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An in-depth look at Environmental Product Declarations EPDs

Article by Rob Firman, Technical and Specification Manager, Polyfoam XPS for AT Journal issue 142, summer 2022.

1 Introduction
2 EN 15804
3 Environmental impacts
4 Life cycle assessment
5 Sustainability
6 Types of EPD
7 Watch points
- 7.1 Functional equivalence
- 7.2 Product stages
8 Certification
9 The future
10 Related external links
11 Related articles on Designing Buildings

[edit] Introduction

Environmental product declarations, or EPDs, are documents that communicate environmental impact. They can be created for products and services of all types, but this article specifically deals with EPDs as they relate to construction products. Within the construction industry, there is more demand for product manufacturers to make EPDs available. Design professionals increasingly want to select products with EPDs for the projects they are working on.

However, there is a danger that simply specifying a product with an EPD is seen as making a ‘sustainable’ choice. Is that actually the case? What life cycle data are EPDs based on? How do you compare EPDs, and how can EPDs contribute to certification schemes like BREEAM? In this article, we’ll try to answer all of those questions.

[edit] EN 15804

How does EN 15804 relate to construction product EPDs?

An EPD is an internationally-recognised document that is created in accordance with applicable standards – and should be independently verified to confirm it meets those standards.

EN 15804:2012 Sustainability of construction works. Environmental product declarations. Core rules for the product category of construction products describes the reporting of environmental impact for construction products. The standard’s most recent amendment was in 2019.

The contents of EN 15804 are extensive, but some of its key aspects are: it defines parameters that should be declared and how they should be reported; it describes the life cycle stages that can be assessed; and it specifies the quality of data required for reporting.

The full title for an EPD is a ‘Type III environmental product declaration’, which means the EPD’s environmental data has been quantified in accordance with the ISO 14040 series of standards.

[edit] Environmental impacts

An EPD reports on the following six environmental impacts.

Global warming potential.
Depletion of the stratospheric ozone layer.
Acidification potential of soil and water.
Eutrophication potential.
Formation potential of tropospheric ozone.
Abiotic depletion potential.

[edit] Life cycle assessment

What is life cycle assessment in EPDs?

Life cycle assessment (LCA) makes assumptions about the environmental impact at different stages of a product’s life cycle. An EPD then describes and reports the conclusions of the LCA in a standard format, so designers, specifiers and other construction professionals can make informed decisions.

LCA is done across five stages, which are reported in four modules from A to D.

The five stages are:

Product, construction process (these two stages make up module A together),
Use (module B)
End of life (module C)
Circular economy (module D)

Each module contains numbered sub-categories, and manufacturers currently choose the scope of a product’s LCA reporting.

By covering product manufacturing and construction on site, Module A encompasses activities up to a building’s practical completion. As the name ‘use’ suggests, module B deals with the operation of a building, including the maintenance, repair, replacement and refurbishment of products. Module C, the ‘end of life’ stage, addresses what happens to products when a building is no longer required. It assesses impacts relating to deconstruction and demolition, and the processing of waste for reuse, recovery or recycling, or disposal.

The full title of module D is ‘Benefits and loads beyond the system boundary’, which reflects a shift to the circular economy from the linear economy. When materials and products can have their useful life extended across multiple projects then the positive impact of that can be reported here.

[edit] Sustainability

Does having an EPD make a product sustainable?

An EPD does not describe whether a product is ‘sustainable’ or not. In fact, it is important to remember that there is no such thing as a ‘most sustainable’ product. EPDs are simply a tool, allowing the environmental impact of products to be compared so that choices can be made in support of a construction project’s sustainability goals. Processing raw materials, manufacturing products, and constructing and maintaining buildings, all adds to environmental impact. Minimising the impact of construction starts with the efficient use of resources, so that we simply consume less.

This is why it has become more common for people to say that the most sustainable building is the one that doesn’t need to be built. Questioning whether new construction is necessary, or if a client’s needs can be met through the reuse of an existing building, means the use of raw materials and new products can be prioritised for where they are most needed.

The number of available EPDs has grown substantially in the last ten years, but the scope of reporting across different EPDs is not consistent. When data is reported for more stages, the picture of a product’s environmental impact becomes more complete.

