Introduction: GWP Moves from Voluntary to Regulated
GWP sub-indicators (total, fossil, biogenic, luluc) will be required in Declarations of Performance under CPR 2024/3110 — once new harmonised technical specifications are published for each product family.
Global Warming Potential has been a core indicator in Environmental Product Declarations for over a decade. Every EPD published under EN 15804+A2 reports GWP values across life-cycle modules, broken down into four sub-indicators. For manufacturers with EPD programmes, reporting GWP is business as usual.
What is changing is the regulatory context. CPR 2024/3110 elevates GWP from a voluntary sustainability metric to a regulated product characteristic that will eventually be declared in the Declaration of Performance (DoP) alongside mechanical, fire, and thermal properties. Annex I, Part B of the regulation specifies four GWP sub-indicators that must be reported for construction products covered by new harmonised technical specifications.
This article provides a practical guide for manufacturers: what GWP data the CPR requires, where that data comes from, how it relates to existing EPD programmes, and what steps to take now — even though the implementing technical specifications have not yet been published.
Timeline clarity: GWP declaration under the CPR is not yet mandatory for any product family. It becomes mandatory only after new harmonised technical specifications (hTS) are published in the Official Journal and the coexistence period with old standards expires. Current estimates place the earliest mandatory GWP declarations for priority products (cement, concrete, steel, insulation) in the 2029–2031 timeframe. This guide prepares manufacturers for that horizon.
What CPR 2024/3110 Requires: The Four GWP Sub-Indicators
Annex I, Part B: Environmental Sustainability
CPR 2024/3110 Annex I lists the essential characteristics that may be required in a Declaration of Performance. Part B — Environmental Sustainability — introduces four GWP sub-indicators:
| Indicator | Abbreviation | Unit | What it measures |
|---|---|---|---|
| GWP-total | GWP-total | kg CO₂ eq. | Total global warming potential from all sources |
| GWP-fossil | GWP-fossil | kg CO₂ eq. | Emissions from fossil fuel combustion and processes |
| GWP-biogenic | GWP-biogenic | kg CO₂ eq. | Emissions/removals from biogenic carbon (biomass) |
| GWP-luluc | GWP-luluc | kg CO₂ eq. | Emissions from land use and land use change |
These four sub-indicators correspond exactly to the GWP breakdown already required by EN 15804+A2 for construction-product EPDs. This alignment is deliberate — the CPR’s GWP requirements are designed to draw on the existing EPD/LCA infrastructure.
Life-Cycle Modules in the DoP
The CPR does not specify which life-cycle modules must be included in the GWP declaration — that detail will be defined in each product-family’s harmonised technical specification. However, the minimum scope under EN 15804+A2 (modules A1–A3 and C1–C4) is expected to be the baseline, with some hTS potentially requiring additional modules (A4–A5, B, or D) depending on the product category.
Practical implication: If your EPD covers modules A1–A3 and C1–C4 (cradle-to-gate plus end-of-life), you will have the minimum GWP data needed for the DoP. If your EPD is cradle-to-grave (A1–C4 plus D), you will have full coverage for any hTS scope.
Where GWP Data Comes From: The EPD–DoP Connection
The LCA Foundation
GWP values in an EPD are derived from a Life Cycle Assessment (LCA) conducted according to EN 15804+A2. The LCA quantifies all greenhouse gas emissions associated with the product across its life cycle, using characterisation factors from the EU Environmental Footprint (EF 3.0/3.1) method to convert individual gas emissions into CO₂ equivalents.
The LCA is typically performed by a qualified LCA practitioner using specialised software (e.g., SimaPro, GaBi/Sphera, openLCA) and background databases (ecoinvent, GaBi databases). The resulting GWP values are then reported in the EPD and verified by an independent third party before publication.
From EPD to DoP: The Data Flow
Under CPR 2024/3110, the GWP values declared in the DoP will be based on the same LCA data used for the EPD. The data flow is:
Data flow: LCA → EPD → DoP
- LCA study — quantifies GWP per declared/functional unit across life-cycle modules
- EPD — publishes verified GWP values under a programme operator (e.g., EPD Polska)
- DoP — declares GWP values as essential characteristics alongside mechanical/fire/thermal properties
The EPD does not replace the DoP — it feeds the DoP with verified environmental data.
Declared Unit vs. Functional Unit
An important technical detail is the distinction between the declared unit (used in cradle-to-gate EPDs, e.g., 1 tonne of cement) and the functional unit (used in full life-cycle EPDs, e.g., 1 m² of wall assembly providing specified thermal resistance over a 50-year reference service life). The hTS for each product will specify which unit type must be used for the DoP GWP declaration.
| Unit type | When used | Example | Typical products |
|---|---|---|---|
| Declared unit | Cradle-to-gate (A1–A3) EPDs | 1 tonne of cement CEM I 42.5 R | Cement, aggregates, steel, timber |
| Functional unit | Full life-cycle (A–D) EPDs | 1 m² insulation at R = 3.0 m²K/W for 50 years | Insulation, windows, cladding systems |
Practical Guide: Preparing Your GWP Declaration
Step 1: Inventory Your Existing EPDs
Start by mapping your product portfolio against your existing EPD coverage:
- Which products have current EPDs? Check expiry dates — an expired EPD may need renewal or update before the data can be used in a DoP.
