Sustainability Atlas
Food, Agriculture & Materials·15 min read··...

Deep dive: low-carbon materials (cement, steel, timber) — what's working, what isn't, and what's next

what's working, what isn't, and what's next. Focus on an emerging standard shaping buyer requirements.

Quick Answer

Cement, steel, and timber collectively account for approximately 15% of global CO2 emissions. In 2024-2025, the most effective decarbonization approaches include supplementary cite cementitious materials (SCMs) achieving 30-50% clinker substitution, electric arc furnace steelmaking using scrap and renewable electricity, and mass timber construction scaling through cross-laminated timber (CLT) and glulam applications. Failed approaches include carbon capture and storage (CCS) retrofits on cement plants (consistently delayed and over-budget), hydrogen-based steelmaking at commercial scale (stuck in demonstration phase), and monoculture timber plantations marketed as carbon-negative (facing certification challenges). The CSRD and emerging Environmental Product Declaration (EPD) requirements are reshaping European procurement, with buy clean mandates spreading to the US and Asia-Pacific.

Why This Matters

Buildings and infrastructure account for 37% of global energy-related CO2 emissions, with embodied carbon from materials representing a growing share as operational efficiency improves. For a typical office building, embodied carbon now equals 50+ years of operational emissions. As the building sector decarbonizes operations through electrification and renewable energy, materials become the dominant climate challenge.

The European Corporate Sustainability Reporting Directive (CSRD) now requires over 50,000 companies to disclose Scope 3 emissions, including embodied carbon in purchased materials. The EU Carbon Border Adjustment Mechanism (CBAM), fully operational from 2026, imposes carbon costs on imported cement and steel. These regulatory drivers are creating unprecedented demand signals for low-carbon materials.

For procurement professionals, understanding which low-carbon material pathways actually deliver emissions reductions is essential for meeting corporate climate commitments, maintaining regulatory compliance, and managing supply chain transition risks. The gap between marketing claims and verified performance remains substantial.

Key Takeaways

  • SCM-based low-carbon cements using calcined clay, fly ash, and slag achieve 30-50% emissions reductions at 5-15% cost premiums, with proven performance and growing availability
  • Electric arc furnace (EAF) steel using scrap feedstock and renewable electricity achieves 70-80% emissions reductions compared to blast furnace production
  • Mass timber construction is scaling rapidly in Europe, with CLT production capacity growing 25% annually and structural applications up to 18 stories now code-compliant
  • Carbon capture on cement plants has not achieved commercial viability, with all announced projects experiencing delays, cost overruns, or cancellation
  • Green hydrogen steelmaking remains in pilot phase, with commercial-scale production unlikely before 2030
  • Environmental Product Declarations (EPDs) are becoming mandatory for public procurement in the EU, UK, and several US states
  • Buy Clean policies in California, New York, and the EU set maximum embodied carbon thresholds that disqualify high-carbon imports

The Basics

Understanding Material Emissions Sources

Cement

Cement production generates approximately 8% of global CO2 emissions through two mechanisms: calcination (limestone decomposition releasing CO2 chemically bound in rock) accounts for 60% of emissions, while fuel combustion for kiln heating accounts for 40%. Decarbonization requires addressing both sources.

Steel

Steel production generates approximately 7% of global emissions. Integrated blast furnace-basic oxygen furnace (BF-BOF) production uses coal as both fuel and chemical reductant, generating 1.8-2.2 tonnes CO2 per tonne of steel. Electric arc furnace (EAF) production using scrap steel generates 0.3-0.6 tonnes CO2 per tonne, varying with electricity carbon intensity.

Timber

Timber serves as both structural material and carbon storage. Sustainably harvested timber sequesters 1.6-1.8 tonnes CO2 per cubic meter. However, lifecycle emissions depend heavily on forest management practices, transportation distances, and end-of-life treatment.

What's Working

1. Supplementary Cementitious Materials (SCMs)

SCMs replace a portion of Portland cement clinker with materials having cementite properties, reducing both calcination and fuel emissions proportionally. Key SCMs include:

  • Ground granulated blast furnace slag (GGBS): Byproduct of steel production, enables 50-70% clinker replacement in appropriate applications
  • Fly ash: Byproduct of coal combustion, enables 15-35% clinker replacement
  • Calcined clay: Abundant natural clay heated to ~800°C, enables 30-50% clinker replacement with minimal supply constraints
  • Limestone filler: Ground limestone enabling 5-15% clinker replacement with minimal performance impact

The LC3 (Limestone Calcined Clay Cement) technology developed by EPFL and IIT Delhi combines calcined clay and limestone to achieve 40% clinker reduction with performance meeting all standard cement specifications. Commercial LC3 production launched in India, Colombia, and Malawi in 2024, with European production beginning in 2025.