Product choices can then be made which prioritise the efficient use of resources over the long term. The focus, arguably, should therefore be on making assessment and reporting are as comprehensive as possible, from module A through to module D.

[edit] Types of EPD

What are the different types of EPD?

The scope of LCA reporting in EPDs is just one way in which comparing EPDs from different manufacturers is tricky. It is only through comparing EPDs for different products that an assessment can be made as to which ones contribute to a project’s sustainability goals.

To make a proper comparison between EPDs, it is necessary to look for, and understand, the similarities and differences between them.

[edit] Generic EPDs

Generic EPDs are typically offered by trade associations and feature data for similar products, produced by a range of manufacturers. A trade association gathers data from its member companies, then reports the environmental impact of the averaged data in an EPD.

It is therefore possible to request an EPD from multiple manufacturers, and be provided with the same document.

A generic EPD can be broadly representative of the environmental impact of your product specification. There will always be a question as to exactly how accurate it is, however, especially if a project is unique in a way that isn’t captured by an average.

The preference should be for a manufacturer-specific EPD or, even better, a product-specific EPD.

[edit] Manufacturer-specific EPD

A manufacturer-specific EPD can apply to more than one product (within a specific category of products) produced by a single manufacturer.

[edit] Product-specific EPD

A product-specific EPD applies to a single product from a single manufacturer. In seeking to be transparent about the environmental impact of construction projects, the more specific the data the better.

[edit] Watch points

What are some of the other differences between EPDs?

The environmental impact of a construction product is reported for a ‘unit size’ of that product. The EPDs that Polyfoam XPS makes available, for example, are based on one cubic metre of our extruded polystyrene insulation.

[edit] Functional equivalence

This unit size is called the ‘functional equivalence’, and it’s important to check whether different EPDs are using the same one. Two products can have a similar environmental impact, but a difference in functional equivalence results in very different figures reported by the EPDs.

[edit] Product stages

It is also important to check which stages or modules of life cycle assessment have been included in an EPD’s reporting.

‘Cradle to gate’ refers to the processes involved with manufacturing a product and it leaving the factory. ‘Cradle to practical completion’ also deals with the installation of the product on site, being covered by modules A1 to A5. ‘Cradle to grave’ spans the complete life cycle of a product, including its use and what happens to it at the end of life.

The scope of reporting for similar types of products might be different, and that difference should be taken into account when assessing environmental impact. As EPDs continue to mature, consistent reporting across all modules will be increasingly desirable to give the fullest possible picture.

[edit] Certification

Claiming credits for EPDs in BREEAM and LEED Certification schemes make credits available if construction products have EPDs. The number of credits depends on the type of EPD and whether the EPD has been externally verified.

BREEAM requires EPDs to be verified by a third- party. For the Mat 02 category, it awards points based on whether EPDs are generic (0.5 points), manufacturer- specific (0.75 points) or product-specific (1.5 points). However, if an EPD is not externally verified to EN 15804 then it cannot contribute to claiming points.

Increased recognition of EPDs has come at the expense of Green Guide to Specification ratings. Green Guide ratings were removed from the 2018 BREEAM New Construction standard and, as older versions of BREEAM fall out of use, will eventually become completely redundant.

The LEED certification scheme also recognises the importance of externally verified EPDs, and then places different values on different EPD types. It awards 0.25 points for generic EPDs, up to a full point for product- specific EPDs.

[edit] The future

EPDs will only become more important and relevant regardless of whether voluntary certification is being sought, EPDs are being requested to support carbon emissions reductions and net zero carbon targets.

EPDs report a variety of environmental impacts, including global warming potential (GWP) and ozone depletion potential (ODP). Declarations of GWP are starting to become a requirement of centrally-funded government projects.

Like other mandates that have come before, such as BIM, once these things become the norm on public projects, a trickle-down effect tends to occur as different parties get used to asking for, seeing and sharing the information. EPDs are therefore going to be an ever- present part of construction product specification.

This article originally appeared as ‘An in-depth look at EPDs’, issue 142 of the AT Journal, summer 2022. The article was written by Rob Firman, Technical and Specification Manager at Polyfoam XPS for CIAT.

--CIAT