The ramifications of the updated Building Regulations are becoming known as each day and week passes. As I understand it, there continues to be discussions at high levels about the implementation of them, in particular when it comes to new rules on background ventilation and the much talked about trickle vents.
But one other area of the fenestration sector that is at risk of serious disruption is Window Energy Ratings. Should trickle vents be installed in all windows, whether it is retrofit work or new-build, this is going to have a significant impact on WERs and their future.
Window Energy Ratings at risk?
Window Energy Ratings, provided by the BFRC, has been a mainstay of measuring the energy efficiency of windows for a decade or two. It’s that A-E scale that has become familiar on a range of products, not just windows, which tells you what level of energy efficiency that product provides.
But we have a problem. As far as I understand, the energy performance certificates on window products that we have right now are based on windows that do not have trickle vents installed as part of the test. I’m not aware of other factors such as Georgian bars, leading and other decorative glass features are included in testing, but that’s a tangent to go down another day. The issue we’re going to have is that if we end up in a scenario where all window installations in all settings have to have trickle vents then the existing Window Energy Ratings are going to become invalid as testing at the time would not have included it.
So what happens if this becomes reality? Suppliers would face a couple of scenarios as far as I can see. They would have to spend even more time and money on getting their products retested with trickle vents included to be able to issue new, up to date Window Energy Ratings certificates. Or, they would have to find another way to show that their windows can comply with the new Building Regulations and their new lowered u-Values, whilst also including trickle vents. Well, the second option is already available. Companies will already know what u-Values their window can achieve.
If we face a scenario where trickle vents will be made mandatory in all windows in all settings, I cannot see that fabricators are going to be rushing to get their WERs redone. If they can prove their u-Value is compliant, which many systems on the market already are, then that is the route they will go. It would then cause a serious shift towards u-Values more generally as a means of measuring efficiency, which some will argue is the more accurate way to judge energy efficiency in a window or door anyway.
Then consider this in a roadmap of 3-5 years. There are going to be further revisions downwards of u-Values each time Building Regulations are updated. The Government fully intends to bring them down below 1.0 in the medium term. If we don’t end up having to fit all new windows with trickle vents this time around, you can bet your last quid that they’ll get us to do that sooner rather than later. So, every time the goalposts are moved, are companies really going to get all their windows retested each time just to update their WER certificate? No, they won’t. More and more of the industry will revert to the ever-popular u-Value method and use that to prove compliance and make life easy for themselves.
As I see it, Window Energy Ratings and their use may be about to look less embedded.
All that above is totally dependent on how installers are going to be required to comply with the new Building Regulations. That I believe is something that is being worked on now. If there is a way to comply with the new regs without having to install trickle vents in every window then the scenario above is going to be massively tempered and the amount of upheaval is going to be severely limited. But, if methods of compliance are going to compel window installers to fit a trickle vent into everything, then of course what I explore above would be a very possible outcome.
Since these newly revised Building Regulations dropped just before Christmas, I have been having very regular discussions with a number of parties and how their implementation is going to look. What is becoming very clear is that over time the Government really wants to bring u-Values down further and further.
So whilst new minimum u-Values for new windows going into existing dwellings is going to be 1.4, in future revisions we’re going to see that number come down. Some believe we are headed below 1.0, perhaps 0.8 when it comes to new-build, with retrofit work to follow a couple of years after that. Should that be the case, then there is going to have to be some serious innovation in the window market to be able to achieve those sorts of figures.
That is where you’ll see the triple glazing versus vacuum insulated glazing (VIG) debate fire up again. It will of course be a battle of the vested interests in that one. Manufacturers of the products involved would lobby heavily to promote their own solutions as the path forwards. But with the addition of VIG to the market, there is now another way, consuming far less material, to achieve u-Values that are already way ahead of current requirements.
As we start on this path of Building Regulations focusing more on energy efficiency and ventilation, the role u-Values are going to play is going to become more and more central.
To get weekly updates from DGB sent to your inbox, enter your email address in the space below to subscribe:
By subscribing you agree to DGB sending you weekly email updates with all published content on this website, as well as any major updates to the services being run on DGB. Your data is never passed on to third parties or used by external advertising companies. Your data is protected and stored on secure servers run by Fivenines UK Ltd.
Bang on! For the record, Georgian bars, leads are specifically excluded from the testing as are TV’s, that said if TV’s become mandatory, they’ll need to be incorporated. Truth is I suspect Uvalues will become the factor and WER’s, irrelevant. As for debates around double, triple and Vacuum, Vacuum must win on every count (except cost perhaps) because less glass, equal or better performance. That said costs for two spacer bars, twice the Krypton costs make triple units nearly as expensive as Vacuum. One thing is for certain, compliance with the next round of building regulation changes, just got even… Read more »