Heidelberg Materials and Holcim now offer SCM-based cements with verified EPDs showing 30-50% emissions reductions across their European portfolios. Cost premiums range from 5-15% depending on SCM type and local availability.

2. Electric Arc Furnace Steelmaking with Renewable Electricity

EAF steelmaking using scrap feedstock requires only electrical energy (no coal as reductant) and generates 70-80% lower emissions when powered by renewable electricity. The technology is commercially mature, with EAF representing 30% of global steel production in 2024.

SSAB's Hybrit initiative demonstrated fossil-free steel production in Sweden using green hydrogen for direct reduced iron (DRI) and renewable electricity for EAF processing. While hydrogen-based DRI remains in demonstration phase, EAF processing of scrap is commercially proven at scale.

ArcelorMittal, Nucor, and Tata Steel expanded EAF capacity significantly in 2024-2025, with EAF's share of global production projected to reach 50% by 2040. Nucor's EAF mills in the US Southeast achieve carbon intensities of 0.35-0.50 tonnes CO2 per tonne steel using 60%+ renewable electricity.

The constraint is scrap availability. Current global scrap supply supports approximately 30% of steel demand. Increasing EAF share requires either more scrap (from demolition of aging building stock) or low-carbon primary iron production.

3. Mass Timber Construction

Mass timber uses engineered wood products (CLT, glulam, laminated veneer lumber) as structural elements in multi-story buildings. The approach enables:

  • Embodied carbon reduction of 60-80% compared to steel/concrete frame construction
  • Carbon sequestration of 0.5-1.0 tonnes CO2 per cubic meter stored in buildings for structure lifetime (typically 50-100 years)
  • Construction speed improvements of 20-30% due to prefabrication and reduced on-site work

European building codes now permit mass timber structures up to 18 stories. Norway's Mjøstårnet (18 stories, 85.4 meters) and Austria's HoHo Wien (24 stories, 84 meters) demonstrate structural viability at scale. The US adopted mass timber provisions in the 2021 International Building Code, enabling structures up to 18 stories.

European CLT production capacity reached 4 million cubic meters in 2024, growing 25% annually. Major producers include Stora Enso, Mayr-Melnhof, and Binderholz. Cost premiums of 5-15% over concrete construction are offset by faster schedules in many projects.

The sustainability of mass timber depends critically on forest management. Certification under FSC or PEFC provides baseline assurance, but concerns about carbon accounting for harvested wood products and forest carbon stock maintenance require ongoing attention.

What Isn't Working

1. Carbon Capture and Storage on Cement Plants

CCS has been promoted as the primary cement decarbonization pathway for a decade, yet no commercial-scale cement CCS project is operational. Heidelberg Materials' Brevik project in Norway, the most advanced, has experienced multiple delays and cost escalations, with commercial operation now expected in 2025 at best.

Key challenges include:

  • High capital costs: CCS adds $100-150 per tonne cement to production costs, roughly doubling the price
  • Energy penalty: Capture processes require 30-40% additional energy, partially offsetting emissions reductions
  • Storage infrastructure: Cement plants are often located far from suitable geological storage sites
  • Retrofit complexity: Post-combustion capture must integrate with existing kiln operations without disrupting production

While CCS may eventually play a role in hard-to-abate residual emissions, its commercial viability remains unproven. Procurement professionals should not count on CCS-based low-carbon cement availability before 2030.

2. Commercial-Scale Green Hydrogen Steelmaking

Hydrogen-based direct reduction of iron ore (H2-DRI) could eliminate coal from primary steelmaking entirely. However, the approach requires:

  • Green hydrogen at prices below $2/kg (current costs: $4-8/kg in most regions)
  • Massive electrolyzer capacity consuming vast renewable electricity supplies
  • Modified DRI plants capable of using pure hydrogen (most current plants use natural gas)

SSAB's Hybrit project and ArcelorMittal's Hamburg demonstration have proven technical feasibility, but commercial-scale production remains years away. ThyssenKrupp's planned H2-DRI plant in Duisburg faces delays due to hydrogen supply uncertainty. The first commercial volumes are unlikely before 2028-2030.

For near-term procurement, EAF steelmaking with scrap and renewable electricity offers proven low-carbon pathways. Hydrogen-based primary steel will eventually be needed to address scrap supply limits, but should not be expected in commercial volumes within current procurement planning horizons.

