With the conclusion of the 26th United Nations Climate Change Conference of Parties in Glasgow last week, the world’s supply chain remains in turmoil. Unprecedented bottlenecks at ports are causing material shortages, construction delays, rising costs, and other harmful disruptions across industries. But in this moment of chaos and climate crisis, we also find an opportunity to redefine the building sector. By shifting our focus to sustainable building materials and products, we can make a profound difference in decreasing carbon emissions, improving the resilience of global supply chains, and bringing about a more sustainable future.
Each country and every sector has a part to play in taking climate action. The building sector, in particular, has the chance now, today, to take a leadership role and swiftly start enacting positive change. Buildings generate some 40% of all emissions each year, with embodied carbon—that is, CO2 released through the harvesting, manufacture, and transportation of raw materials used in construction—accounting for around 11% of total emissions annually. That proportion is growing as building operations become more efficient, and by 2050, embodied carbon could come to represent half of all building-related emissions.
By focusing our energies on reducing the embodied carbon of the built environment, we have the opportunity to make an enormous, lasting impact on the health of our world.
Better Building Materials
Where to begin? The materials that make up the structure of a building are some of the greatest offenders. Cement, a component of concrete, accounts for nearly 10% of worldwide emissions. Steel, widely used in building structures, is nearly as carbon-intensive. But other materials with relatively low embodied energy are also available. The carbon footprint of timber, for example, is as much as five times less than steel.
Cutting-edge design strategies now allow for the use of less of these high emissions materials; to make the traditional structural materials we do use to be more carbon-friendly; to source materials locally, streamlining transportation and easing supply chain congestion; and to use alternative materials in a way that adds both aesthetic and market value to projects.
One example of this strategy is the use of mass timber. This robust building material is made by gluing pieces of timber together to form thick structural elements such as cross-laminated timber panels. Like concrete, the material is fire resistant, but it has much lower embodied energy, given that wood sequesters vast amounts of carbon. Mass timber elements can also be installed quickly on-site, with added benefits like reduced construction time, traffic, and noise, along with minimal waste.
In Bentonville, Ark., Gensler’s design for Walmart’s new 350-acre campus exemplifies the potential of this material. The project will use more than 1.7 million cubic feet of Arkansas-grown and Arkansas-produced mass timber across more than 2.4 million square feet of office space, making it the largest mass timber corporate campus currently under construction in the United States. With ambitious sustainability goals—efforts prioritize people and the planet by aiming to source responsibly, eliminate waste and emissions, sell sustainable products, and protect and restore nature—the design approach will create a winning and inspirational work environment that promotes a healthy mind and body for associates, enabling Walmart to continue attracting top talent as it looks toward the future.
Another example is 3855 Watseka, an urban infill site in downtown Culver City, Calif. With a striking sawtooth roof that draws sunlight and natural ventilation deep into the building, the project will be the first in Culver City to use CLT wood framing on the top floor of an office. This design move not only improves user experience and elevates the building’s aesthetic value; it means the building requires less steel and concrete, lowering its overall carbon footprint.
Healthier Finishes and Furnishings
Another opportunity to reduce emissions is found inside buildings. While structural materials have the biggest initial impact on embodied carbon, the interior elements, which are often replaced every few years, can quickly add up. This repeated churn of materials over the life span of a project can ultimately result in an equal or greater share of the whole-life carbon footprint than the structural materials.
To rectify this cycle, designers need to consider the materiality and afterlife of furniture and interior finishes. What is a product made from? How much space will it take up during shipping or transport? Can it be easily disassembled and recycled once its service is complete? Or can it be reused or repurposed? Environmental product declarations—reports that summarize a product’s environmental information—are one useful tool for making smart design choices.
This future-focused approach to product design guided Gensler’s development of the Mixu seating collection for furniture brand Arper. Originally tapped to design a new plastic chair, our team leveraged the knowledge and experience of Gensler’s design directors around the world, learning that what designers and clients most want in furnishings is the ability to customize. The three-part chair meets that need while also achieving sustainability goals through “design for disassembly.” Discrete components—seat, backrest, and base—use post-industrial recycled plastic, 100% recyclable plastics, recycled steel, and FSC-certified wood. Upholstery can be zipped off and changed out, extending its use. And, there are no adhesives, staples, or co-molding of plastic and metal, allowing for full disassembly—useful both in transit (smaller boxes mean a lower environmental footprint for shipping) and at the end of the chair’s life, when components can be recycled.
The Road Ahead
Looking toward a more resilient future for the entire supply chain of building materials, Gensler is taking the lead with a green materials initiative that focuses on reducing high-carbon materials, using the most efficient structural solutions to reduce material quantities, sourcing materials that are extracted and manufactured locally, and minimizing waste. After we launch this effort in early 2022, we will prioritize working with partners—from engineers and contractors, to engineers, general contractors, and beyond—who meet these standards and use materials that significantly reduce construction-related emissions. Not only will this initiative help to ensure that our clients’ properties meet new sustainability mandates, building codes, tenant demands, and health requirements, this change in demand for sustainable materials will have a powerful, lasting ripple effect across the building sector and the supply chain—and across our world.
The views and conclusions from this author are not necessarily those of ARCHITECT magazine or of The American Institute of Architects.
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