Most engineers have a story about playing with LEGOs growing up and how it helped shape their interest in building things and creating. This statement is true for me, but I also learned some lessons later in life.
Walking through a LEGO store recently reminded me of how different LEGOs are now compared to when I was a kid. The things you can create now out of the box can be amazingly detailed and intriguing. Now, you can buy the Eiffel Tower, a Bonsai tree, the Concorde passenger jet, or even Hogwarts. There is something special about the unboxing and the process of constructing piece by piece to see it all come together. If you have kids, inevitably, you've experienced heartbreak as the masterpiece is deconstructed and reassembled into a Frankenstein monster. All that hard work and time investment - gone. Although, the second or third life can be equally interesting; a Star Wars spacecraft mixed with the Batmobile, for example.
The incredible thing about LEGOs is that the parts are interchangeable, and there's no change to their form and function when reused. When can we build actual buildings that way? Building demolition creates a significant portion of our construction waste, with little material able to be reused. Additionally, even more energy and materials are needed to replace an old building with a new one, no matter how sustainable or "green" the design is. Construction today has many single-use parts that have one function and one use.
At best, some portions of building parts can be recycled, like structural steel and potentially concrete rubble as base rock or construction fill. Most of the demolished construction is essentially waste. San Francisco, for example, has a zero waste target for construction and a current ordinance to reduce debris sent to landfill or incineration by 50% by 2030. https://sfenvironment.org/sites/default/files/fliers/files/ordinance_no._144-21_cnd_update_9.24.2021.pdf
However, changing construction debris back into useful materials can be energy-intensive. This type of recycling is considered a down-cycle. LEGOs have no downcycle, or upcycle, for that matter, but can be reused indefinitely. Forever a footstep away from a sharp pain in your foot.
Rethinking the way we design and construct buildings is underway. No, I'm not suggesting buildings made of LEGOs, which has proven to be a building that nobody wants.
Instead, an initial step for improving building design is to consider our material choices and how we design buildings to go together and come apart, thus Designing for Deconstruction. Chemical adhesives, embedded parts, weldments, and binders connect building parts but are not designed to come apart - by design. Creating a deconstruction potential for a component requires a mind shift. Good design is bringing pieces together as well as being able to remove and separate them when the time comes for reuse. Further, the parts should be configured so that reuse is possible as a building block for future construction, enabling a higher component reuse potential.
For the first time, we are adding Deconstruction Drawings to our plans that show the builder... err.. deconstructor? how our buildings can come apart for reuse of components. A mandate to reduce construction waste is an early step in San Francisco, which can only be successful if we, as designers, also do our part. Designing our buildings for parts reuse is a better step towards a future where our construction components have an equal or greater value after the first use. Thanks LEGO.
GB
I highly recommend "The Upcycle - Beyond Sustainability, Designing for Abundance" by William McDonough and Willing Braungart for further reading on creating a sustainable footprint within our reach.
