I have been quietly observing what my customers have been saying over the past few months, specifically, about energy efficiency. Most now are doing their research online before having us come out to measure up for their new windows and doors, which is obviously great as it means they are serious about buying and not just tyre kicking. But what I have been finding increasingly is that they are mentioning U-Values a lot more now.

In the past few months, I have been asked more and more often about U-Values, what they are, how they work etc. Customers are actually looking at these things in detail and seeking to find out more about them. For fans of U-Values, this should come as good news.

For those who have followed posts on DGB about this, or followed the debate in general, you’ll know that the generally accepted commentary on this issue is that U-Values are more accurate than WERs. I think we all know of the well stated issues that WERs have faced within the industry, and continue to do so.

Thanks to the internet, and the growing amount of material on U-Values now filtering down to the homeowner, education about U-Values is finally winning through. But lets be honest, U-Values have never been that difficult to grasp in the first place. The lower the number the better. The problem they had was exacerbated a few years ago when the powers that be decided that WERs would be better because it came with that aesthetically pleasing and recognisable A-G scale certificate. I can understand why they went down that route, but I think long term it was the wrong choice.

One of the other major factors as to why U-Values are gaining momentum with the public is their wide use among doors. Composites especially. For probable obvious reasons, DERs, or Door Energy Ratings do not get anywhere near the sort of exposure WERs do, most likely down to the fact that most door suppliers have chosen to go down the U-Value route when promoting the energy efficiency of their doors. This means all promotional material, online and printed, that ends up with the homeowner will mention U-Values at some point.

It is the use of them with doors that is now helping that cross over into the window market.

I had a surprising but pleasing comment from a customer the other day. He said to me that he thought that window energy ratings were daft because the number that tags on to an A or A+ ratings just keeps getting higher and higher. He says that to him, the higher it goes, the less importance it has as it starts to look over the top. And right there lies a problem I have mentioned on here before.

The higher the number gets, the more silly it’s going to look. Technology will always continue to get better, so it is only reasonable to think that in a short space of time, we could be seeing A+30 or A+40 windows hitting the market regularly. But from a homeowner’s perspective, how much tangible difference is there going to be between an A+30 and A+40 windows? Probably not that much. And when that argument starts to crop up, those numbers at the end of the letters very quickly lose their importance. It’s like buying a 40 terabyte hard drive for home usage. It’s way too big for that sort of application, when a 1TB hard drive will serve them just as well.

For me, long may this continue. In the future of energy efficiency, U-Values are going to play an increasingly important role, and we’re probably seeing the start of this right now.