Building a low-carbon future: The role of alternative materials in reducing embodied carbon

When we think of buildings and climate change, our minds often go to operational emissions: the energy needed to heat, cool, and power spaces. But another critical component is embodied carbon—the greenhouse gas (GHG) emissions tied to extracting, manufacturing, transporting, and installing the materials for building construction.

By 2050, embodied carbon could comprise up to half of all lifecycle emissions in high-efficiency buildings, according to a recent report. Unlike operational emissions, which can be reduced over time through efficiency upgrades and renewable energy, embodied carbon is locked in upon building construction.

Addressing embodied carbon is therefore critical to improving how the built environment interacts with natural ecology, supports communities, and tackles climate change. Four key materials—steel, concrete, wood, and insulation—represent some of the most impactful opportunities for transformation.

Steel is one of the most carbon-intensive materials in modern construction; steel production alone is responsible for roughly 7% of global GHG emissions. Traditionally, steelmaking relies on coal in blast furnaces, which produces vast amounts of carbon dioxide (CO₂). However, new pathways are emerging that could decarbonize steel production.

One promising innovation is hydrogen-based steelmaking, pioneered by initiatives such as HYBRIT in Sweden, which uses hydrogen—produced from renewable energy—instead of coal to remove oxygen from iron ore. This process nearly eliminates CO₂ emissions while producing only water vapor as a byproduct

In the U.S., companies like Nucor are advancing low-carbon techniques by recycling scrap steel in electric arc furnaces driven by renewable energy and scrap recycling. Meanwhile, Boston Metal is developing molten oxide electrolysis technology, which uses electricity instead of fossil fuels to separate iron from ore, representing another potential breakthrough.

Green steel remains costly, but the opportunities it presents are immense. Decarbonizing steel would transform one of the most “hard-to-abate” industries into a cornerstone of the low-carbon economy.

Concrete is the most widely used building material in the world—and cement, its key ingredient, is responsible for around 8% of global CO₂ emissions. Traditional cement production involves burning limestone and other materials in high-temperature kilns using coal, producing emissions mainly from fuel combustion and the CO₂ released as limestone becomes clinker, a key component of cement production.

Electrification of kilns using renewable energy offers one pathway to remove fossil fuel combustion from cement production. Emerging technologies are also exploring carbon capture and utilization, as well as alternative binders that reduce or replace clinker altogether. These innovations could dramatically reduce the embodied carbon of concrete without sacrificing performance, durability, or scalability.

One especially compelling player is Sublime Systems, a startup developing an ambient-temperature, fully electrified, electrochemical cement-making process. Rather than burning limestone, Sublime’s process applies electric current to non-carbonate feedstocks—so CO₂ is not released in the process—to isolate reactive materials needed for cement. Their approach is thus “true zero” in that it avoids emissions from both fossil fuel combustion and limestone decomposition.

As with steel, the obstacles include the high capital costs of retooling plants, securing reliable clean electricity, and ensuring consistent quality standards. Yet, given concrete’s ubiquity, even incremental reductions in its carbon footprint could have massive global impact.

Wood, when sourced responsibly, is a powerful tool in reducing embodied carbon. Mass timber—engineered wood products such as cross-laminated timber—can replace steel and concrete in structural applications, offering strength and significant carbon storage benefits. Every cubic meter of mass timber sequesters roughly a ton of CO₂, enabling mass timber to serve as carbon storage throughout a building’s lifespan.

Beyond reducing embodied carbon, mass timber presents additional construction benefits that make it an appealing alternative to reinforced-steel-concrete construction. Using mass timber can shorten construction timelines, reduce the need for exterior materials by requiring less space between floors, and provide an appealing warmth to interior spaces. The stunning Ascent MKE, the tallest mass timber multifamily community in the world bridges luxury and sustainability—demonstrating how mass timber can play a key role in developing high-demand buildings with significantly reduced carbon impact.

The key is ensuring sustainable harvesting practices. Unsustainable logging or land-use changes that result in loss of old-growth forests can negate climate benefits, making certification and traceability essential for wood-based products. But when sourced sustainably, mass timber presents incredible opportunities to develop more nature-inspired buildings that elevate the look, feel, and functionality of our built environment.

Insulation is critical for reducing a building’s operational energy use, but conventional insulating materials such as polystyrene and polyurethane are derived from fossil fuels. Fortunately, innovative bio-based alternatives are emerging.

Mycelium insulation, grown from the root structure of fungi, offers excellent thermal performance and is fully biodegradable. Similarly, hemp insulation provides effective thermal and acoustic properties with low embodied carbon. These natural materials not only reduce reliance on oil-based derivatives but also sequester carbon during their growth phase.

Numerous companies are working to promote the resurgence of industrial hemp, not only for its application in building materials but also for its capacity to regenerate land. C-Biotech demonstrates how industrial hemp can remove toxins from soils and then be harvested for use as construction material. Hemp is also fast growing and not nearly as water intensive as other commercial crops, giving it an amazing capacity to help combat climate change and restore degraded land.

Scaling production and gaining wider market acceptance remain hurdles, but as green building certifications and tenant demand drive change, bio-based insulation is positioned to become a mainstream solution.

Addressing embodied carbon will require a blend of new technologies and millennia-old materials. Commercial real estate owners and developers are uniquely positioned to accelerate solutions. By specifying low-carbon materials, setting procurement standards, and forming strategic partnerships, the industry can send market signals powerful enough to transform supply chains.

Industry leaders are already moving. Prologis, Microsoft, and Meta recently became founding members of the Sustainable Concrete Buyers Alliance, strengthening demand for low-carbon materials and accelerating the path to net zero. With first-mover advantage, these companies are shaping more resilient supply chains and gaining a competitive edge amid growing stakeholder expectations for sustainability.

Ultimately, reducing embodied carbon is not just about compliance or certification—it’s about resilience, cost efficiency, tenant appeal, and climate leadership. By leveraging their scale and influence, commercial real estate owners can catalyze a market shift that brings low-carbon materials into the mainstream.

The future of sustainable buildings depends not only on how efficiently they operate, but on how responsibly they are made.

This article was written by Gabe John, Senior Communications Manager at Verdani Partners. Learn more about Verdani Partners here.