How EPDs work

If you buy, specify or sell construction products, you will meet EPDs. Architects ask for them, tenders score them, building rules in several European countries use them, and the new EU Construction Products Regulation builds on the same indicators. An EPD is how one company hands another a verified LCA result in a format both can read.

Think of it as an audited cost sheet for the environment. The supplier did the calculation, an independent verifier checked it against a published rulebook, and a programme operator put it on the record.

What an EPD is

An Environmental Product Declaration (EPD) is a document that reports the results of a life cycle assessment of a product, calculated to a set of predefined rules and checked by an independent party. The international standard behind it is ISO 14025:2006, which calls EPDs Type III environmental declarations.

Three features make an EPD different from a claim on a website:

1. It follows fixed rules. The rules for each product group are set in advance in product category rules (PCRs), so two EPDs to the same PCR are built the same way.
2. It is verified. An independent verifier checks the underlying LCA and the declaration before it is published.
3. It sits in a programme. A programme operator runs the system: it publishes the PCRs, organises verification, registers each EPD and keeps a public library.

ISO 14025 says EPDs are mainly intended for business-to-business communication. They report numbers; they do not say whether a product is “good” or “green”.

Who is involved

Role	What they do	Examples
Manufacturer (EPD owner)	Commissions or carries out the LCA, owns the EPD and is responsible for it	Any producer
LCA practitioner	Builds the model and writes the background report	In-house team or consultant
Programme operator	Runs the programme: general instructions, PCRs, registration, publication	The International EPD System (EPD International), IBU in Germany, EPD Norge
Verifier	Independently checks the LCA and the EPD against the standard, the PCR and the programme rules	Individual verifiers or certification bodies approved by the programme
PCR committee	Writes and reviews the product category rules	Industry, experts and other stakeholders, organised by the programme

Many European programme operators for construction EPDs belong to ECO Platform, an association that publishes shared verification guidelines so that EPDs from different programmes are checked in a consistent way.

Product category rules

A PCR is the recipe for a product group: which unit to declare, which life cycle stages to include, how to allocate, which data to use and what to report.

For construction products in Europe, the recipe has two layers:

• EN 15804 is the core PCR for all construction products and services. The current version is EN 15804:2012+A2:2019 (usually written EN 15804+A2), with a corrigendum published in 2021.
• Complementary PCRs (sometimes written c-PCRs) add rules for a specific product group, such as precast concrete, insulation or steel. Programme operators publish these, and CEN has published some as standards: EN 16757, for example, is the c-PCR for concrete and concrete elements.

Outside the EN framework, ISO 21930:2017 plays a similar core role internationally.

The first thing to check

Which PCR was used? Two EPDs are only comparable if they follow the same core rules and declare the same unit in the same way. An EPD to the older EN 15804+A1 is not directly comparable with one to EN 15804+A2: the impact methods changed.

The modules of EN 15804+A2

EN 15804 splits a construction product’s life into modules, labelled with a letter for the stage and a number for the step. This modular layout is the single most useful thing to learn about construction EPDs, because every results table is organised this way.

A1–A3 Product

Product stage, cradle to factory gate.

• A1 Raw material supply
• A2 Transport of raw materials to the factory
• A3 Manufacturing

Usually reported as one combined A1–A3 column.

A4–A5 Construction

Construction process stage.

• A4 Transport from the factory to the building site
• A5 Installation into the building, including installation waste

B1–B7 Use

Use stage.

• B1 Use (emissions from the product itself while in use)
• B2 Maintenance
• B3 Repair
• B4 Replacement
• B5 Refurbishment
• B6 Operational energy use
• B7 Operational water use

C1–C4 End of life

End-of-life stage.

• C1 Deconstruction or demolition
• C2 Transport to waste processing
• C3 Waste processing for reuse, recovery or recycling
• C4 Disposal

D Beyond

Module D: benefits and loads beyond the system boundary. The net effect of materials or energy that leave the product system and replace something else, such as scrap steel that replaces primary steel. It is reported separately and should not simply be added to the other modules.

