What Does the U-Value of a Window or Door Mean?

07th November 2023

If you've been looking into buying a new set of windows or doors, you've probably come across the term 'U-value' at some point. It's a common phrase, but what it actually means isn't that clear.

Put simply, the U-value of a window or door tells you how much heat it allows to escape. The lower the U-value, the better it is at keeping your space insulated, and the more energy-efficient it is as a whole.

While the U-value is just one piece of the puzzle when you're shopping for a new window or door, it's an important one. Keep reading to find out everything you need to know about U-values, from what they are to why they matter!

What Are U-Values?

U-values are a measurement of how well a building material handles heat transfer. A lower U-value means the material is better at keeping your space warm by reducing heat loss.

U-values are typically measured in units of watts per square metre per degree Celsius (W/m²·°C). This might sound a bit confusing, but it simply refers to the amount of heat energy that can pass through one square metre of a material for every 1-degree temperature difference between the inside and outside of the building.

Manufacturers calculate the U-value of their windows and doors by determining the thermal resistance (R-value) of each component, such as the frame, glazing, and any spacers or gas fills between glazing layers. They then add up all the R-values and take the reciprocal of the sum, resulting in the U-value.

Why Do Some Windows and Doors Have Lower U-Values Than Others?

Different materials and construction techniques can bring about variations in U-values. Energy-efficient windows and doors often come equipped with features like double or triple glazing, low-emissivity (low-E) coatings, and insulating frames to reduce heat transfer.

Why Does the U-Value of a Window or Door Matter?

Skyhigh energy prices have made having an energy-efficient home more important than ever. A well-insulated house will trap heat during winter and keep it out during summer, so you spend less on heating and cooling it. It will also help you cut down on your use of fossil fuels, which in turn decreases your carbon footprint.

This is why U-values matter so much. When you pair low U-value windows and doors with well-insulated walls and roofs, you can make a real difference in your home's energy efficiency. You'll not only save money on heating bills every year, but also play your part in reducing your carbon footprint in the long run!

Energy-Efficient Windows and Doors, Made Bespoke for Your Project

Now that you've gained a better understanding of what U-values are and why they matter, you're ready for the next step: choosing the perfect energy-efficient windows or doors for your property!

Alimax is Dorset and Hampshire's leading manufacturer of aluminium windows and doors for trade customers. When you choose us as your supplier, you get access to a whole host of benefits:

• All of our products achieve an energy rating of B or above with market-leading U-values. Their excellent thermal efficiency will help reduce energy bills and carbon emissions.
• Our high-quality aluminium frames are custom designed to fit each property, guaranteeing a stunning finish.
• Advanced weatherproofing and security features will keep homes safe and warm for years to come.
• Lead times start from as little as 10 days.
• Windows and doors up to 7 x 3 m come fully assembled for ease of installation.

When you're in need of top-quality aluminium windows and doors, look no further than Alimax. Get a quote online or call us on 01425 205465 to get started today!