Data & LCIA Methods

ecoinvent v3.12 background data, CML/ReCiPe/EF v3.1 method selection, data quality (DQR, pedigree matrix) and uncertainty analysis — the layer that decides where your numbers come from and how much they can be trusted.

27 articles

2026-09-2212 min read

Recovery of organic waste: compost, biogas and open dumping

Organic waste substitutes no product; the credit comes entirely from avoided methane. Open dumping, landfill, composting and biogas compared on ecoinvent 3.12 data.

2026-09-1811 min read

Energy recovery or material recycling? Comparing the credits

The same tonne of plastic displaces electricity if burned and granulate if recycled — but the two credits are not the same size and cannot both be granted to one stream. The waste hierarchy, EN 15804 Table 13 and the formulae.

2026-09-1610 min read

LCA hotspot analysis: finding the biggest impact by contribution

Hotspot analysis shows which process, flow or module the total environmental impact comes from. The three axes of contribution analysis, the Pareto logic, hotspots that shift by impact category, and the move to a reduction scenario.

2026-09-139 min read

Reference service life and replacement schedule: B4 cost in LCC

Service life is the parameter that moves an LCC result most after the discount rate. Where RSL comes from, the replacement formula N = ceil(T/SL) − 1, residual value, the B2/B3/B4 distinction and how long-lived products get unfairly penalised.

2026-09-1211 min read

Transport in LCA (A4): tkm, load factor and empty return

A4 is the transport of the product from factory gate to site, calculated as mass × distance × a per-tkm factor. Vehicle class, utilisation, empty return and the trap of volume-limited products; the EN 15804 scenario table and a worked example.

2026-09-1012 min read

Recovery credits by material: from PET to aluminium

A tonne of recovered aluminium and a tonne of paper do not earn the same credit. The primary and secondary route, the order of magnitude of the credit and the specific trap for each of six materials.

2026-09-098 min read

Discount rate in LCC: real or nominal, and which rate?

The discount rate is the single assumption that moves an LCC result most. The real-versus-nominal distinction, the Fisher relation, typical ranges for public and private projects, the advantage of real terms under high inflation and a sensitivity example.

2026-09-0811 min read

Embodied carbon calculation at product and element scale: A1–A3

A product's embodied carbon is the sum of its A1–A3 emissions per declared unit. The formula, the A1/A2/A3 split, pulling values from EPDs, the biogenic carbon distinction and a worked example for 1 m² of wall.

2026-09-0610 min read

Recovery yield and substitution ratio: product per kg of waste

The two quiet multipliers of a recovery credit: yield, which describes process loss, and the substitution ratio, which describes quality. Catalogue yields by material, the moisture correction and downcycling.

2026-09-0211 min read

Recovery calculation: how to quantify avoided CO₂e and energy

A recovery calculation measures how much greenhouse gas and primary energy is avoided compared with the scenario in which a waste stream is not recovered. The formula, the four inputs and a worked 100-tonne PET example.

2026-09-0111 min read

How to calculate LCC: life cycle costing step by step

Life cycle costing (LCC) in seven steps: analysis period and functional unit, assigning items to EN 15804 modules, the real-versus-nominal decision, discounting and NPC, EAC, a worked example and sensitivity.

2026-06-1011 min read

Beyond GWP: why the other impact categories matter

Focusing on carbon can reverse some decisions. The real role of acidification, eutrophication, ozone, toxicity and resource depletion.

2026-06-099 min read

Digital EPDs: machine-readable formats and why PDF is not enough

EPDs are no longer read but processed. The ILCD+EPD data format, the digital product passport and direct import into building LCA tools.

2026-06-0811 min read

LCI databases: choosing between ecoinvent, EF and sector datasets

Choosing a background database is not a technical detail but a methodological decision that changes the result. Coverage, system models and why you must not mix.

2026-06-0710 min read

Primary and secondary data: which to collect for which line

Modelling everything with primary data is neither possible nor necessary. The foreground-background split and allocating a data collection budget well.

2026-06-0610 min read

ISO 14046 water footprint: withdrawn water is not consumed water

Counting litres is not a water footprint. Scarcity weighting, the consumption-versus-degradation split, and regional sensitivity.

2026-06-0310 min read

Scenario analysis: how end-of-life assumptions decide the result

Nobody knows what recycling infrastructure will look like in fifty years. How to work with that uncertainty and report scenarios honestly.

2026-06-0210 min read

Sensitivity analysis: which assumption is actually carrying the result?

An LCA result is only as solid as its weakest assumption. One-at-a-time scans, hotspot analysis and how this differs from uncertainty.

2026-05-158 min read

Foreground vs background data: getting the distinction right

The split between foreground (manufacturer-specific) and background (generic) data is the foundation of an LCA's scientific credibility. Practical rules and edge cases.

2026-05-1410 min read

DQR Pedigree Matrix: scoring inventory data quality on 5 dimensions

How does EN 15804+A2's mandatory DQR system work? The 1-5 scale on each of five dimensions, the aggregate score, and triggering sensitivity scenarios.

2026-05-1410 min read

ecoinvent activity selection: choosing the best fit on 3 criteria

Picking the right activity from ecoinvent's 21,000+ entries is a methodological decision. Geographic, technological and temporal representativeness.

2026-05-149 min read

Midpoint vs endpoint LCIA: which level for which decision?

Midpoint analysis offers 18+ categories; endpoint collapses to 3 main areas. The practical impact of characterisation, normalisation and weighting steps.

2026-05-1311 min read

CML vs ReCiPe vs IMPACT World+: which LCIA method when?

Differences between the three leading LCIA methods: midpoint vs endpoint, geographic resolution, EN 15804 and PEFCR alignment, academic use.

2026-05-1310 min read

EF v3.1 (Environmental Footprint): understanding the PEFCR-mandatory method

The EU Commission's EF method is mandatory under PEFCR. 16 categories, the normalisation and weighting reference set, and overlap with EN 15804.

2026-05-139 min read

GWP-100 vs GWP-20: how the time horizon shapes your LCA result

IPCC's 100-year and 20-year global warming potential factors yield different results. Methane can shift by 4×. Why and when does that matter?

2026-05-0911 min read

LCA for academia: a free template for your MSc thesis

Thesis structure for MSc students: goal-scope, inventory, impact assessment, interpretation. clca academic license at 50% off with real-time supervisor feedback.

2026-05-0911 min read

ecoinvent v3.12: what's new, and how clca exposes the cut-off / consequential / APOS variants

ecoinvent v3.12 was released in September 2025. New datasets, updated Turkish grid mix, the three system-model variants and automatic electricity calculation in clca.

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