The required level of data detail in a Life Cycle Assessment (LCA) depends on the study’s scope, objective, and framework. Internal studies for eco-design can rely on simplified data, while verified Environmental Product Declarations (EPDs) or ISO-compliant LCAs require high data quality, transparency, and completeness according to the relevant standards.
Summary
- Start from available data — site totals, supplier data, component lists. 
- Refine over time — move toward process-level, raw-material-level, and transport-specific data. 
- Be transparent — document every assumption, gap, and estimation. 
- Align with the framework — simplified for internal use, strict for ISO/EPD publications. 
Granularity should always match the study’s ambition: broad approximations are acceptable for scoping and design support, while formal declarations require fully traceable, verifiable data across all life-cycle stages.
For more details, please read the article below.
1. Granularity Depends on the Scope and Framework
The starting point is the system boundary — whether the study is cradle-to-gate, cradle-to-grave, or another configuration.
- Simplified internal LCA (eco-design use): flexible approach; level of detail driven by data availability and study goals. 
- ISO-compliant LCA (ISO 14040/14044): requires traceability of all significant energy and material flows and transparent documentation of assumptions. 
- EPD (Environmental Product Declaration): governed by the product’s PCR (Product Category Rules) and by EN 15804/A2 in the construction sector, which prescribe mandatory indicators and data quality rules. 
2. Data Granularity by LCA Stage
| 
 LCA Stage 
 | 
 Preferred Data Detail 
 | 
 If Missing 
 | 
 Minimum Mandatory Data 
 | 
| 
 Goal & Scope 
 | 
 Clear definition of system boundaries, functional unit, and included life-cycle modules 
 | 
 Adjust scope to align with available data 
 | 
 Functional unit, boundaries, declared exclusions 
 | 
| 
 Raw Materials 
 | 
 Material-level composition (mass or % per material) 
 | 
 Use manufactured component list or supplier emission factors 
 | 
 Main materials or components covering >90% of product mass 
 | 
| 
 Manufacturing 
 | 
 Energy and inputs per process or machine 
 | 
 Use annual site totals and allocate by product volume or weight 
 | 
 Total site energy use, allocation rule, key inputs 
 | 
| 
 Transport (Inbound/Outbound) 
 | 
 Factory of origin and destination for each product, distances per mode (truck, ship, air) 
 | 
 Use average distance weighted by shipment volumes 
 | 
 Origin/destination (or average), transport mode, estimated distance 
 | 
| 
 Use Phase 
 | 
 Real use conditions, energy, maintenance data 
 | 
 Apply default or sector averages 
 | 
 Usage scenario or representative assumption 
 | 
| 
 End-of-Life 
 | 
 Recycling rates, treatment routes, transport to end-of-life 
 | 
 Use default sector values 
 | 
 Main disposal/recycling assumptions 
 | 
| 
 Impact Assessment 
 | 
 Full characterization of all flows per ISO or PCR 
 | 
 Apply standard methods for global warming, energy, waste 
 | 
 At least mandatory impact indicators (e.g. GWP, energy use) 
 | 
| 
 Interpretation 
 | 
 Sensitivity and uncertainty analysis 
 | 
 Transparent discussion of missing data 
 | 
 Explanation of gaps and expected influence 
 | 
3. If You Can’t Provide Certain Data
Missing data must never be ignored silently. ISO 14044 requires that each missing or estimated value be:
- Explicitly identified and justified; 
- Replaced by data from similar processes or secondary databases when possible; 
- Evaluated for completeness, typically aiming to cover 90–95 % of all relevant flows. 
When no reliable data exist, adjust the study boundary or clearly label the gap as an exclusion. Always describe the potential effect of that exclusion on overall results.
4. Data Quality and Documentation Requirements
According to ISO 14044, all datasets must specify:
- Temporal, geographical, and technological representativeness; 
- Source, precision, completeness, and uncertainty; 
- Consistency and reproducibility of data collection. 
For EPDs (EN 15804/A2):
- Data must meet the quality rules defined in the relevant PCR; 
- Each module (A1–A3, A4–A5, etc.) has mandatory reporting requirements; 
- Minimum indicators include energy use, GWP, water use, and waste categories. 

