Made to Measure Secondary Glazing

When homeowners want to reduce noise in their property, the first assumption is often that replacing existing windows with new double or triple-glazing is the only solution. However, this is not always the most effective or practical approach, especially for homes with single-glazed windows, period properties, or listed buildings. In many cases, made-to-measure secondary glazing delivers significantly better noise reduction, thermal efficiency, and comfort without disturbing the original window.

Secondary glazing has become one of the most effective and affordable solutions for tackling noise pollution, improving insulation, and enhancing everyday living conditions. Designed to work alongside your existing window, a high-quality secondary glazing system can dramatically transform your home while preserving its character.

What Is Secondary Glazing?

Secondary glazing involves installing a discreet internal window behind your original window. This secondary glazing window is independent of the existing window frame and is fitted on the room side, either into the window reveal or directly onto the internal face of the window frames.

Unlike replacement glazing units, secondary glazing does not require removing or altering the original window. This makes it particularly suitable for homes with heritage features, conservation requirements, or fragile single-glazed windows that homeowners wish to retain.

Each secondary glazing panel is made to measure, ensuring a precise fit and maximum performance. Modern glazing panels are slim, unobtrusive, and designed to blend seamlessly with your interior décor.

Why Replacing Windows Isn’t Always the Best Solution

While replacing old windows with modern double glazing can improve energy efficiency, it is not always effective at reducing external noise. Sound travels differently from heat, and simply upgrading glazing units does not guarantee a noticeable reduction in noise intrusion.

In fact, well-installed secondary glazing is often more effective at reducing noise than replacement windows because it introduces a separate internal barrier and a crucial air gap between the original window and the secondary glazing panel. This air cavity plays a key role in disrupting sound waves before they enter your living space.

For homeowners concerned about costs, secondary glazing is typically much lower than a full window replacement, making it an attractive and practical alternative.

How Secondary Glazing Reduces Noise
External noise enters most homes through closed windows, even when they appear well-sealed. Traffic, aircraft, trains, industrial activity, and noisy neighbours can all significantly impact quality of life, leading to stress, fatigue, and disrupted sleep.

Secondary glazing is highly effective at reducing unwanted sound because it creates multiple layers of protection:

• A second pane of acoustic glass
• A sealed frame that prevents air gaps
• A wide air cavity between the glazing panels

When installed correctly, secondary glazing can reduce noise levels by up to 54 dB—up to 97%—creating a calm, comfortable indoor environment. While no solution can fully soundproof a home, secondary glazing is among the most effective noise-reduction methods for residential properties.

The Importance of the Air Gap

One key factor in achieving high performance is the distance between the original window and the secondary glazing window. An air gap of approximately 150mm–200mm between glass surfaces delivers optimum acoustic performance.

This gap prevents sound waves from travelling directly through the glazing units. By using different glass thicknesses between the original window and the secondary glazing panel, vibrations are disrupted, further reducing noise transmission.

This principle is particularly beneficial for older properties with thin single-glazed windows, where sound easily passes through the original pane.

Ideal for Listed Buildings and Period Homes

Secondary glazing is especially popular for listed buildings and properties in conservation areas, where replacing windows may be restricted or require listed building consent.

Because secondary glazing is installed internally and does not alter the property’s external appearance, it is widely accepted by conservation officers. It has been endorsed by heritage organisations as a practical way to improve comfort without compromising architectural integrity.

For homeowners with original windows they wish to preserve, secondary glazing offers the best of both worlds—modern performance without sacrificing character.

Thermal Benefits and Condensation Control

In addition to noise reduction, installing secondary glazing provides excellent thermal insulation. The additional glazing layer helps retain heat, reducing heat loss through existing windows and lowering heating bills.

Secondary glazing also helps eliminate condensation, a common issue with single-glazed windows. By increasing the window’s internal surface temperature, moisture formation is significantly reduced, protecting window frames and improving indoor air quality.

Over time, these energy-saving benefits contribute to improved comfort and reduced household costs.

Styles and Design Flexibility
Secondary glazing systems are suitable for almost all window types, including sash, casement, bay, and arched windows. Modern systems offer a wide range of opening options, such as:

• Horizontal and vertical sliders
• Hinged and lift-out panels
• Removable fixed glazing panels
• Top-hung and side-hung designs

Slim aluminium frames can be colour-matched to existing window frames or surrounding walls, ensuring a discreet finish that complements your home’s interior.

Curved glazing panels are also available for bespoke applications, making secondary glazing a versatile solution for even the most unique window designs.

A Cost-Effective, High-Quality Solution

Compared to full window replacement, secondary glazing costs are significantly lower while delivering exceptional performance. Because the original window remains in place, installation is faster, cleaner, and less disruptive.

When supplied and installed by a professional glazing company, high-quality secondary glazing can last for decades, offering long-term value and comfort.

Products such as Granada Secondary Glazing are designed to meet the highest standards of durability, performance, and aesthetics, providing a reliable solution for noise reduction, heat loss, and condensation.

Why Choose Thames Valley Windows

At Thames Valley Windows, we specialise in bespoke aluminium secondary glazing systems for properties in Berkshire, Hampshire, Surrey and Oxfordshire

Our experienced team ensures precise installation, airtight sealing, and maximum performance—transforming your home into a quieter, warmer, and more peaceful sanctuary while the noise stays outside.

To learn more about our secondary glazing prices, call 0800 181 698 for a free, no-obligation quote, or contact us online to arrange a showroom visit or a home consultation.