Installing energy-efficient windows in your home will reduce heat loss and save you money on your monthly bills. Window Energy Ratings (WER) are the best way to establish how energy-efficient a window is, grading its performance from E to A++.
In October 2010, legislation was written demanding windows to have a minimum WER of band C. But for a truly energy-efficient build, it needs to be much higher.
Types of Energy Performance Ratings for Windows
When your new windows arrive, they will have a sticker featuring a rainbow tier scale. This is the official rating chart which indicates the window’s energy rating, and can be provided by a number of registered bodies whose job it is to audit window suppliers.
WERs were first introduced back in 2004 by the British Fenestration Rating Council (BFRC), an independent body supported by the UK government to distribute energy performance ratings across the country. In the last few years, other bodies have been introduced into the fold, such as Certass and BSI.
How Windows Are Rated
When registered bodies such as the BFRC rate windows, there are three distinct factors that they will look at to determine the product’s final certification.
- U-values: Which measure how much heat is lost through thermal transference.
- L-values: Which measure air leakage around the window frame.
- G-values: Which measure the amount of heat lost through the glass.
Once these values are established and rated in accordance with set industry standards, the final grade will be determined. The official WER will fall between A++ and C.
A-Ratings Explained
Windows rated between A and A++ are among the best performing. A-rated windows are generally slightly more expensive than, say, a C-rated model – this is due to the quality of the materials used to make it, extra sealant around the frame, better glazing, and so on.
As it goes, the more you spend on your windows (and the higher the WER) the more you will save in the long run on your energy bills. So, although it is a larger initial spend, in time, it will pay for itself.
B-Ratings Explained
Speaking of investment gain, B-rated windows have most of the energy-efficient benefits of A-rated windows, but there is a notable difference in how efficient they are in comparison. This slight dip in performance does mean B-rated windows are cheaper than A-rated ones.
If you are a money-conscious homeowner, or perhaps lacking in disposable income currently, you may want to opt for this more affordable option, whilst retaining some of the key energy-saving benefits.
C-Ratings Explained
C-rated windows are the set industry standard, as of 2010, so all new windows purchased from reputable manufacturers will have this WER. C-rated windows are ideal for homeowners with smaller budgets but who still want to reduce their energy costs.
You can increase the energy efficiency of your C-rated windows by upgrading to double or triple glazing. This can be done before your purchase or after, as secondary glazing.
Are C-Rated Windows Energy-Efficient?
For a window to be deemed energy-efficient, as an industry standard, it needs to be rated A or higher. A C-rated window is a minimum standard across the country, so no windows purchased new from a reputable supplier will be lower than that.
Standard aluminium windows can achieve an A+ rating, but if you want the highest rating possible you should opt for frames made of unplasticised polyvinyl chloride, or ‘uPVC’.
At South Coast Home Improvements, we specialise in A++-rated uPVC windows. This is because of its versatility, its need for minimal maintenance, and above all, how well it seals homes against unwanted heat loss – far better than any metal or timber alternatives.
The Most Energy-Efficient Windows for Your Home
When purchasing new replacement windows for your home, it is important to have an awareness of the energy rating and overall performance of the product you are buying. This consideration will not only save you money on your monthly living expenses, but will also help us to reduce our country-wide carbon emissions and move into a more eco-conscious future.
