A Rated Windows Explained

A Rated Windows are windows that have achieved an energy efficiency rating of A from the Window Energy Rating  (WER).

These windows provide enhanced insulation, improved airtightness and better performance compared to other traditional windows.

The A-rated window help reduces energy costs and achieves a higher EPC rating.  

Improve the energy efficiency of your existing windows and your home

Scott James’ team offers professional reglazing services for owners of period properties. Our team can reglaze and refurbish period sash windows.

The Slimline double glazing that we offer is widely accepted for Grade 2 listed properties as it does not have a spacer bar, which is often a cause of refusals.

Using a vacuum as an insulating component, this insulated glazing unit boasts a superb thermal efficiency of 0.48 – 0.7 U-Value, depending on which glazing brand you choose, LandVac or FINEO glass.

By reglazing single glazing in your windows, windows are estimated to achieve “A” efficiency. 

What is U-value for A + windows? 

U-value for windows is the measure of heat transfer through a window and is used to measure the thermal performance of windows and doors.

A Rated Windows typically have a U-value that falls between 0.8 – 1.1 W/m2K, meaning they offer excellent energy efficiency, as well as being more environmentally friendly.

What distinguishes an A from an A+?

A is considered to be the most energy-efficient windows, providing improved insulation and airtightness performance compared to other windows.

A+ Rated Windows, on the other hand, provide even better levels of energy efficiency than A-rated windows, as they have a lower U-value which is typically between 0.7 and 0.8 W/m2K.

As such, A+ rated windows offer the highest level of energy efficiency available in modern window designs. 

Are B-rated windows good enough? 

B Rated Windows are not considered to be as energy efficient as A-rated or A+ rated, but they still offer enhanced insulation and airtightness performance compared to traditional windows.

The U-value of B Rated Windows typically ranges between 1.2 – 1.5 W/m2K. 

How will A Rated windows affect EPC rating? 

“A” rated products, including windows, can significantly improve the energy efficiency rating, or EPC rating, of a building by reducing its heat loss.

As such, A-rated windows are recommended for anyone looking to improve their building’s energy efficiency rating. 

Check out these articles that might be of interest to you:

What is FENSA, and how does it affect you?

Sash windows secondary glazing alternative

Safety glass regulations

Double glazing thickness

Standard window sizes in the UK