3. Unverified Carbon-Negative Claims

Some timber producers market their products as "carbon negative" based on forest carbon sequestration claims that do not withstand scrutiny. Common issues include:

  • Accounting for carbon releases at end-of-life when wood is burned or decomposes
  • Ignoring foregone forest carbon storage if timber harvest reduces forest carbon stocks below no-harvest baselines
  • Monoculture plantations that provide timber but minimal biodiversity or ecosystem services
  • Missing chain-of-custody between certified forests and actual products

Robust carbon accounting for timber requires lifecycle assessment following ISO 14040/14044 and EN 15804 standards, with transparent assumptions about forest management, transportation, and end-of-life treatment. Third-party verified EPDs provide the most reliable basis for comparison.

Decision Framework

Material CategoryReady NowEmerging (2025-2027)Future (2028+)
Low-carbon cementLC3, SCM blends (30-50% reduction)Carbon-cured concrete, alkali-activated materialsCCS retrofit (if proven viable)
Low-carbon steelEAF with scrap + renewables (70-80% reduction)DRI with natural gas + EAFH2-DRI at commercial scale
Low-carbon timberFSC/PEFC certified CLT, glulamNovel wood products (CLT hybrids)Engineered bamboo, agricultural residue panels

Practical Examples

Example 1: Skanska's ECOncrete Program in the Nordics

Skanska partnered with Heidelberg Materials to develop and deploy low-carbon concrete across Scandinavian construction projects. The ECOncrete product line uses GGBS and calcined clay to achieve 30-50% embodied carbon reduction while meeting all structural specifications.

Outcome: Between 2022-2025, Skanska specified ECOncrete for 127 projects totaling 2.3 million cubic meters of concrete. Verified EPDs documented average carbon intensity of 180 kg CO2/m³ compared to 320 kg CO2/m³ for conventional concrete. The program prevented an estimated 322,000 tonnes CO2 emissions. Cost premiums averaged 8%, offset by accelerated permitting in municipalities prioritizing low-carbon construction.

Example 2: Nucor's Low-Carbon Steel for Automotive Supply Chains

Nucor developed Econiq, a certified low-carbon steel product using EAF processing with 100% renewable electricity and domestic scrap feedstock. The product achieves carbon intensity of 0.35 tonnes CO2 per tonne steel, 80% below global average.

Outcome: General Motors, Ford, and Mercedes-Benz signed multi-year supply agreements for Econiq steel in 2024, collectively representing 1.2 million tonnes annual volume. Automotive manufacturers met Scope 3 reduction targets for body-in-white components while maintaining equivalent material properties. The 15-20% cost premium was absorbed in vehicle pricing as sustainability differentiation. Nucor expanded EAF capacity by 2 million tonnes to meet demand.

Example 3: Stockholm's Strandparken Mass Timber Social Housing

Stockholm municipality commissioned Strandparken, a 31-unit social housing project constructed primarily from CLT, as a demonstration of low-carbon affordable housing. The eight-story building achieved structural completion in 14 weeks using prefabricated CLT panels.

Outcome: Lifecycle assessment documented 65% reduction in embodied carbon compared to equivalent concrete construction. Construction schedule was 35% faster than comparable concrete projects, reducing financing costs and accelerating occupancy. Residents reported superior acoustic performance and thermal comfort. The project cost 7% more than conventional construction but achieved net savings when schedule acceleration was valued. Stockholm has since mandated lifecycle carbon assessment for all municipal construction procurement.

Common Mistakes

1. Accepting Unverified Sustainability Claims

Suppliers increasingly market products as "low-carbon" or "green" without third-party verification. Procurement should require Environmental Product Declarations conforming to EN 15804+A2 (Europe) or ISO 21930 (international), with verification by accredited third parties.

2. Ignoring Scope 3 Upstream Emissions

EPDs typically cover cradle-to-gate emissions (production only). For complete lifecycle assessment, procurement must also consider transportation distances (Scope 3 Category 4) and construction process emissions. A low-carbon cement transported 2,000 km may have higher lifecycle emissions than conventional cement produced locally.

3. Overweighting Novel Technologies

Novel approaches like carbon-mineralized concrete, geopolymer cements, and mycelium-based materials generate media attention but lack commercial scale or performance track records. Procurement should prioritize proven technologies (SCM cements, EAF steel, certified mass timber) while maintaining awareness of emerging options for future specifications.

4. Treating All Timber as Carbon-Negative

Mass timber provides genuine emissions benefits when sourced from sustainably managed forests, but not all timber is equivalent. Procurement should require chain-of-custody certification, transparent EPDs, and ideally evidence that harvested timber comes from forests with stable or increasing carbon stocks.