- Are EPDs EN 15804+A2-compliant? EPDs published under the older +A1 methodology use different characterisation factors and may not include GWP-biogenic and GWP-luluc as separate sub-indicators. These need to be updated to +A2.
- What scope do your EPDs cover? Minimum scope for DoP compatibility: A1–A3 and C1–C4. Full scope (A1–D) provides maximum flexibility.
Step 2: Identify Data Gaps
For products without EPDs, or with outdated EPDs, identify the data gaps that need to be filled:
- Upstream data — do you have specific data for raw material suppliers (A1), or are you relying on generic database values?
- Manufacturing data — do you have accurate energy consumption, process emissions, and waste data for your production facilities (A3)?
- Transport data — do you have representative transport distances and modes for raw material delivery (A2)?
- End-of-life scenarios — do you have data or assumptions for how your product is treated at end of life (C1–C4)?
Data quality matters: EN 15804+A2 requires a data quality assessment. Producer-specific data (primary data from your own operations) is ranked higher than generic data. Products declared with producer-specific data will have more accurate and often more favourable GWP values than products relying on conservative generic assumptions.
Step 3: Commission or Update Your LCA
If you need to commission a new LCA or update an existing one:
- Select a qualified LCA practitioner — look for practitioners experienced with EN 15804+A2 and your product category’s specific PCR (Product Category Rules).
- Collect primary data — gather at least 12 months of production data covering energy consumption, raw material inputs, emissions, waste, and outputs.
- Choose appropriate background data — use ecoinvent, GaBi, or other recognised databases for upstream processes you do not control directly.
- Define scenarios — for modules beyond A3, define realistic transport distances, use-phase assumptions, and end-of-life scenarios based on your product’s typical application.
An LCA study for a single product typically takes 2–4 months for data collection and modelling. Add 1–2 months for independent verification and EPD publication. Plan accordingly.
Step 4: Publish Your EPD
Select a programme operator for EPD publication. Key considerations:
- International recognition — choose a programme operator that participates in ECO Platform mutual recognition, ensuring your EPD is accepted across EU markets and in international Buy Clean programmes.
- PCR alignment — ensure the programme operator has published or adopted a PCR for your product category that aligns with EN 15804+A2.
- Digital availability — check that the EPD is published in machine-readable formats (ILCD+EPD, EN 15804 XML) that can feed into building-level LCA tools.
EPD Polska, as a member of ECO Platform, provides internationally recognised EPD publication for construction products, with full EN 15804+A2 compliance and machine-readable data formats.
Step 5: Prepare for DoP Integration
Once your EPD is published, prepare for the eventual integration of GWP data into your Declarations of Performance:
- Map GWP data to DoP fields — identify where the four GWP sub-indicators will appear in your DoP format.
- Set up data management — establish workflows for keeping DoP GWP values synchronised with EPD updates.
- Train your compliance team — ensure that the staff responsible for DoP preparation understand the GWP data requirements and the EPD–DoP data flow.
Common Pitfalls and How to Avoid Them
| Pitfall | Risk | How to avoid |
|---|---|---|
| Using +A1 methodology EPDs | Incompatible GWP sub-indicators | Update to EN 15804+A2 methodology |
| Relying entirely on generic data | Conservative GWP values, competitive disadvantage | Collect producer-specific primary data for A1–A3 |
| Expired EPDs | Data not accepted for DoP | Renew EPDs before expiry (typically 5-year validity) |
| Incomplete module coverage | Cannot meet hTS scope requirements | Commission full A1–C4 (or A1–D) LCA scope |
| Waiting for hTS publication | Rush and bottleneck when standards are published | Start EPD programme now — LCA practitioners will be in high demand |
The Bottom Line
GWP declaration under CPR 2024/3110 will transform environmental performance from a voluntary differentiator to a regulated product characteristic — on par with compressive strength, fire reaction, or thermal conductivity. The data source is the Life Cycle Assessment, the delivery vehicle is the EPD, and the regulatory expression is the Declaration of Performance.
The timeline gives manufacturers a preparation window. Use it wisely: audit your product portfolio, commission or update EN 15804+A2-compliant EPDs, collect producer-specific data, and build the internal workflows that will connect EPD data to your DoP system. When the first new harmonised technical specifications are published, you will be ready.
Information current as of publication date. GWP declaration obligations take effect after publication of new harmonised technical specifications and expiry of coexistence periods — currently estimated no earlier than 2029 for priority product families.