You’ll have noticed the little stickers on appliances whenever you’ve gone shopping in an electrical goods store which show a rating from A to G. This is the energy efficiency scale created by the BFRC (British Fenestration Ratings Council). The ratings are also used for windows, and are called ‘WER’ (Window Energy Ratings). As you can imagine, the closer to A the product is, the better for the environment and your energy consumption it is.
A rated windows are more expensive. What’s the cheapest option while still being eco-friendly?
While it would be great if everyone could install durable and efficient A rated windows, sometimes it’s just not possible. It may spoil the aesthetic of your home to choose a particular window, or you may just simply not be able to fit it into your budget.
As long as you use at least a C rated window, you’ll still be able to reduce the amount of energy you use. By using a window with a rating of C or above, it’s possible to reduce the amount of energy lost by up to 90%, although any reduction is a step in the right direction.
If you’re in a position to install A rated windows, you could save around £130 a year on your energy bills. Consequently you’ll be able to enjoy a pleasant room temperature without having to turn up the thermostat. This also means that the amount of carbon dioxide being emitted by your home is reduced and your personal contribution to global warming is much less severe than it used to be. On top of that, your own personal home environment will be greatly improved in terms of the amount of noise that’s cut out.
What constitutes an A rated window?
On any double glazed window which is basically efficient, a low-emissivity transparent coating is coated directly onto the glass to prevent too much heat from escaping and too much cold from getting in. And you may think that it’s air inside the gap between the two panes of glass, but it’s actually a low conducting gas, most commonly argon. Both factors contribute to the window having a lower U value (the way that energy efficiency is measured in windows). The lower this figure is, the better, and today’s double glazing manages about 1.6. This figure used to be closer to 3 when double glazing first came about.
The main factors that will give a window an A rating are:
- A thicker cavity between the two layers of glass
- A lower conducting gas in the cavity
- Energy efficient materials used for the frame and components of the window, such as high quality uPVC
As with anything that has a high BFRC rating, A rated windows will pay for themselves in the long run and you’ll enjoy dramatically reduced energy bills as long as the rest of your home is also reasonably energy efficient. But don’t worry if you find that buying a product with an A rating is too expensive – a C rating should be sufficient enough for you to start reducing your carbon footprint.
Image: Acuatro Arquitectos