Here’s a subject I know many in the industry like to get their teeth stuck into once in a while: U-Values vs WERs. Got my eye on the comment section ready for this one.

One thing that struck me at the FIT Show this year was the very heavy emphasis by many of the exhibitors on the U-Values of their products, and much less in the way of Window Energy Ratings. Many were now even demonstrating the wind and water resistance measurements as USPs, even over Window Energy Ratings.

From what I saw, we can probably expect this to be a big feature of our industry in the coming years. In my eyes, that’s a good thing.

Ease and simplicity

There has to be a reason as to why U-Values are making a big push at places like the FIT Show. For me, it could be down to the very efficiency of the products now being produced.

As with all technologies, as time goes on, it always gets better. Windows and glazing are no different. As each year passes, we grind gradually higher in terms of what our windows and doors are capable of in terms of energy efficiency. They only get better, never worse. The problem however is that this constant forward progress puts pressure on WER certificates.

When they were first introduced it was a simple A-G rating scale, something that most home owners would recognise. We are all aware of the flaws of this system, so I won’t keep going there. But the other problem is that as energy efficiency only gets better, the scales have to be re-adjusted each time. For example, an A rated window has a score of 0-9, then you add a + symbol for every ten after that. The end result is that you can have windows with numerous +’s after their A rating, which begins to make a mockery of the certification.

That is why I believe manufacturers are starting to look heavily into U-Values again. Long considered the more accurate way to measure the heat loss of our products, I got a strong sense of this at the FIT Show this year by much of the marketing by many major suppliers.

And it makes sense. U-Values are easy for both the industry and home owners to understand once it has been explained to them. The lower the number of the U-Value the better. Not difficult, and the maths behind this measurement are tried and tested. But it perhaps now looks more appealing on the page rather than an “A” with a long list of +’s after it. I still believe that there are many suppliers out there who see U-Values are the more legitimate way to market the energy efficiency of their products.

DGB Business

Influence from other areas?

I think there has been some influence from other areas of our industry too. For example the solid roof market. One of the biggest USPs of many roof makers has been their U-Values. There’s no official energy ratings certificate for roofs, but U-Values can be measured, and some of them are so low that any sort of heat loss is becoming difficult to measure. The advantage for suppliers of solid roof makers however is in the marketing. Being able to advertise U-Values that are close to zero is a very powerful thing.

I believe that many window suppliers might be looking at this, seeing the marketing advantages super-low U-Values bring, and are now choosing to promote that to installers in a much more obvious way than WERs.

What I was struck by at the FIT Show was how many suppliers were now showing off the ratings of their products when it comes to wind and water. Something I haven’t seen at other shows before, but a clear demonstration by suppliers to try and find that one extra USP over their competitors. To be fair, some of the products I saw could have been classed as flood-proof doors, and could easily withstand winds of major hurricane forces or even at the top of Everest. Not that the UK gets extremes like this, but it’s always good to have those figures in your back pocket.

Point is, I believe manufacturers are moving towards more technical measures in an effort to pull in the business. There are only so many +’s you can stick on the end of “A” before it starts to look daft on the page and loses credibility. Instead, it is more technical measurements, like U-Values, that are going to be the key stats in the years to come, and we can expect to see new window products coming to the market which are going to boast some seriously impressive U-Values.

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