When installing new windows and doors in their home or business, many property owners know to look for things like ‘energy efficiency’ in the specs and low u-values for the glazing. But when it comes to looking at the coloured rainbow labels for energy ratings, what do they actually show you? Here’s our guide to make things clearer.

Comparing energy efficient windows & doors? Expert tips for reading the coloured traffic light scheme for energy rating labels. We cover how to read the labels, energy ratings, how to find energy efficient windows & more.

What Are Energy Rating Labels?

If you haven’t seen them before, energy rating labels are the small colour charts attached to windows which have a lettered system and are similar to those that come with other products in your home such your refrigerator or light bulbs. The purpose of the label is to show users more clearly how their products are rated on the spectrum, and it’s a great way to compare products to see how much energy they use when they’re operating. There are several bodies that operate energy rating schemes for windows, including CERTASS, the BFRC (British Fenestration Rating Council) and the BSI (British Standards Institute), but they all work in the same way.

Energy Ratings Explained

The ratings of your windows are defined by a letter which is assigned to a product based on its whole performance. Areas that are considered include the window frames (their design and material used), glazing, solar gain, air leakage and thermal efficiency. These are all factors which may determine how well the windows prevent heat escaping from your home, as well as how much UV light can enter. The products with the best ratings will offer you the most potential savings, reducing how much you have to spend on keeping your home warm.

How to Read the Labels

The best ratings are A and A+ rated, and this decreases along the scale. So, a C rated product is less energy efficient than an A Rated product, for example. To remain UK Building Regulations compliant, windows must have a minimum rating of Band C. The traffic light system used will highlight exactly where your windows fall on the spectrum. Other information the label may show (depending on the scheme used) includes the date the rating was awarded, the climate zone (e.g., UK), the product’s efficiency rating and specific breakdowns of the score such as thermal transmittance, solar factor and effective air leakage.

Get Energy Efficient Windows & Doors

Here at Hamiltons, all of the high quality windows and doors we supply and install are A and A+ rated, helping homes to remain as energy efficient as possible. We work across South London and Surrey, offering extensive window and door collections to homes and businesses in locations such as Addlestone, Cobham, Dorking and Farnham. Our highly experienced window experts are happy to talk through any of the products we provide, including their energy efficiency ratings and other features. Call our specialists now on 020 8390 4855 for advice.