Top Tips for Choosing UPVC Windows

If you’re thinking about investing in new or replacement uPVC windows, it’s important to shop around and do plenty of research before you take the plunge. Luckily, there are a few things you can look for to help you determine the quality of any uPVC windows you’re thinking of purchasing.

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Window frames

When choosing a window frame, there are a few things that are important to look out for that indicate good quality. Firstly, you will want your window frames to be chambered. The more chambers a window frame has, the more energy-efficient it will be.

You should also ensure your window has welded joints.

Unlike mechanical joints, these prevent gaps from forming when the window expands or contracts due to hot or cold weather. Weather seals are another important feature to carefully inspect.

Check that the rubber seals around the glass do not have any gaps in the corners of the frame, and check that the window frame also has brush seals, as this help to prevent air or water from penetrating the window.

Glass thickness

Another thing to pay attention to when buying your uPVC windows is the thickness of the glass. There are many types of glass, such as normal float glass and laminated toughened glass.

Your windows should be at least single glazed (6mm thick), but double glazing (two 6mm glass layers with a gas layer in-between) or triple glazing (three 4mm glass layers with two gas layers in-between) are even better for extra security and energy efficiency.


A useful metric to help determine your uPVC window’s energy efficiency is its Window Energy Rating (WER).

Windows are ranked from A to G, with A++ being the most efficient and G being the least efficient. Since 2010, building regulations in the UK have required all newly installed windows to have a rating of at least C.

More energy-efficient windows are likely to be more expensive but may turn out to be a worthwhile investment due to the money you will save on your heating bills.


It’s vital that your windows provide security and do not have any vulnerabilities. To help ensure security, uPVC windows should have a concealed locking system.

The hardware should also be made using type 304 stainless steel as this prevents the hinges, friction stays and handles from rusting and corroding over time.

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Lengthy Warranty

Before you make any purchase decisions, it’s absolutely vital that you check your installer’s warranty policy.

This not only gives you a clue as to the quality of the product, (retailers only offer long guarantees if they are genuinely confident in their product) but will give you peace of mind that you can get your windows repaired or refunded if any kind of manufacturer or installation fault becomes apparent.

Ideally, you want a warranty of at least 10 years for your uPVC windows. Be wary of warranties shorter than this, as they could suggest poor quality and will mean you will have less time to report any faults that may appear.

TIP: Also read about Steel Window Replacement