As engineers, we love to be efficient. When evaluating historic building structures, it is interesting to see how structural engineers historically highly optimized the materials in their designs. Old “blueprints” from the early 1900’s through the 50’s and 60’s are surprising for young engineers to observe how many different beams, columns, and slab types occur in one building. Some buildings can have over a hundred types of beams that vary in depth, width, and reinforcement, all on one floor. Nowadays, there are fewer unique, building structural components, but why?
Many decades ago, materials like concrete and steel reinforcement were costly and labor was cheap; compare that to now, where labor cost drives most of our engineering decisions. Often, new concrete building designs, for example, have repetition in components to reduce formwork costs for beams, columns, and slabs. But what does that mean for the overuse of materials and sustainability?
As an industry, there is a focus is on minimizing labor costs and reducing schedule over the “price” of material. The drive for more sustainable designs is shifting this paradigm, and optimizing structure for both material AND labor can be complex, especially when quality and customization drive owner expectations. Prefabrication and Modular Construction does seem to be one way to balance these essential characteristics by replicating a manufacturing process of skilled labor in a factory setting to maximize quality, using engineering optimization to fine-tune repetitive parts, and using digital technologies to manipulate features to achieve design customization.
We are now optimizing structures to reduce the carbon footprint, but the future may mandated limits on materials and emissions for environmental sustainability. The building designers of yesteryear would think everything old is new again, where structures are optimized to be material efficient. Still, the new compounding factor now is that labor efficiency is also required. It’s exciting to see how sustainability is changing everything we know about how to build.
