Glazing ratings explained

Double glazing itself is pretty self-explanatory and it is something which the majority of us have heard of, but we consider it safe to say that the specific glazing ratings are more of a grey area. If you are one of those who doesn’t quite understand, we have a simple guide for you.

What is

WER is an abbreviated term used for ‘Window Energy Ratings’, and this combines with the U Value create a way of calculating a windows energy efficiency.

What is

U Value is a measurement of the rate of heat transfer through window insulation. It dictates how well glazing prevents heat from escaping. The lower the U Value, the better the glazing is at preventing heat loss or heat gain, in return, making the property more energy efficient.


Typically speaking, the higher the rating, the higher the quality and alongside this, the higher the cost. You can however choose a glazing rating that suits your needs and budget.

  • What are A++, A+ and A Rated windows?

    When it comes to heat retention and overall energy efficiency, these windows are top of the scale. Whilst considered an investment, the windows are guaranteed to provide you with the greatest performance long term.

  • What is a B Rated window?

    B Rated windows are a grade below but are still considered a long term investment. Whilst still providing great insulation and energy efficiency, they are slightly more affordable due to a slight decrease in return of investment.

  • What is a C Rated window?

    If you are looking to upgrade your double glazing on a stricter budget, C Rated windows might be the solution for you. Whilst A Rated is considered the greatest in terms of energy efficiency and return of investment, any A-C grade is considered top to mid-tier, and C Grade glazing still provides a portion of energy-saving benefits.

  • What are D, E and E Rated windows?

    As you can predict, the lower down the chain you go, the less of a return you get from each glazing grade. When it comes to your windows, we would always recommend C Grade or above to ensure you receive a return in heat retention, energy efficiency and overall performance that is worth the cost of a glazing upgrade.

How does a glazing grade

The higher your glazing grade, the lower your property’s U Value will be. In simple terms, this means that your home will be able to retain heat and prevent cold air from entering, resulting in you relying on your central heating less during the colder months, and money being saved on your monthly energy bills.

If you are looking to upgrade the windows of your property, our team of experts at Point of View Glazing can provide you with advice and support, as well as seamless installation services. Get in touch to find out what you can achieve for your property. Give us a call on 020 8611 2917, send us a WhatsApp message on or email us at today.

Do you have a question?

Get in touch with us! We can provide advice and answers to any of your questions. Call us on 020 8611 2917, send us a WhatsApp message on , or email us at

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