Quality windows: myths and reality

We are often confronted with tricks, misleading claims and exaggerations when purchasing different products. Advertising is the engine of commerce, and some businesses use questionable methods to attract customers. Inventing non-existent technical specifications or giving too much importance to features that do not play a significant role are methods that can sometimes be found in a highly competitive market.

But if you know what is myth and what is reality, it becomes much easier to make the right choice. Many articles are now available explaining the production and construction of uPVC windows, so it is becoming increasingly difficult for unscrupulous manufacturers to mislead their customers. One of the most important things for any window company is its reputation, built through honest and transparent operation.

A reputable company should be able to provide relevant information about its products and demonstrate that its windows meet applicable technical standards. This is one of the basic things to consider when choosing new windows. If a company cannot clearly explain what it is supplying or provide the necessary product information, it is worth asking more questions before making a decision.

Rather than judging a window by one specification or marketing claim, it is more useful to consider the complete system. Our guide to what makes one window better than another explains how the frame, glazing, seals, hardware, manufacturing and installation work together to determine the quality of the finished window.

What deceptions are there in the window industry?

There are a number of myths about window specifications. One concerns the thickness of the glass and its influence on thermal and acoustic performance. Glass thickness can affect strength and acoustic performance, but thicker glass alone does not automatically make a window significantly more energy-efficient or soundproof. Acoustic performance depends on the complete glazing configuration, including factors such as glass thickness, the use of different glass thicknesses, laminated glass and the space between the panes.

Thus, soundproof glazing and simply using thicker glass are not the same thing. Choosing the right glass for noise reduction is more important than simply looking for the thickest available glass.

The next common misunderstanding is that the maximum thickness of the profile automatically prevents heat loss. In other words, a wider profile is sometimes presented as sufficient to make a window highly energy-efficient and prevent heat leakage. This is also incorrect. Profile design is only one part of the window’s thermal performance; the glazing, seals, construction of the frame and correct installation are also important.

The myth that uPVC itself is harmful is also very common. Quality uPVC window profiles are manufactured from materials designed for their intended application. The more useful question for a buyer is whether the window system comes from a reputable manufacturer, complies with the relevant requirements and is manufactured using appropriate materials and processes.

A quality window company uses appropriate equipment and manufacturing processes to turn the profile, glazing, seals and hardware into a strong, stable and durable finished window.

Another misunderstanding concerns the space between the panes of an insulated glazing unit. Air and inert gases such as argon do not have exactly the same thermal properties. Argon is commonly used to improve the thermal performance of an insulated glazing unit. However, it should not be described as the main source of a window’s sound insulation. Acoustic performance depends primarily on the complete glazing configuration and the performance of the entire window system.

Double or triple glazing?

Double glazing is a suitable option for many homes and can provide a high level of thermal comfort, noise reduction and overall performance when the complete window is properly specified. Its performance depends not only on having two panes of glass, but also on other components, including:

• Elastic and resilient gaskets running around the window to provide an effective seal.
• A high-quality profile system.
• Appropriate glass and coatings where required.
• The insulated space between the panes, which may use a gas such as argon.
• Quality manufacturing and assembly.

Triple glazing uses three panes instead of two and can provide improved thermal performance in an appropriately designed window system. However, it is generally heavier and more expensive than double glazing, and the additional performance may not be necessary for every property.

Therefore, it is not correct to say that triple glazing is always better or more reliable simply because it contains an additional pane of glass. The choice between double glazed windows and triple glazed windows should depend on the requirements of the property, the window system and the performance the homeowner wants to achieve.

Is it a problem to install double glazed yourself?

It is recommended that replacement windows are installed by experienced professionals. Installation involves much more than simply placing the new window into the opening. The window needs to be correctly positioned, fixed, sealed, adjusted and finished.

There are many installation manuals and videos available online, but they cannot replace practical experience. Conditions can also vary considerably from one existing window opening to another, particularly during replacement projects.

Installing a window is a step-by-step process where experience is important. Even a high-quality window can be affected by poor installation, so professional installation helps ensure that the finished window performs as intended.

This is why installation is an important part of window quality rather than a separate detail to think about only after the window has been purchased.