What is an A-rated window?

Windows with diamond leading

Most people know that fitting new double glazing will make their homes warmer. But what difference does it really make? If you’ve bought a fridge or washing machine, you’ll recognise the rainbow colour chart. For windows, these are called Window Energy Ratings (WERs).

If you’re shopping for new windows and doors in the East Midlands, this is what to look for.

What are Window Energy Ratings (WERs)?

Independently verified by organisations like the BFRC (British Fenestration Ratings Council) and CERTASS Window Energy Ratings use the A+ — G energy ratings ‘rainbow’ sticker, just like the ones you find on home appliances like fridges and washing machines.

As you’ve probably guessed, A+ is the top rating and G is the bottom. Since 2010, in order to comply with Part L of the building regulations, new and replacement windows being installed must have a minimum Window Energy Rating of ‘C’.

Window Energy Ratings came about to make it easier for homeowners to see which windows have the right energy efficiency levels for them, without relying solely on U-value measurements, which don’t reflect the true efficiency of the window as a whole.

Who gets Window Energy Ratings?

WER labels are only given to products which have been certified by third party approved testing to meet the required specifications. If a glazing product doesn’t have a WER label, it doesn’t necessarily mean that it’s not thermally efficient – but it does mean that it hasn’t been tested by an independent third party.

The WER ratings make it quick and easy to choose the right energy rating label for your double or triple glazing. The rating is measured by looking at the whole window: the frame material and design, the type of glass used and the other components that make up the window. They also take into account solar gain, the amount of heat coming through from the sunshine, and air leakage of the window.

What is a U-value for windows?

Sometimes energy efficiency is talked about in U values. They are a measure of how effective building materials are as insulators and how good they are at stopping heat from transmitting into and out of a building.

However, they don’t take into account thermal gain to measure how energy efficient the window is, so Window Energy Ratings were created to make it easier for homeowners.

Save Money with Energy Efficient Windows

Well fitted, energy efficient windows can save you money on heating and lighting your home.

Savings can be as much as £155 per year if you’re switching from single glazing to double glazing on an average home. To find out how much you could save on your household bills, take a look at the Energy Saving Trust.

If you’d like to know more about energy efficient windows, or would like a quote to replace your double glazing, come and have a stroll down Trade Street, on London Road in Derby or give us a call on 01332 755551.