Sustainable construction has rightly become a growing priority within our industry. We’re often being asked by our customers about the carbon footprint data for our products and ranges. But, there are different ways to measure the carbon footprint of a product – so how can you ensure you’re looking at the right data in order to make the right comparisons? In this blog I’ll be exploring how carbon footprinting has evolved over the years, the rise of EPDs and how we can make best use of the data.
Carbon footprinting is not new to us. We started working with the Carbon Trust 15 years ago to benchmark our operational emissions, and this led to a project with them to determine how best to calculate product carbon footprints. We even sat on the steering group that helped them to develop the methodology that’s now in PAS 2050 – the method for quantifying carbon footprints. It’s fair to say that at the time, product carbon footprints weren’t at the forefront of everyone’s mind or indeed of great interest to many in the industry.
One of the issues was that carbon footprinting was in its infancy and there was no central body in place to dictate a standard approach to carbon measurement, so it took some bold pioneering to forge the path ahead. Fast forward to 2023 and carbon footprinting has developed significantly and rightly, there is now a tremendous amount of scrutiny on the data that's being shared. Every business is motivated to report its carbon performance, but it’s still not straightforward to make fair, meaningful comparisons between different products.
Environmental Product Declarations (EPDs)
EPDs have now fast become the construction industry's preferred format for collecting and communicating a product’s environmental credentials. Every EPD is made up of lots of data about a product’s environmental impact, including amongst many other things, aspects such as water usage, ozone depletion or crucially the Global Warming Potential (or GWP); effectively the carbon footprint. The data in all EPDs, no matter which supplier, is collated and presented in a consistent format, allowing for comparisons to be made between different products. To give the customer confidence in what they are looking at, all EPDs are developed in line with international standards and whilst the data contained within is technically unaudited, all EPDs must be verified by a third party before being published to ensure a level of scrutiny, rigour, and consistency.
Tips for comparing EPDs
There are a few simple things to look out for when comparing EPDs to ensure that you're making like-for-like comparisons:
1. What’s the footprint boundary?
Data in an EPD is broken down into modules that make up a product's whole lifecycle. Modules A1-A3 (raw materials, transport and manufacturing) reflect the element of the footprint within the supplier’s control (‘cradle to gate’). A4 (Transport from factory to the project site) is the last module the supplier might have defendable data on and it represents the impact of the manufacturing location. It ensures that the GHG emissions associated with the delivery from the factory to site is also accounted for. This is important for instance, when we are talking about imported products. The remaining modules (A5-D) are ‘scenario-based assumptions’ – estimates of what happens when a product is installed, used, repaired, removed, and treated at the end of its life. There is no standard set of assumptions in our industry so it’s important to interrogate an EPD to check what claims are being made and whether they seem credible.
2. What’s the defined unit?
This is key as different EPDs will report on different units. The defined unit is always included in an EPD, so it’s important to note which unit has been used so you’re not comparing a tonne of material to a m3 of material, or a linear metre of pipe to a full 2.5m long section. A simple process of converting the units to ensure you are comparing like for like will ensure you come to valid conclusions.
3. What’s the service life being claimed?
If two EPDs show the same numerical carbon footprint, but one product lasts twice as long as the other, then that product effectively emits half the carbon of the one that needs to be replaced more frequently, so make sure you’re once again comparing like for like!
EPDs are here to stay and they’re a great tool for our industry to move towards more sustainable materials and construction. The best approach to take is to interrogate the information and use the EPD to get a good understanding of the environmental credentials of a product. To play our part, we’ve now published EPDs for over 80% of our products – with more to come later this year. For more information, check out our EPD Library.