We have a material problem! Packaging, consumer goods, personal electronics, durable goods, as well as buildings and infrastructure are all produced in a linear economy dependent on taking raw materials, manufacturing them into useful items, and then disposing of them at the end of their lives. While this linear process is sometimes interrupted by reuse (clothing resale, salvaged materials) and recycling, even these are just scenic routes on the cradle-to-grave trip to the landfill.
This take-make-waste linear economy is responsible for greenhouse gas emissions causing global warming, depletion of natural resources, destruction of habitat, mountains of waste, and pollution of air, water, and soil. Even after decades of recycling education, promotion, and infrastructure development, only about 35 percent of waste in the U.S. is recycled (32 percent globally), much of this is downcycled into lower valued products that cannot be recycled again, eventually ending up in landfills. Building materials account for 25 percent of the waste stream in the U.S. and only about 25 percent of construction and demolition waste (excluding concrete and asphalt) is recycled. Even before materials are installed in buildings, significant waste is generated in the extraction of raw materials and manufacturing of finished products.
We can do better! Nature provides some inspiration. There is no such thing as waste in nature as the residuals from one process become the feedstock for the next, eventually becoming nutrients to start the cycle over again. Unlike our traditional heat, beat, and treat industrial process that requires large inputs of energy, pressure and toxic substances, nature makes incredibly strong and complex materials in ambient atmospheric conditions with no harmful additives. For example, a spider’s web is once-for-once stronger than steel but is produced inside a spider’s body at around 31 C (88 F) compared to an electric arc furnace at 1,760 C (3,200 F). Creating materials inspired by nature is called biomimicry, a term popularized by Janine Benus in her 1997 book of the same name.
The answer to our material problem is a transition to a circular economy through the application of biomimetic design and other principles of circularity. We can better understand what is meant by a circular economy by contrasting it with a linear economy:
- A circular economy runs on renewable energy rather than fossil fuels.
- A linear economy generates waste, while circularity creates new resources.
- Circularity builds healthy soil, rather than depleting and contaminating it.
- Linearity is obsessed with efficiently making things, while circularity is focused on effectively remaking things.
This is easier said than done as we are not going to reverse several centuries of industrial momentum overnight. Complex supply chains need to be reconfigured with new infrastructure to close the loops, and research and development will be required to reformulate and reimagine the products we make. Circularity is a journey that will require creativity and collaboration between the many stakeholders in the material lifecycle, but the benefits will include reduced cost and risk and greater customer satisfaction. Increasing regulations for greenhouse gas emission reduction, embodied carbon limits and extended producer responsibility mean early innovators in circularity will gain competitive advantage. How do we start on this journey?
For material manufacturers, this includes transitioning to renewable energy (wind, solar, renewable hydrogen), redesigning products to increase the potential for disassembly and recycling and finding alternatives to toxic constituents that create hazards and hinder remanufacturing. Identifying and fostering relationships with partners who can help create a material recovery and reuse ecosystem is also critical. Reframing the value offered to customers creates opportunity, using a product-as-service approach to sell the utility they are seeking rather than products for which they become responsible for maintenance and later disposal.
For architects, engineers, and designers, there are many steps that can be taken to support the transition from a linear to a circular building industry. Some of these are articulated in the Circular Buildings Toolkit1 developed and released earlier this year by Arup and the Ellen MacArthur Foundation.2 Fundamentally, buildings should be designed to maintain long-term value, including increasing use of the building, and designing it for longevity and adaptability over time, and for eventual disassembly at the end of its useful life. Stewart Brand provided critical insight on how to do this in his 1994 book, How Buildings Learn: What Happens After They’re Built, that are highly relevant to circular building design.
Since even the most creative of architects cannot imagine the range of potential uses a building may serve 30 or 50 years in the future, making them adaptable allows the building to evolve over time. Additionally, since elements of exterior enclosure will be replaced several times, and the interior finishes many more, the initial design should accommodate the removal and replacement of these elements with limited waste, supporting the recovery and recycling of used materials. This also allows for the efficient deconstruction of the building at the end of its life. Circularity advocates are encouraging architects and contractors to create a material passport or disassembly manual for the building. This would inform future owners of the composition of materials installed in the building, assisting in determining the value and potential recyclability. It would also guide contractors in how to remove components for replacement or to deconstruct the entire structure.
We have a material problem, but circularity provides a roadmap for the journey toward the emerging solutions that will reduce the negative impacts from extraction, manufacturing, and disposal we currently experience. Awareness of the issues, collaboration between the multiple stakeholders in material supply chains, innovation in product manufacturing and remanufacturing, thoughtful design and construction processes, and development of new repair, replacement, and deconstruction practices will all be required to transition to a circular building economy.
Notes
1www.arup.com/services/climate-and-sustainability-services/circular-economy-services/circular-buildings-toolkit
2 www.ellenmacarthurfoundation.org/
Alan Scott, FAIA, LEED Fellow, LEED AP BD+C, O+M, WELL AP, CEM, is an architect and consultant with more than 35 years of experience in sustainable building design. He is director of sustainability with Intertek Building Science Solutions in Portland, Ore. To learn more, follow Scott on LinkedIn at www.linkedin.com/in/alanscottfaia/.