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May '25
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Evaluating Energy Efficiency
Window Energy Ratings are a measure of the energy efficiency of windows and are used to help consumers make informed decisions about the energy performance of windows for their homes.
The Window Energy Rating (WER) system was introduced in the UK in 2004. It was developed by the British Fenestration Rating Council (BFRC) and is now widely used to provide information on the energy efficiency of windows and doors. The rating is typically displayed on a label attached to the window, and it takes into account factors such as heat loss, solar gain, and air leakage.
The WER scale ranges from A++ (most efficient) to G (least efficient). Consumers can use this rating to compare different windows and choose products that contribute to better energy efficiency in their homes. This initiative is part of broader efforts to improve the energy performance of buildings and reduce overall energy consumption.
Evaluating Energy Efficiency
Window Energy Ratings are a measure of the energy efficiency of windows and are used to help consumers make informed decisions about the energy performance of windows for their homes.
The Window Energy Rating (WER) system was introduced in the UK in 2004. It was developed by the British Fenestration Rating Council (BFRC) and is now widely used to provide information on the energy efficiency of windows and doors. The rating is typically displayed on a label attached to the window, and it takes into account factors such as heat loss, solar gain, and air leakage.
The WER scale ranges from A++ (most efficient) to G (least efficient). Consumers can use this rating to compare different windows and choose products that contribute to better energy efficiency in their homes. This initiative is part of broader efforts to improve the energy performance of buildings and reduce overall energy consumption.
High Performance Glass
Thermally Efficient Glazing
Sternfenster supplies thermally efficient double and triple glazed units manufactured with revolutionary high performance low-E glass. This glass has been optimised for Window Energy Ratings (WER), giving a highly energy efficient window.
Superior Manufacturing
Wide Applications
Our double and triple glazed units are manufactured to the highest standards, and are widely used in all types of applications, from standard casement windows, to bi-folding doors and conservatories. With Sternfenster, our products exceed and offer the best energy ratings for UK properties.
Low U-Values
Heat & Sound Insulation
Our standard double glazed units achieve a centre pane U-value of 1.2 W/m²K, with a window overall u-value of 1.4 W/m²K. For even higher energy efficient windows and noise insulation, we are also able to offer a range of triple glazed units with a u-value of 0.6 W/m²K (window overall u-value 1.0 W/m²K).
efficient
High Performance Glass
Thermally Efficient Glazing
Sternfenster supplies thermally efficient double and triple glazed units manufactured with revolutionary high performance low-E glass. This glass has been optimised for Window Energy Ratings (WER), giving a highly energy efficient window.
Superior Manufacturing
Wide Applications
Our double and triple glazed units are manufactured to the highest standards, and are widely used in all types of applications, from standard casement windows, to bi-folding doors and conservatories. With Sternfenster, our products exceed and offer the best energy ratings for UK properties.
Low U-Values
Heat & Sound Insulation
Our standard double glazed units achieve a centre pane U-value of 1.2 W/m²K, with a window overall u-value of 1.4 W/m²K. For even higher energy efficient windows and noise insulation, we are also able to offer a range of triple glazed units with a u-value of 0.6 W/m²K (window overall u-value 1.0 W/m²K).
efficient
Importance of Energy Ratings
Windows are significant contributors to energy loss in homes and buildings. Poorly insulated windows can result in heat transfer, causing increased energy consumption for heating and more money spent on heating bills. A higher WER indicates better energy efficiency, meaning the window can help keep the interior temperature stable, reducing the need for central heating or air conditioning.
Importance of Energy Ratings
Windows are significant contributors to energy loss in homes and buildings. A higher WER indicates better energy efficiency, meaning the window can help keep the interior temperature stable, reducing the need for central heating or air conditioning.
Start supplying energy efficient windows and doors from a multi award winning manufacturer today.
Frequently Asked Questions
What is a good window energy rating?
The highest energy rating a window can receive is A++, ranging down to G. Ratings are primarily calculated based on the U, G and L values that the window achieve. This covers the thermal performance, solar gain and air leakage performance of the window. All of these are considered when calculating the overall WER rating. We manufacture quality windows that consider all of these performance elements ahead of testing.
What affects a WER rating?
WER takes the following factors into account when ranking on a scale from A++ – G:
Glazing: The number of glass layers (single, double, or triple glazing) and any coatings applied to the glass can affect the window’s energy performance.
U-Value: This measures the rate of heat transfer through the window. The lower the U-value, the better the insulation and amount heat is lost through the double glazing
Solar Heat Gain: This measures how well the window holds solar energy. A higher solar heat gain value indicates better solar heat retention, which can be better in colder conditions.
Air Leakage: This assesses how much air can pass through the window.
Warm Edge Spacers: These are insulating components that separate the glass panes in double or triple-glazed windows. The type of spacer used can impact the overall energy efficiency of the window. See how we build super spacer technology into our casement windows at Sternfenster.
Frame Material: The material used for the window frame affects its insulative properties- we use energy efficient uPVC and aluminium at Sternfenster with our manufacturing.
Window Size: Larger windows generally have a larger impact on energy efficiency due to their greater surface area for heat transfer.
How fast are your lead times?
We offer exceptionally fast lead times as low as five days, without compromising on quality. Contact us today to find out more on our glass enhancements.
Does Sternfenster offer any warranties for their products?
We offer competitive warranties, lead times as fast as five days and outstanding aftercare.
Frequently Asked Questions
What is a good WER rating?
The highest energy rating a window can receive is A++, ranging down to G. Ratings are primarily calculated based on the U, G and L values that the window achieve. This covers the thermal performance, solar gain and air leakage performance of the window. All of these are considered when calculating the overall WER rating. We manufacture quality windows that consider all of these performance elements ahead of testing.
What affects a WER rating?
WER takes the following factors into account when ranking on a scale from A+ – G: Glazing, U-Value, Solar Heat Gain, Air Leakage, Warm Edge Spacer Bars, Frame Material and Window Size.
How fast are your lead times?
We offer exceptionally fast lead times as low as five days, without compromising on quality. Contact us today to find out more on our glass enhancements.
Does Sternfenster offer any warranties for their products?
We offer competitive warranties, lead times as fast as five days and outstanding aftercare.
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