Environmental Product Declarations (EPD)

Environmental Product Declarations have been produced in construction for years, which puts the sector unusually far ahead on environmental data and creates a specific set of misunderstandings about what an EPD actually says.

What an EPD is

An EPD is a Type III environmental declaration: quantified environmental data for a product, based on life cycle assessment, calculated to a product category rule and verified independently.

Three properties distinguish it from a company’s own environmental figure. It follows a category rule rather than a bespoke method, it is verified by a third party, and it is published in a standard format that another party can read.

The module structure

EN 15804 divides the lifecycle into modules, and which modules a declaration covers is the single most important thing to establish before using its numbers.

A declaration covering only A1 to A3 is described as cradle to gate. It stops at the factory gate and says nothing about getting the product to site, installing it, maintaining it, or what happens at the end of the building’s life.

Why module scope breaks comparisons

Comparing a cradle-to-gate figure with a cradle-to-grave figure is the most common misuse of EPD data, and it systematically favours whichever product declared fewer modules.

The last node is the one specialists insist on and non-specialists skip. Comparing a kilogram of steel against a kilogram of timber tells you nothing useful, because a structure needs different quantities of each to achieve the same performance.

Module D and its controversy

Module D records benefits beyond the system boundary — the value of material that will be recycled or recovered after the product’s life ends.

It is reported separately from the other modules precisely because it is different in kind. Modules A to C record what happens; module D records a projected benefit contingent on a future recycling system behaving as assumed.

The controversy is that materials with high recycling potential can show a large module D credit, and presenting a total that nets module D against the rest can make a high-impact material appear low-impact. The standard’s response is to require it be reported separately, which only helps if the reader observes the separation.

How EPDs relate to the passport

The CPR recast under Regulation (EU) 2024/3110 brings environmental characteristics into declared performance, which moves EPD-type data from a voluntary document into a regulated declaration.

That changes its legal character considerably. A voluntary EPD is a marketing and procurement document; a declared environmental characteristic under the CPR carries the same weight as a structural performance declaration and the same consequences for getting it wrong.

The passport is the vehicle through which that declaration becomes reachable. An EPD published as a PDF on a manufacturer’s website is a document; the same data as structured values against a resolvable product identifier is something a design tool can query.

What manufacturers should do

For manufacturers with EPDs already, the work is structural rather than analytical, and it is smaller than starting from nothing.

Convert existing declarations from documents into structured data keyed to product identifiers, retaining the module scope and declared unit as attributes rather than as text in a header. Establish which products have current declarations and which have expired, since EPDs have validity periods that lapse quietly.

For manufacturers without EPDs, the sequence starts with finding the relevant category rule, because it determines the data collection required and there is no point gathering inventory data before knowing what boundary it must cover.

One further point saves expensive rework. Decide the declared unit before collecting anything, because it governs how production data must be allocated and it is not straightforward to change afterwards. A declaration per kilogram and one per square metre require different plant data even for an identical product.

The choice should follow how the product is specified in practice rather than how it is manufactured. Designers select insulation by area and thermal performance, not by mass, and a declaration expressed in units nobody specifies in will be converted by whoever reads it — usually incorrectly.