Energy Ratings for UPVC Windows


UPVC windows have become a popular choice for homeowners. They are known for their durability and low maintenance. But, there’s more to these windows than just longevity. 

Energy efficiency plays a crucial role in modern buildings. The energy ratings for UPVC windows are key in this context. These ratings determine how well the windows retain heat and save energy. Higher ratings indicate better insulation, helping reduce energy bills and environmental impact.

Understanding these ratings can help homeowners make informed decisions. They can choose windows that enhance their home’s insulation, reduce energy bills, and lower carbon footprints. Let’s get into what these energy ratings mean and why they matter.

Understanding Energy Ratings for UPVC Windows: A Comprehensive Guide

Dive into energy efficiency with our comprehensive guide to understanding energy ratings for UPVC windows. Learn how U-values, solar heat gain, and more contribute to performance. Make informed choices to enhance your home’s energy efficiency. Explore the key factors that matter!

Basics of Window Energy Rating

The Window Energy Rating (WER) is a system used to measure and communicate the energy efficiency of windows. The rating is designed to help consumers make informed choices about the energy performance of windows when replacing or installing new ones in their homes. 

The Window Energy Rating is part of the British Fenestration Rating Council (BFRC) scheme. It is the UK’s nationally recognized system for rating the energy efficiency of windows and doors.

Key components of the Window Energy Rating include- 

  • U-Value: This measures the rate of heat loss through the window. A lower U-value indicates better insulation and energy efficiency. The U-value is expressed in W/m²K (watts per square meter kelvin).
  • Solar Heat Gain: This measures the ability of the window to capture and utilize solar energy. It is expressed as a percentage, and a higher solar heat gain is beneficial in colder climates, as it helps to increase the warmth within a building.
  • Air Leakage: This factor indicates how much air can pass through the window. The lower the air leakage, the better the window prevents drafts.
  • Visible Transmittance (VT): This measures the visible light that passes through the window. A higher VT indicates more natural light entering the building.

The Window Energy Rating is presented on a scale from A++ to G, with A++ being the most energy-efficient and G being the least. Consumers can use this rating to compare the energy performance of different windows and choose products that align with their energy efficiency preferences and requirements.

It’s important to note that building regulations in the UK may require a minimum Window Energy Rating for new or replacement windows. So it’s advisable to check these regulations when considering window installations. Additionally, energy-efficient windows not only contribute to reducing energy bills but also help in minimizing the environmental impact of a building.

Things You Can Do To Improve Your Window’s Energy Efficiency

Improving your window’s energy efficiency can lead to cost savings and a more comfortable home. Here are several strategies- 

1. Upgrade to Energy-Efficient Windows

Choose windows with high Window Energy Ratings (WER) to ensure optimal energy performance. Look for reputable manufacturers that offer products designed to meet or exceed industry standards.

2. Install Double or Triple Glazing

Multiple layers of glass with sealed air spaces or gas-filled gaps between them reduce heat transfer. This design enhances insulation, making it more difficult for heat to escape or enter your home.

3. Use Low-E Glass

Low-emissivity (Low-E) coatings on glass surfaces minimize heat loss by reflecting radiant heat into the interior. This technology allows natural light to enter while maintaining a comfortable indoor temperature.

4. Consider Gas-Filled Panes

Argon or krypton gas is often injected between window panes, displacing the air. These gases are denser than air, reducing convective heat transfer and enhancing the window’s insulating properties.

5. Optimize Window Frames

Choose window frames made from materials with good thermal properties, such as UPVC, wood, or aluminum with thermal breaks. These materials help minimize heat transfer and improve overall energy efficiency.

6. Use Window Treatments

Thermal curtains or blinds create an additional barrier, trapping air near the window and reducing heat loss. During the summer, these treatments can also block sunlight, reducing the need for cooling.

7. Seal Gaps and Cracks

Apply weatherstripping around window frames to seal any gaps and prevent drafts. This simple and cost-effective measure helps maintain a consistent indoor temperature and reduces the workload on heating and cooling systems.

8. Install Storm Windows

Storm windows provide an extra layer of insulation, reducing air movement and heat transfer. They are particularly beneficial in harsh weather conditions and can enhance the overall efficiency of existing windows.

9. Manage Solar Heat Gain

Strategically plant trees or use external shading devices to control the amount of sunlight entering your home. This helps regulate indoor temperatures and can reduce the need for excessive cooling during warmer months.

10. Regular Maintenance

Keep windows in good condition by addressing issues promptly. Repair seals, fix leaks, and replace damaged components to ensure that windows perform at their best.


1. Can UPVC Windows with higher Energy Ratings help reduce energy bills?

Yes, UPVC Windows with higher Energy Ratings are more energy-efficient, contributing to reduced energy consumption. By minimizing heat loss and optimizing solar heat gain, these windows can lead to lower heating and cooling costs over time.

2. Do Energy Ratings for UPVC Windows vary by region or climate?

Yes, Energy Ratings for UPVC Windows can be influenced by regional climate conditions. Factors like temperature, sunlight exposure, and prevailing weather patterns may impact the ideal specifications for windows. It’s advisable to consider regional climate requirements when selecting energy-efficient UPVC Windows.

3. Can existing windows be upgraded to improve their Energy Ratings with UPVC alternatives?

In some cases, existing windows can be upgraded by retrofitting them with UPVC alternatives or adding supplementary features. However, the effectiveness of such upgrades depends on the specific characteristics of the windows and the desired energy performance. Consult with a professional to assess the feasibility of upgrading existing windows for improved Energy Ratings.

Read More:


Understanding Energy Ratings for UPVC Windows is paramount for homeowners of Chesterfield seeking energy-efficient solutions. These ratings, encompassing factors like U-values and solar heat gain, guide informed decisions to enhance insulation and reduce energy consumption. 

Opting for UPVC Windows with higher ratings not only contributes to cost savings but also aligns with environmental sustainability, minimizing carbon footprints. 

The investment in UPVC options with favorable Energy Ratings proves instrumental in creating a comfortable, eco-friendly living space for the long term.

Director at Chesterfield Window Centre | Website | + posts

In 2005, I founded Chesterfield Window Centre with a vision to redefine the window and door industry through a commitment to quality, innovation, and customer satisfaction. The journey began with a deep understanding of the market, identifying gaps, and envisioning a business that not only meets but exceeds customer expectations.

Scroll to Top