Cradle‑to‑Gate (C2G)

Cradle-to-Gate (C2G) covers all stages from the extraction and processing of raw materials to the point at which the finished product leaves the factory gate. It excludes transport to the customer, the use phase and end-of-life, and is the most commonly used system boundary in Environmental Product Declarations (EPDs) for resource-intensive sectors (cement, steel, aluminium, chemicals) and for B2B comparisons of embodied impacts.

Stages included within the C2G boundary

• Extraction and beneficiation of mineral, agricultural or forest resources
• Primary transformation (smelting, clinker production, polymerisation)
• Internal energy generation (boilers, cogeneration)
• Manufacturing, assembly and packaging up to the dispatch warehouse
• Management of in-house waste and emissions (disposal, incineration, HEPA/ESP treatment)

Step-by-step methodology according to ISO 14044

1. Define goal and scope: functional unit (e.g., 1 t of clinker, 1 kg of PET pellets)
2. Collect primary data: raw-material, fuel, water, electricity and additive consumption; internal transport
3. Allocate burdens in the case of coproducts (economic, mass, or energy allocation)
4. LCI modelling: build inventory flows using databases such as ecoinvent v3.9, GaBi or Agrifootprint
5. LCIA: calculate impact indicators (GWP100, AWARE, CED, ADP—Abiotic Depletion Potential)
6. Interpret results & hotspots: define ecodesign actions or supplier changes

Key indicators for responsible procurement

• Embodied carbon footprint (kg CO₂e) per functional unit
• Embedded blue-water use (m³) weighted by AWARE factor
• Recycled content (%) and potential recyclability
• Non-renewable primary energy (MJ)
• Material Circularity Indicator (MCI) for critical materials

Operational advantages of the C2G boundary

• Requires 30–50% fewer data points than a Cradle-to-Grave LCA, speeding up footprint generation
• Enables comparability among suppliers in public procurement and green purchasing
• Focuses on embodied impacts, which can represent up to 80% of GWP in near-zero-energy buildings
• Supports early-stage ecodesign, enabling material or clinker-ratio changes before the use phase

Limitations and considerations

• Does not capture use-phase emissions (e.g., cleaners, paints, tyres)
• May underestimate impacts when use or maintenance energy is significant
• Risk of local optimisation without assessing real recyclability or available infrastructure
• Need to harmonise region-specific metal datasets for fair comparisons

Case study: Aluminium façade panel (EU, 2024)

Functional unit: 1 m² powder-coated panel
Initial C2G footprint: 46 kg CO₂e · 1,200 MJ · 0.9 m³ blue water

• Bauxite → primary aluminium: 83% of GWP
• Powder coating: 11%
• Packaging & auxiliary energy: 6%

Intervention: replace 50% primary aluminium with post-consumer scrap + 100% solar PPA electricity
Result:

• 23 kg CO₂e (–50%)
• 640 MJ (–47%)
• 0.4 m³ blue water (–55%)
  Incremental cost: +6%, recovered within two years due to zero-emission building requirements (Level(s))

Regulatory and market linkages

• ESPR Regulation: Digital Product Passport will require C2G reporting for durability and recycled content
• EU Green Taxonomy: construction projects must demonstrate ≤ 0.4 t CO₂e/m² embodied up to Gate
• LEED v4 (MRc1): rewards C2G EPDs + 10% reduction in two key materials
• CBAM: cement and steel imports must declare C2G emissions for border adjustment

Evolution toward circular models

• Implement take-back schemes and remanufacturing to close loops and move toward Cradle-to-Cradle
• Design product-as-a-service models that retain manufacturer ownership and ensure product return
• Integrate material digital twins to track recycled content across the life cycle

The Cradle-to-Gate approach balances rigour and practicality: it enables comparison of materials and suppliers, optimises embodied-carbon footprints and supports compliance with emerging regulations. While it does not capture the entire life cycle, it is a decisive step toward circularity and environmental transparency, especially when complemented by use-phase and end-of-life data in continuous-improvement strategies.