is only feasible because of steel’s strength, modularity, and fabrication potential.

How does steel factor into efforts to reduce environmental impact?

Life cycle analysis tools still have gaps — particularly on the concrete side — but qualitatively, steel offers several advantages. It enables thinner walls, faster construction, and less rework. Steel is also highly recyclable, and low-carbon steel production is becoming more widespread. When speed, waste reduction, and precision are considered, steel has a strong case from both an economic and environmental perspective.

Looking ahead, how do you see steel evolving in the construction industry?

We are entering a new era of construction. Digital design, AI, automation, and modular techniques are converging — and steel is at the centre of that transformation. It is consistent, scalable, and well-suited to modern manufacturing methods. I believe steel will continue to drive innovation in both form and function, particularly for projects where time, complexity, and performance are critical.