Innovation in structural engineering rarely comes from a single breakthrough – more so it is about building on ideas and connecting them in new ways. In our previous post, we explored how modern damping devices allow us to design more efficient structures, but what if there were an even smarter way to tame wind and earthquakes, one that goes beyond the conventional design playbook? This post introduces the next step in that evolution: Performance-Based Design (PBD). This approach allows us to see exactly how a building will behave under real conditions, while unlocking the full potential of the damping technologies we explored before.

Moving Past Prescriptive Limits

PBD changes the conversation entirely. Instead of following prescriptive rules, engineers can now model the building’s behaviour with remarkable precision – it is like moving from a black-and-white sketch to a full 3D animation. Engineers can see where forces concentrate, how the structure flexes, and where strength and ductility are truly needed. The benefits are immediate: resilience improves while achieving leaner structures. The challenge is that PBD is highly technical, requiring specialized expertise, and demands careful calibration. After decades of previous projects and learning opportunities, Glotman Simpson has applied these approaches across hundreds of projects, giving us the experience to navigate this complex approach and explore its full potential.

Seismic Design with Real-World Inputs

Performance-Based Seismic Design (PBSD) is where the story begins. Instead of relying on prescriptive and general code recommendations, PBSD allows engineers to simulate how a building responds to real historical earthquakes, show how energy flows, and how to protect occupants while avoiding unnecessary material. It is a smarter, more intentional approach that often reveals opportunities to reduce seismic forces without compromising safety. At the same time, North American codes now permit further reductions of seismic demands by incorporating damping devices. Consider the building from our earlier post where we introduced Viscous Coupling Dampers (VCDs) primarily to control wind vibrations and ensure exceptional comfort for occupants. If that same building is evaluated through the lens of a PBSD framework, those same devices could have contributed directly to seismic performance, reducing earthquake forces by roughly 8% simply by letting the dampers already in the building do more of the work. That reduction would have cascaded into thinner walls and lighter foundations.

Wind Performance, Reimagined

But why stop there? Tall, slender towers have long been shaped by simplified prescriptive wind loads, often leading to heavier than necessary structures. Performance-Based Wind Design (PBWD) turns that approach upside down. By combining wind-tunnel data with detailed nonlinear analysis, engineers can understand exactly how a building moves under real windstorm conditions based on historical data. This insight allows us to maximize the balance between stiffness, mass and strength, ensuring comfort for occupants without overbuilding.

The true power emerges when these approaches are combined. In an internal study of one of our recent projects in Burnaby, BC – Gilmore Place Tower 2, a 67-storey tower and currently the tallest building in British Columbia – where we compared the results of PBSD and PBWD against traditional code-based design. The tower was evaluated using 11 earthquake ground-motion records and eight sets of windstorm histories specific to Burnaby. When the building was tested under these realistic hazard inputs, the opportunities for efficiency became unmistakable. We found that the reinforcement in the lateral system could be reduced by roughly 20%, representing 1 million pounds of steel. And while this study focused on the shear walls only, similar reductions would have cascaded down into the foundation system as well, further amplifying the material and carbon savings.

With state-of-the-art tools and innovative engineering, buildings can rise higher while leaving a lighter footprint. Taller is no longer synonymous with heavier, costlier, or carbon-intensive. Our goal is simple: to meet the client’s boldest aspiration, turn the sketch into reality, and simultaneously design greener, more efficient structures by pushing the limits of the tools available. It is a win-win scenario. Clients get the best possible outcome, and we get to embrace the challenges that drive innovation.

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].

For more information on our sustainability initiatives and to stay updated on our latest projects, visit our website and follow our “OnTrack” blog series.

Written by Miguelangel Bilotta, Structural Designer