BFRC is the UK’s most trusted and widely used rating council for energy performance in windows and doors. Our 'rainbow' labels are visible proof of invisible performance, showing your product has been independently verified by experts to perform as promised.

BFRC rainbow labels use coloured bars to clearly indicate the energy efficiency rating of windows and doors from A++ to E. They are similar to the energy efficiency labels found on fridges, washing machines, and other household products.

BFRC energy ratings allow you to compare similar window and door products and choose the most suitable for your home.

Learn more about BFRC energy ratings

When replacing windows and doors, you need more than unsubstantiated claims about energy efficiency; you need complete and impartial proof.

By asking for a BFRC rated product, you are making sure the energy efficiency of the whole window or door system you are buying has been independently tested to determine how well it keeps heat in (U-value), the amount of energy available from the sun (G-value), and the amount of air leakage (L-value).

Only when you know all three values can you be sure about its complete balance of energy performance.

Find BFRC rated products

BFRC was founded to provide scientific and independent proof of energy performance in windows and doors. We have since grown to become the industry’s most trusted ratings council with the most widely used energy performance rating system.

Our “rainbow” ratings were the first of their kind. They confirm products have been independently assessed by experts in building physics for heat loss, solar gain, and air leakage, and the whole system has been verified to perform as rated.

Manufacturers of BFRC rated products are regularly audited to ensure the BFRC ratings for their windows and doors remain up-to-date.

Find BFRC Approved Manufacturers and Installers

A BFRC Approved Installer is a company that has applied to, and been accepted by, the BFRC to join its list of installers who recommend and install BFRC rated windows and doors.

You can find BFRC Approved Installers in your area by using our online search tool.

You could save money on your heating bills by installing energy efficient windows and doors. The greater their energy efficiency performance, the more you could save.

Reducing how long and often you heat or cool your house can also help to reduce your carbon footprint. The best way to ensure you’re saving the most with your windows and doors is to ensure they are fitted by a BFRC Approved installer.

They will use BFRC rated doors and windows throughout the whole system. Specific savings will of course vary from property to property.

Triple glazing can be used to produce very thermally efficient windows and doors and is typically used in A++ ratings. However it is important to remember that in addition to the thermal performance (U-values), our energy ratings also take into account the positive effect of solar gain (free energy from the sun).

The additional pane of glass in a triple glazed unit can significantly reduce solar gain and result in a lower energy rating. So depending on the glass types used, it is possible for double glazed units to achieve the same energy ratings as triple glazed ones.

This means triple glazing isn't necessarily 'better' than double glazing when it comes to BFRC energy ratings. Windows with triple glazed units can give lower glass (centre pane) U-values, however this is very much dependent upon the types of glass used. Typically the additional third pane of glass will reduce the solar gain significantly. It is possible to achieve the BFRC A+ rating using double glazed windows.

The energy rating calculation takes all components of the window or door into account.

There is no direct correlation between u value and energy rating. It is possible to achieve an A rating with u values ranging from 1.0 W/m2K through to 1.7 W/m2K as the solar gain and air leakage needs to be taken into account.