Joan Ferrer, Commercial Director UK & Ireland of Ravago Building Solutions, discusses what can be done to make it easier for specifiers to compare and evaluate competing construction products.

Every relationship is built on a foundation of trust, from long-term strategic partnerships to small one-off transactional arrangements – each party needs to have faith that the other will deliver as promised. For manufacturers of construction products, that means assuring specifiers that their products will consistently perform to their advertised specifications.

The Code for Construction Product Information provides a framework for manufacturers to work within, encouraging greater transparency and promoting the adoption of mechanisms to ensure that information is up-to-date and accurate.  While this is a fantastic scheme, it doesn’t necessarily help specifiers with the task of comparing competing products as the implementation of the Code is specific to each manufacturer, having been moulded to their internal processes.

In theory, regulatory standards and third-party validated certification systems should make life easier. You should be able to take a quantitative approach to analysing two competing products, quickly comparing key characteristics to make a well-informed decision on what is best suited for your project. Unfortunately, theory and practice are not quite the same thing when it comes to evaluating construction materials. We now find ourselves in a place, where, instead of making decisions easier, an ever-burgeoning list of assorted stamps of approval can make direct comparisons difficult, even when you’re comparing products within the same class. Ultimately, not all certifications are created equal, and specifiers can find themselves lulled into a false sense of security at no fault of their own.

The blight of ‘NPD’ in conformity assessments
Universally recognisable, CE markings are just the end assessment of a swathe of different data points, and manufacturers have flexibility over what data is included in the Declaration of Performance (DoP). At Ravago Building Solutions, we’ve always sought to declare all of the data at our disposal, working hard to ensure that our UK manufacturing plant is fine-tuned for consistent performance. This allows us to state the lab results attained during initial type testing rather than resorting to Declarations of Performance littered with ‘NPD’ (No Performance Determined) to indicate that test data is unavailable. We believe in giving our customers access to all performance-related results; we only use NPD as a last resort and only when the value is immaterial.

However, this approach is certainly not a given, and other manufacturers may opt to disclose only the bare essentials if they have concerns about product consistency. Consequently, it can be a risk to take a CE mark at face value; in addition to checking for its prescence you need to make sure that you interrogate the underlying data points within the DoP.

The enigma of EPDs
The Construction Industry Council tells us that the built environment and construction sector is responsible for approximately 38 per cent of global carbon emissions. Given this, it is hardly surprising that sustainability is now a key focus throughout the industry and questions are being asked at all stages of the value chain. Ostensibly, Environment Product Declarations (EPDs), using a comprehensive life cycle analysis, provide a mechanism for comparing the environmental footprint of competing products. Third-party verification gives EPDs their credibility, however, look beneath the surface and the situation is murkier.

The prevalence of generic EPDs formulated using averages of pooled data from multiple manufacturers creates various problems when trying to compare products from competitors. How are you meant to know the relative performance of any given manufacturer represented by the EPD? Are they better than average, smack bang in the middle, or are they the underperformer that dragged the average down for everyone else?

Furthermore, given there are significant emissions associated with the transportation of construction materials, generic EPDs covering organisations across a wide geographical area can mask the true figures. If both a UK manufacturer and a Spanish manufacturer are using the same generic EPD, they are suggesting that their products will have to travel comparable distances to a project site in the UK. You don’t need to fire up Google Maps to know that one of them will be clocking up hundreds of additional haulage miles than the other.

Even when a manufacturer chooses to produce its own EPDs, their high cost means that it is often cost-prohibitive to produce a version for each individual product and separate manufacturing location. This is something that we have wrestled with at Ravago Building Solutions, eventually opting to commission an EPD for each class of product produced across our European manufacturing sites. While not perfect, it is certainly better than having to rely on a generic EPD, and our UK manufacturing facility means that our average transport distance is below the value stated in the certificate so the typical order will have a smaller transport emissions footprint than claimed.

Subtle differences in certification
Finally, let us consider third-party certification schemes and how not all of these are accredited by the government-appointed UKAS scheme. While not essential, it is comforting to know that a certifying body and their accessors have been validated as meeting internationally recognised standards of technical competence, including compliance with the ISO 17021 standard for conformity assessment. As it stands, only the British Board of Agrément (BBA) has been accredited by UKAS to provide certification for construction products.

The difference between the approaches taken by competing certification schemes are often subtle, but they can have a significant impact. For example, the BBA and KIWA handle lambda correction factors for inverted roof insulation in very different ways – this factor is critical to determining the thickness of insulation required to achieve a desired U-value.

While the BBA applies a moisture correction factor to the declared thermal conductivity to provide an accurate design value for U-value calculation purposes, KIWA uses the same declared and design thermal conductivity values while stating that the required thickness of insulation should be increased by not less than 10 per cent (as per guidance in BS EN 6229:2018). This relies on specifiers remembering to increase the thickness after the U-value calculation has been provided – something easily overlooked when calculations are included as part of a comprehensive tender package.

Take your time when comparing your options
While this patchwork quilt of systems and approaches creates challenges and it would be much easier if consistency was the order of the day, it is still infinitely better than not offering transparency. It is clear that we need to work harder as an industry to establish consistent standards for presenting technical information that will allow specifiers to quickly and easily compare competing solutions. In the meantime, people need to remain on their guard and remember that equivalence does not mean equal, and exercise due diligence when assessing their options.

For more information, please visit the Ravago Building Solutions website.