Energy Efficiency

Conserving energy in our homes helps to reduce energy bills and protect the environment by cutting carbon dioxide emissions. But how much of an impact does our choice of windows actually make? We answer some commonly asked questions below. 

Do new windows help with energy efficiency?

Yes! Around 20% of the heat escaping from an average house goes out through its windows. This means that choosing the right combination of glazing and window frames is essential to improve the energy performance of your home. 

There are three key factors in determining the energy efficiency of windows:

  1. Thermal losses – heat going out through the window (negative)
  2. Air losses – air escaping between the window and frame (negative)
  3. Solar gain – heat coming in through the windows from the sun (positive)

The energy performance of a window depends on how well it can stop heat from passing through, how little air can leak around the window, and how much sunlight travels through the glass.

Do new windows reduce energy bills?

Yes. The Energy Saving Trust has worked out that you could save around £95 per year on your energy bills by replacing single glazing with A-rated double glazed windows (based on an average UK semi-detached property). You’d also save over 300kg of carbon dioxide!

What type of windows are most energy efficient?

The British Fenestration Rating Council (BFRC) provides an independent rating system for new windows based on their energy performance. Products are rated on a scale from A++ (most energy efficient) to E (least energy efficient). 

Building regulations stipulate that replacement windows must be rated C or above and doors E or higher, except in historic properties and conservation areas.

Replacing your windows with any grade that is higher than you currently have will help to reduce your energy costs and make your home more comfortable. However, windows and doors with ratings A to A++ are the only ratings considered to be energy positive – meaning they absorb more energy than they lose.

For more information on BFRC ratings visit 

Energy Efficiency at CR Windows

We are a licensed member of the BFRC for the manufacture and installation of windows and doors. As we manufacture all of our products on site, we have complete control over the quality of materials used. All of our windows and doors can be designed to achieve any of the BFRC’s ratings, depending on your needs and budget.

Our multi-chambered frame designs deliver exceptional energy efficiency for both windows and doors. These slim frames also allow the area of glass in windows to be optimised, maximising the amount of natural light within your home.

We are always happy to answer any questions you may have about the energy efficiency of our products and installation processes. Our windows and doors can ensure that your home is kept warm and comfortable all year round, while reducing your energy consumption and carbon footprint. 

View our range of BFRC approved windows.

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