FAQ

Q: How do Environmental Product Declarations (EPDs) work, and what should procurement look for?

A: EPDs are standardized, third-party verified documents reporting product lifecycle environmental impacts, including global warming potential (embodied carbon). Look for: conformity with EN 15804+A2 or ISO 21930, verification by an accredited program operator (EPD International, IBU, UL Environment), recent issue date (within 5 years), and transparent system boundaries (cradle-to-gate vs. cradle-to-grave). Compare products using consistent functional units (e.g., kg CO2 per cubic meter of concrete at specified strength class).

Q: What carbon intensity thresholds should procurement specify for each material category?

A: Current best practice thresholds based on 2024-2025 commercial availability: Cement/concrete: Below 250 kg CO2/m³ for normal-strength concrete (C30/37), below 350 kg CO2/m³ for high-strength (C50/60). Structural steel: Below 1.0 tonne CO2/tonne for EAF products, below 1.8 tonnes CO2/tonne for BF-BOF (current global average is 1.85). Mass timber: Below 150 kg CO2/m³ for CLT including biogenic carbon storage credit. These thresholds should tighten 5-10% annually as supply scales.

Q: How does the EU Carbon Border Adjustment Mechanism (CBAM) affect material procurement?

A: CBAM requires importers of cement and steel to purchase certificates matching the embedded carbon content of imports, priced at EU Emissions Trading System levels (currently EUR 80-100/tonne CO2). This eliminates cost advantages of high-carbon imports from regions without carbon pricing. Procurement must factor CBAM costs into supplier comparisons for non-EU materials. From 2026, CBAM will roughly double the landed cost of high-carbon imported cement and add 10-20% to high-carbon steel costs.

Q: What is the role of carbon offsets in material procurement?

A: Offsets should not substitute for actual emissions reductions in materials. The Science Based Targets Initiative does not accept offsets for Scope 3 target achievement. Procurement should prioritize genuinely low-carbon materials with verified EPDs. If offsets are used for residual emissions after maximizing reductions, ensure they meet quality standards (Verra VCS, Gold Standard) with robust additionality and permanence verification.

Key Players

Established Leaders

  • HYBRIT (SSAB/LKAB/Vattenfall) — Swedish consortium pioneering hydrogen-based steel. Commercial plant launching 2026 with 1.2M tonnes/year capacity.
  • Heidelberg Materials — Global cement leader with evoZero net-zero cement. World's first CCS cement plant at Brevik, Norway capturing 400,000 tonnes CO2/year.
  • ArcelorMittal — World's largest steelmaker with hydrogen-DRI facilities in Germany, Belgium, and Spain.
  • Stora Enso — Leading cross-laminated timber (CLT) manufacturer for mass timber construction.

Emerging Startups

  • H2 Green Steel — Building fossil-fuel-free steel plant in Sweden. €750M EIB funding, production starting 2024-2026.
  • CarbonCure — Injects CO2 into concrete during production. Used in 600+ plants globally.
  • Sublime Systems — Electrochemical cement production eliminating kiln emissions.
  • Brimstone Energy — Carbon-negative cement technology using silicate rocks.

Key Investors & Funders

  • EU Innovation Fund — €143M to HYBRIT, €3.6B to green industrial projects.
  • European Investment Bank — €750M to H2 Green Steel.
  • Breakthrough Energy Ventures — Backing cement and steel decarbonization startups.

Action Checklist

  • Establish material embodied carbon requirements in procurement specifications, referencing maximum allowable global warming potential per functional unit
  • Require Environmental Product Declarations conforming to EN 15804+A2 or equivalent for all structural materials, verified by accredited program operators
  • Develop approved supplier lists based on verified EPD performance, updating annually as supply improves
  • Include Scope 3 emissions in supplier evaluation criteria, weighting carbon performance alongside price, quality, and delivery
  • Specify chain-of-custody certification (FSC, PEFC) for all timber procurement, with preference for suppliers demonstrating forest carbon stock maintenance
  • Calculate CBAM cost implications for any imported cement or steel, incorporating into total cost comparisons
  • Engage suppliers on decarbonization roadmaps, understanding planned investments in low-carbon production capacity
  • Track and report embodied carbon in completed projects, building organizational capability for CSRD compliance
  • Participate in industry coalitions (First Movers Coalition, SteelZero, ConcreteZero) to signal demand and accelerate market development

Sources

Topics

regenerativeCSRDresilienceScope 3water

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