What is an EPD (Environmental Product Declaration)?

Quick Answer: An Environmental Product Declaration (EPD) is a standardised document that quantifies the environmental impact of a product across its lifecycle, from raw material extraction through to disposal. EPDs are produced according to ISO 14025 and EN 15804 standards and are independently verified by a third party. They are used in procurement, construction, and carbon accounting to provide product-specific emissions data that is more accurate than generic industry averages.

What is an EPD (Environmental Product Declaration)?

An Environmental Product Declaration is a verified, third-party document that communicates the environmental performance of a product based on a Life Cycle Assessment (LCA). Rather than relying on broad estimates, an EPD provides product-specific data covering a defined set of environmental indicators, with global warming potential (measured in kg CO2e) typically being the most referenced.

EPDs are governed by ISO 14025, the international standard for Type III environmental declarations, and in the construction sector are further guided by EN 15804. To be published, an EPD must be independently verified by an accredited third party and registered with a recognised programme operator, such as EPD International, the Institut Bauen und Umwelt (IBU), or the RICS-backed Declare database.

The result is a document that buyers, specifiers, and carbon accountants can trust as a credible, comparable source of product-level emissions data.

What does an EPD contain?

An EPD documents environmental performance across a series of life cycle stages, often referred to using module notation from EN 15804.

The modules are grouped into four stages:

• Product stage (A1-A3): raw material extraction, transport to manufacturer, and manufacturing itself. This is the most commonly reported stage and is sometimes called "cradle to gate."
• Construction process stage (A4-A5): transport to site and installation.
• Use stage (B1-B7): performance in use, maintenance, repair, replacement, and operational energy and water use.
• End of life (C1-C4): deconstruction, transport, waste processing, and disposal. Some EPDs also include a D module covering reuse, recovery, or recycling potential beyond the system boundary.

Within each stage, the EPD reports against a standard set of environmental indicators. These include global warming potential, ozone depletion potential, acidification, eutrophication, and resource consumption. For carbon accounting purposes, the global warming potential figure (expressed in kg CO2e per declared unit) is the primary number most users are interested in.

Why do EPDs matter for carbon accounting?

When a company calculates its Scope 3 emissions, particularly those arising from purchased goods and services (Category 1) or capital goods (Category 2), it needs emissions data for the products it buys. The default approach is to use spend-based emission factors: broad averages derived from economic input-output models that estimate emissions per pound spent in a given industry sector.

Spend-based factors are a practical starting point, but they carry significant uncertainty. Two products in the same category can have very different carbon footprints depending on how and where they are made. An EPD replaces that estimate with a verified, product-specific figure, which improves the accuracy of a company's footprint considerably.

This matters for several reasons. Procurement teams making decisions based on carbon data need that data to reflect actual product differences, not category averages. Clients and frameworks increasingly expect activity-based data rather than spend-based proxies. And as Scope 3 reporting becomes more scrutinised, the quality of underlying data becomes a credibility question, not just a methodology one.

Seedling supports the use of EPDs and other product-specific carbon factors (including Product Carbon Footprints) as inputs to carbon accounting, allowing companies to move beyond spend-based analysis for their highest-impact purchased products.

How is an EPD different from a product carbon footprint?

These two terms are often used interchangeably, but they are not the same thing.

A Product Carbon Footprint (PCF) is a single-metric assessment of the greenhouse gas emissions associated with a product across its lifecycle, expressed in kg CO2e. It focuses exclusively on climate impact.

An EPD is broader. It includes global warming potential (which is essentially the PCF figure) alongside a wider set of environmental indicators covering resource use, water, and other impact categories. An EPD also follows a more prescriptive methodology, must be independently verified, and must be registered with a programme operator before it can be published.

In practice, a PCF is often produced as part of the EPD process. If a supplier has a published EPD, the global warming potential figure within it serves as the product carbon footprint for carbon accounting purposes.

What types of EPD are there?

Not all EPDs cover a single product from a single manufacturer. There are three main types:

Specific EPDs cover a single product from a named manufacturer. These provide the most precise data and are the most useful for carbon accounting and procurement decisions.

Industry average EPDs (sometimes called sector or generic EPDs) cover a product category and report average performance across multiple manufacturers. These are more widely available but less precise than specific EPDs. They are still significantly more accurate than spend-based emission factors.

Company-wide EPDs cover a range of products from a single manufacturer under one declaration, where the products are sufficiently similar in composition and process.

For carbon accounting, a specific EPD is the most accurate option. An industry average EPD is a reasonable step up from a spend-based factor where a specific EPD is not available.

Where are EPDs most commonly required?

EPDs originated in the construction sector and remain most prevalent there. Building materials, structural products, insulation, cladding, and fit-out products are the categories with the deepest EPD coverage. Green building rating schemes including BREEAM, LEED, and WELL reference EPDs as evidence of environmental performance in materials specification.

Beyond construction, EPD adoption is growing in manufacturing, electronics, and consumer goods, driven by procurement requirements, supply chain disclosure expectations, and frameworks such as the Science Based Targets initiative (SBTi), which encourages companies to improve data quality in their Scope 3 inventories over time.

Public procurement is also an increasing driver. Frameworks such as PPN 006 in the UK require suppliers to report on carbon, and buyers are beginning to ask for product-level data to support those disclosures. As that expectation moves further down supply chains, EPDs become a practical tool for suppliers who want to give their customers credible, usable data rather than estimates.

For companies building a carbon inventory, the presence of EPDs in a supply chain is a signal that data quality can improve year on year, which is exactly the direction credible carbon reporting needs to travel.