How long does a brick last? Where do the materials to manufacture a window come from? Can solar panels be reused? When we talk about ‘sustainable cities,’ we typically focus on strategies for ensuring energy efficient buildings, tactics such as optimal building orientation, or even solar panels. But there is a fundamental step prior to this stage: Are the building materials we use sustainable?
Swiss architect, Walter R. Stahel, coined the term ‘Cradle to cradle’ in the 1970s to refer to a new approach to sustainability. It refers to using goods and materials that are durable over time, that are not thrown away when they are no long in use, but are rather returned “to the cradle,” meaning that they can be entirely re-used for something else once they are finished with what they were originally designed for. The term was re-embraced and popularized by the authors, William McDonough and Michael Braungart in their book ‘Cradle to Cradle: Remaking the Way We Make Things‘ (2003) where they address the need to rethink how products are designed. They advocate for optimizing products by starting at the source: optimizing the components that constitute the product.
Three spheres of sustainability
To better understand the factors that are involved in studying the sustainability of materials, one must first focus on the concept of the ‘triple bottom line,’ which refers to the three areas an organization must take into account when assessing its activity: the social, the economic, and the environmental. These three areas should be addressed in tandem with equal priority because if one of them suffers from any significant deficiency, it will be difficult to ensure the others operate smoothly.
Applying this system to the construction business, the materials that are used should not only be high-quality and durable, they should also have been sourced responsibly, respecting the three spheres of sustainability. What this means, practically speaking, is that they should be produced locally, to benefit the local economy, and they should be manufactured under decent working conditions, an important social factor. Furthermore, once the product’s service life comes to an end, it should not litter the landfill for years to come, rather it should be able to decompose, returning to the earth, and thus aligning with the third sphere of sustainability, the environment. If this is not possible, components or materials should at least be able to be wholly reused with high quality standards for new products.
The limits of eco-efficiency
“Today’s industrial infrastructure is designed to chase economic growth. It does so at the expense of other vital concerns, particularly human and ecological health, cultural and natural richness, and even enjoyment and delight,” McDonough and Braungart claim in their book, and they challenge some of the measures that are frequently considered to be the solution to sustainability problems, such as ‘eco-efficiency‘’or ‘the Rs‘.
Eco-efficiency, a term coined by the World Business Council for Sustainable Development in 1992, refers to the ratio of the value of the product or service produced (the output) divided by the total environmental cost to produce it (the input). Since then, many corporations have embraced eco-efficiency as their banner and its application in practice: ‘reduce, reuse, and recycle.’ The time has come to ask if these ‘3 Rs’ are sufficient. Reducing is not enough when resources are limited, because it merely puts off the inevitable point of total depletion, rather than eliminating this deadly fate. The reuse of residual materials could seem like a solution, but many of these materials contain harmful substances that can make jerry-rigging them for a new purpose dangerous. Finally, recycling today neither has the capacity to restore all types of materials nor is it of the best quality when it can be done. All these reasons add up to the fact the eco-efficiency, while a nobly-motivated goal, has fallen short of tackling the climate crisis in which we find ourselves.
A roadmap towards eco-effectiveness
McDonough and Braungart conclude that we have to go even further than eco-efficiency, introducing what they call ‘eco-effectiveness’, by which they mean a total reexamination of production from its very nature and its most basic procedures. They establish five steps that designers and architects need to consider when it comes time to manufacture:
- During the manufacturing process start at the most basic and, to the extent possible, avoid the use of harmful substances or materials that contain them, such as PVC, cadmium, lead, or mercury.
- Choose materials that have been manufactured in the most responsible way possible, according to each of the spheres of sustainability. Specifically, using materials that are manufactured in a way that respects the workers who produce them, the communities where they are produced, the people who transport them, and the customers who consume them.
- Having addressed the first two steps, classify the manufacturing materials into three relatively accurate lists: the X list for the most problematic substances; for example, those that can release toxic substances during production; the gray list, which will contain substances that are problematic but whose elimination is not as urgent or might not even be possible because there are no alternatives; and the P list — p for ‘positive — which will ultimately contain all the health-friendly and safe substances. In this third phase, the attempt should be made — without changing the production standards —to ensure that the last list is longer and longer compared to the first two lists. To use a cooking metaphor, up to this point, we have been choosing the best (the healthiest and most responsibly sourced) ingredients; but each step in the recipe has remained exactly the same.
- From this step on, we move from a“less bad” production approach to one that is “better,” meaning that we have moved from eco-efficiency to eco-effectiveness. First, it advocates for the increased use of products from the ‘P list’ — the positive materials — changing production standards as necessary in order to make room for the safest substances and exclude the most dangerous materials. To extend the cooking comparison, we would be making the same recipe but changing the steps, its instructions, and the cooking times, with the aim of expanding the list of ‘good’ ingredients.
- The final step is reinvention, which means to open the mind to new possibilities that could address people’s’ needs differently, but more sustainably. We change the recipe, making another one, which as a whole is much healthier but still addresses the fundamental need of providing nourishment.
To illustrate the steps above, let’s take automobile manufacturing as an example. For more sustainable design and production, materials with toxins (such as mercury switches, which some manufactures still produce) would have to be discarded outright. Next, the classification exercise would be undertaken, and all those materials that are classified as unhealthy or unsafe would be substituted with other materials. All this would happen without redefining the production process foundation. For example, paint that does not contain chrome would be used. Taking the next step would consist of changing the manufacturing process if doing so would increase the number of safe and reusable materials on the list. For example, when designing the car, taking into account how it would be disassembled when it reached the end of its service life, so that all the materials that went into making it could easily be separated and recycled. The greatest manifestation of eco-effectiveness would be to rethink how to satisfy human transportation needs in a more sustainable way; maybe cars are the most efficient solution. But, could there be another type of vehicle that is more environmentally-friendly?
Commenting on the sustainable design shortcomings going back to the Industrial Revolution, McDonough and Braungart maintain: “Poor design on such a scale reaches far beyond our own life span. It perpetuates what we call intergenerational remote tyranny — our tyranny over future generations through the effects of our actions today.” The sustainable building of the future begins with questioning the construction materials and techniques that have been used for more than two centuries. The task, while it may be Herculean, is one of the essential steps to change the future that will be left behind for generations to come.