Secondary Glazing: The Ultimate Solution for Acoustic & Thermal Insulation in Heritage Homes

Secondary Glazing: The Ultimate Solution for Acoustic & Thermal Insulation in Heritage Homes

Secondary glazing is often mistakenly viewed as a mere compromise—a solution only for heritage properties in Conservation Areas where building controls prevent the installation of new double glazing.

The reality, however, is that a professionally installed secondary glazing system is not just an aesthetic safeguard; it is a high-performance upgrade that offers superior soundproofing and enhanced thermal efficiency, often outperforming standard modern double glazing. This makes it an ideal investment for any homeowner in Hampshire or Dorset looking to make their home quieter, warmer, and more secure without altering the exterior character.

🎧 Unmatched Soundproofing: Cutting Noise by up to 70%

If you live near a busy road, flight path, or industrial area, you understand the detrimental impact noise pollution can have on health and comfort. While standard acoustic double or triple glazing can reduce noise, secondary glazing goes one better, with the right specification able to cut noise pollution by up to 70%.

The Acoustic Air Gap Principle

The key to this dramatic noise reduction lies in the creation of a substantial, sealed air space between the original window and the new internal pane. Sound waves are physical vibrations. When they hit the first pane of glass, they are ‘refracted’ or broken up. As they travel across the air gap and hit the second pane, this process repeats, disrupting and absorbing energy from the sound waves.

To achieve optimum sound insulation:

• Optimal Gap Size: For maximum performance, aim for a space of 150mm between the primary (existing) and secondary panes if the original glass is thin (e.g., 3mm or 4mm). If the original glass is thicker (e.g., 6mm), a 100mm gap may suffice.
• Acoustic Glass Enhancement: If an ideal gap cannot be achieved due to the window sill size, specifying acoustic glass provides extra performance. This laminated glass uses multiple layers of different thicknesses and a dampening layer to create more hurdles for the sound wave to pass through, significantly boosting performance.

🌡️ Maximizing Thermal Efficiency and Energy Savings

The air gap created by secondary glazing is essentially a highly effective second layer of insulation, significantly boosting the thermal efficiency of the whole window unit.

Energy-Saving Specifications

• Low-E Glass: While all secondary glazing will improve thermal performance, you should specify an ultra-energy efficient low emissivity (Low-E) glass to maximize savings. Products like Pilkington K Low-E glass cut the transfer of heat between the inside and outside, ensuring that valuable heat stays inside during winter.
• Creating a Barrier: The secondary pane and the original window form a sealed thermal pocket. This barrier drastically reduces heat loss and eliminates drafts, making the room feel noticeably warmer and reducing your energy bills.

🏰 Ideal for Heritage Properties and Conservation Areas

For homeowners whose properties are listed or located within conservation areas, secondary glazing is often the only permissible way to upgrade performance without risking lengthy planning battles.

• Preservation: Secondary glazing preserves the external character, sightlines, and historical features of the original windows (including beautiful sash windows).
• Compliance: It allows you to comply with the necessary thermal requirements for modern living while respecting planning controls that prohibit replacing the original external fabric.

🛠️ Choosing the Right Secondary Glazing System

Modern secondary glazing systems are discreet, easy to use, and secure.

• Materials: We supply and install aluminium secondary glazing systems due to their exceptionally slim sightlines, which minimize their visual impact, and their high security. These systems can be fixed directly to your existing window frame or manufactured with a sub-frame (MDF or hardwood) for face-fixing.
• Styles: Available styles include horizontal and vertical sliding designs, as well as hinged or ‘lift out’ units, ensuring there is a style to match every original window design.

For maximum results, expert installation is paramount. KJM Group ensures the correct spacing, sealing, and alignment of your unit for decades of smooth, high-performance operation.

Ready to gain superior soundproofing and thermal comfort without compromising your home’s character?

Get a quote

Call Our Andover Experts: 01264 359355

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Mark Pearce

With over four decades in the glazing industry, Mark Pearce has been at the heart of KJM Windows & Conservatories since 1983. Starting as a building labourer, he quickly rose through the ranks, working as a window and door installer from 1984, a factory operator manufacturing windows later that year, factory manager in 1992, and joining the sales team in 1994. Becoming a Director in 2002, and finally, the sole owner in 2010, Mark Pearce is truly a double glazing expert and has led KJM to become a leading supplier of high-quality windows, doors, and conservatories across Andover and the South of England.

Mark Pearce is a highly experienced specialist in the double glazing industry, having built his knowledge from the ground up through hands-on experience in installation, manufacturing, sales, and business management. Beyond his role at KJM, Mark is a keen blogger, writer, and traveller, often sharing insights on the latest innovations in the home improvement industry.

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