Building Toward a Net Zero Future: The Critical Role Walls Play

Performance used to be easier to define when selecting a wall system for a new project. Nowadays performance includes reducing embodied carbon, design flexibility, circularity, and health and wellness, and they are playing bigger roles in the material decision-making process.

“In terms of how we build and what we build with, we can make better product decisions about the design of how buildings are put together and then deconstructed,” says Brent Trenga, LEED AP BD+C, WELL AP, and director of sustainability for Kingspan North America.

With 6.13 billion square meters of buildings constructed annually, accounting for 3.7 billion tons of embodied carbon emissions and 11% of global greenhouse gas (GHG) emissions, there are plenty of opportunities to make changes that have a large impact on the built environment and the health of the planet.

Reducing embodied carbon.

Finding ways to reduce operating emissions continues to be important, but there is a shift to also focusing on embodied carbon. The embodied carbon in new construction is expected to rise to almost 50% of a building's overall carbon footprint during the next three decades. By focusing on high volume materials and high emission materials, the biggest reductions to can be made to this amount. For industrial buildings, that means wall systems, since concrete, iron, and steel can account for about 9% of annual GHG emissions.

Reviewing life-cycle assessments (LCA) and Environmental Product Declarations (EPD) help guide selections to materials with lower environmental impacts. Plus, organizations like the Carbon Leadership Forum, Architecture 2030, and Building Transparency offer resources to help reduce embodied carbon in the built environment.

Circularity.

Considering what happens to the materials after deconstruction can be a major factor in life-cycle assessments and choosing building materials to meet net-zero goals. While many demo sites sort materials for recycling or reuse, more eco-friendly reuse and repurpose options are on their way.

“We're looking at this kind of lifecycle framework, which is a lean and circular design,” says Trenga. Kingspan’s QuadCore® insulated metal panels are attached with a tongue and grove system, which then attaches to the structure of the building with hidden or exposed fasteners. This allows the panels to be reused when it’s time to modify or deconstruct a building.

They also can be recycled. “We are working to refine technology that can chemically recycle the foam and insert that material back into our own supply chain,” says Trenga. Since steel is infinitely recyclable, it can be stripped and reused, too.

Health and Wellness.

Whether the top goal involves achieving net-zero, earning LEED credits, or maxing out square footage for rental potential, the insulation that is used in a wall system also can greatly impact the health and wellness of the people constructing and occupying it.

Wall systems like QuadCore® metal panels that have low VOC emissions and no Banned List or Red List chemicals are a great option when seeking building certifications from LEED, WELL, and Living Building Challenge. It’s worth noting that the old rule of thumb that reliable eco-options had to be more expensive is long gone. Many newer products may cost less, but be aware that if there is a learning curve for unfamiliar contractors those savings will be reduced. This is something to flush out in the bidding process to material selection.

“The narrative that green healthy materials are more expensive is not accurate,” says Trenga. “Designers have proven that high performance, healthy buildings can be delivered to clients within their standard budget range. Product selection, integrated design process, and our ability to leverage many of the software tools available in the market give us more advantages than ever to design better.”

Design Flexibility.

Organic materials may not always have the least environmental impact; they aren’t always practical when it comes to performance metrics like R-value and wall thickness. High-performing thinner wall assemblies that are made at renewable energy-powered factories with high recycled content provide decreased carbon impacts with the benefits of design flexibility.

Wall systems with PUR and PIR can offer these benefits with better thermal performance, and a proprietary hybrid PIR called QuadCore offers even more with 11% better R-value than PIR and 60% better than PUR. This lighter steel wall system offers design options, and can be customized as smooth, ribbed, or waved as a structural panel or as a rainscreen for a low- or mid-rise cross-laminated timber (CLT) structure. These thinner wall systems also can mean a big difference in leasable space and build speed.

While the increase in product options is making it possible to build lower carbon footprint buildings, changing how we build starts with design and product specification. When architects make the decision to use a wall system that can reduce overall GHG emissions and embodied carbon, the impact of industrial buildings on the planet can be reduced and a net-zero future can be possible.