Which modules must be declared

Under EN 15804+A2, most EPDs must declare A1–A3, C1–C4 and D. The ECO Platform verification guidelines list the EPD types the standard allows:

• cradle-to-gate with modules C1–C4 and D;
• cradle-to-gate with options (some of A4–B7), plus C1–C4 and D;
• cradle-to-grave (all modules) plus D;
• cradle-to-gate only (A1–A3), or with options, but only where the product meets the standard’s exemption conditions.

A module that is not declared is marked ND (not declared) in the results table. ND is not zero. It means “we did not calculate this”.

The indicators

EN 15804+A2 aligned construction EPDs with the EU Environmental Footprint impact methods. The results table reports each indicator per module.

Core environmental impact indicators:

Short name	What it measures
GWP-total	Climate change, total
GWP-fossil	Climate change from fossil sources
GWP-biogenic	Climate change from biogenic carbon (carbon taken up and released by plants and wood)
GWP-luluc	Climate change from land use and land use change
ODP	Ozone depletion
AP	Acidification
EP-freshwater, EP-marine, EP-terrestrial	Eutrophication (nutrient over-enrichment) in three compartments
POCP	Photochemical ozone formation (summer smog)
ADP-minerals&metals	Depletion of mineral and metal resources
ADP-fossil	Depletion of fossil resources
WDP	Water deprivation potential (water use weighted by local scarcity)

GWP-total is the sum of the other three GWP indicators.

Additional indicators (optional in the standard, sometimes required by a programme): particulate matter, ionising radiation, ecotoxicity in freshwater, human toxicity (cancer and non-cancer) and land use (soil quality). Several of these carry a warning in the EPD that results should be used with care, because the methods are still uncertain.

EPDs also report resource use (renewable and non-renewable primary energy, secondary materials, fresh water), waste categories (hazardous, non-hazardous, radioactive) and output flows (components for reuse, materials for recycling, exported energy).

Some programmes add their own indicator. EPD International, for example, also reports a GWP-GHG indicator. Read the footnotes to see how each one is defined.

Validity

An EPD is not valid for ever. ECO Platform’s verification guidelines expect the cover page to show the date of issue and a validity of five years, and EPD International sets a normal validity of five years. After that, the manufacturer must update and re-verify the EPD, or it expires. Programmes may also require updates within the validity period if the product or its data change significantly.

Where to find EPDs

• Programme operator libraries. Each programme publishes its EPDs, for example the EPD International library, the IBU EPD database and EPD Norge.
• The manufacturer’s website, although always check the registration number against the programme’s library to confirm the EPD is current.
• Building LCA tools and national databases, which import EPDs for designers to use.

Exercise

A precast concrete wall panel EPD shows these columns in its results table: A1–A3, A4, A5, B1–B7 marked ND, C1, C2, C3, C4, D.

1. What type of EPD is this?
2. A colleague adds A1–A3 and D together to get “the footprint”. What is wrong with that?

Answer

1. Cradle-to-gate with options (A4 and A5), with modules C1–C4 and D. The use stage is not declared.
2. Module D is reported beyond the system boundary. It is a potential benefit (or load) from recycling or reuse after the product’s life, and EN 15804 keeps it separate so readers can see it. Adding it to A1–A3 also skips the end-of-life modules C1–C4 and the construction modules A4–A5. If you need a single figure, say which modules you summed, and report D next to it rather than inside it.

What you should now be able to do

• Explain what an EPD is and what makes it different from a supplier’s own claim.
• Name the roles of the manufacturer, programme operator, verifier and PCR.
• Read the EN 15804+A2 module labels A1 to D and say what each stage covers.
• Name the core indicators, and explain why ND is not zero.
• Find an EPD in a programme library and check it is still valid.

Sources

• ISO 14025:2006, Environmental labels and declarations: Type III environmental declarations: Principles and procedures, iso.org.
• ISO 21930:2017, Sustainability in buildings and civil engineering works: Core rules for environmental product declarations of construction products and services, iso.org.
• ECO Platform, Verification Guidelines for ECO EPD Programme Operators, V8.0, December 2024 (EPD types, cover page validity, data age).
• EPD International, General Programme Instructions and PCR for construction products (EN 15804+A2).
• EPD International, c-PCR for concrete and concrete elements (EN 16757).
• IBU, PCR guidance texts for building-related products (Part B, precast concrete) (module table and indicator abbreviations).

Checked: 2026-09-29