The umbrella standard: ISO 14025

ISO 14025 sits at the top of the hierarchy. It doesn't define any product-specific rules — instead, it establishes what a "Type III environmental declaration" is in general: third-party verified, based on LCA, following a Product Category Rule. Every EPD, regardless of product or region, is a Type III declaration under this standard. See the full ISO 14025 reference page.

Construction-specific core rules: EN 15804 and ISO 21930

For construction products specifically, two "core PCR" standards sit one level below ISO 14025: EN 15804, the European standard, and ISO 21930, its international counterpart. Both define the shared structure every construction-product EPD must follow — the life-cycle modules, the required impact categories, how results get reported — so that EPDs for different products, written under different product-specific PCRs, are still structurally comparable.

Product Category Rules: the product-specific layer

A Product Category Rule (PCR) is the layer that actually varies by product. Written for a specific product category (ready-mix concrete, insulation, flooring) under one of the core standards above, it adds category-specific requirements: which additional impact indicators apply, what use-stage assumptions to make, how to handle product-specific end-of-life scenarios. An EPD can't be written without one — it's the document that tells an LCA practitioner exactly what to calculate and disclose for that product type.

How these standards relate to each other

In practice: ISO 14025 defines what a Type III declaration is, in general, for any product. EN 15804 or ISO 21930 defines what a construction-product declaration specifically must contain. A product-specific PCR, written under one of those core standards, defines the exact rules for one product category. An individual EPD is the finished document that follows all three levels at once — general declaration principles, construction-specific core rules, and product-specific detail, stacked in that order.

Regional and national variation

On top of the international layer, individual countries and regions add their own requirements — France's RE2020 regulation, Germany's national program alignment with EN 15804, and various "Buy Clean" procurement policies in US states, among others. These don't replace the standards above; they layer additional disclosure or compliance requirements on top. See Regional & Country Requirements for the specifics.

Frequently asked questions

Do I need to follow EN 15804 or ISO 21930?

It depends on where the EPD will be used. EN 15804 is required for EPDs registered under most European program operators and for CE marking-adjacent requirements in the EU. ISO 21930 is the more common reference outside Europe, including for LEED and other North American green building certifications. Many program operators accept either, or align the two.

What's the difference between a core PCR and a product-specific PCR?

EN 15804 and ISO 21930 function as 'core PCRs' — general rules for all construction products. A product-specific PCR (for example, one covering ready-mix concrete or insulation) sits on top of the core PCR, adding requirements specific to that product category, like which additional impact indicators to report or how to handle particular use-stage scenarios.

Can an EPD comply with more than one standard at once?

Yes, and it's common — many EPDs are written to satisfy both EN 15804 and ISO 21930 simultaneously, since the two are closely aligned. The declaration will typically state explicitly which standards it complies with.

Sources

  • ISO 14025:2006, Environmental labels and declarations — Type III environmental declarations — Principles and procedures
  • EN 15804:2012+A2:2019, Sustainability of construction works — Environmental product declarations — Core rules for the product category of construction products
  • ISO 21930:2017, Sustainability in buildings and civil engineering works — Core rules for environmental product declarations of construction products and services