Rob Firman on understanding different types of environmental product declarations and how they support project certification.
IN the May 2022 issue of Contract Flooring Journal (CFJ) we looked at environmental product declarations (EPDs) and what they say about the sustainability of construction materials and products. We established EPDs aren’t statements of whether products are sustainable. Instead, EPDs are tools for reporting environmental impact.
It’s only through comparing the EPDs of different products that an assessment can be made as to which ones contribute to the sustainability goals of a construction project overall.
To make a proper comparison between EPDs provided by different manufacturers, it’s necessary to look for, and understand, the similarities and differences between them. Understanding the types of EPD available also gives an indication of the points or credits that can be awarded for them under schemes such as BREEAM and LEED.
What are the different types of EPD?
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’s 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’ll 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.
A manufacturer-specific EPD can apply to more than one product (within a specific category of products) produced by a single manufacturer. 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.
What are some 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.
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.
It’s also important to check which stages or modules of lifecycle 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 onsite, being covered by modules A1 to A5. ‘Cradle to grave’ spans the complete lifecycle 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.
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.
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 become an ever-present part of construction product specification.
technical@polyfoamxps.co.uk
www.polyfoamxps.co.uk
Rob Firman is specifications and technical manager at Polyfoam
