Standard single glazing uses 4mm float glass — a pane so thin that low-frequency sound waves from buses, heavy goods vehicles, and diesel engines pass through almost unimpeded. Our 10.8mm acoustic laminate glass is engineered from two sheets of glass bonded to a specialised PVB (polyvinyl butyral) acoustic interlayer. This triple-layer construction dramatically increases the mass per square metre of the glazing, which is the single most important factor in blocking low-frequency rumble. The result is a pane that absorbs and reflects sound energy across the full audible spectrum, achieving laboratory-tested reductions of up to 54 dB — enough to turn a busy A-road into near-silence.
Our 10.8mm acoustic laminate glass is engineered from two sheets of glass bonded to a specialised PVB acoustic interlayer. This triple-layer construction dramatically increases mass per square metre — the single most important factor in blocking low-frequency rumble.
The Gap
100–150mm Decoupled Air Cavity
Sound travels as a pressure wave. When that wave hits a single barrier it causes the panel to vibrate, re-radiating noise on the other side. The physics solution is decoupling: creating two independent barriers separated by a still-air cavity. Our installations maintain a 100mm to 150mm gap between the original window and the secondary pane — a dimension validated by acoustic engineers as the "sweet spot" for residential sound insulation. Below 50mm the two panes begin to act as one coupled system, drastically reducing performance. Above 200mm there are diminishing returns and practical space constraints. Within the 100–150mm range, the trapped air column acts as a highly effective acoustic buffer, absorbing energy before it can reach the inner glass layer.
Our installations maintain a 100mm to 150mm gap between the original window and the secondary pane — validated by acoustic engineers as the "sweet spot" for residential sound insulation.
The Seal
Twin-Compression Acoustic Seals
Even the thickest glass and widest air gap are rendered ineffective if sound can leak around the frame. This is where our twin-compression acoustic seal system becomes critical. Every secondary glazing panel we install features dual-durometer EPDM rubber gaskets that compress against the frame on both the room side and the cavity side, creating an airtight perimeter with no flanking paths for noise. Unlike standard brush-pile or single-fin seals — which leave micro-gaps that allow high-frequency hiss and mid-range drone to penetrate — our twin-compression design maintains consistent contact pressure across the full frame length, even as timber frames expand and contract with seasonal temperature changes. The result is a hermetic acoustic envelope that preserves the full 54 dB performance of the glass and air-gap system.
Every secondary glazing panel features dual-durometer EPDM rubber gaskets that compress against the frame on both sides, creating an airtight perimeter with no flanking paths for noise.
Why London Homes Need Secondary Glazing Noise Reduction
Living in London's most prestigious areas shouldn't mean sacrificing peace and quiet. Traffic noise, construction, and urban activity can make homes uncomfortable and reduce property value. Traditional solutions like double glazing often aren't possible in listed buildings or conservation areas.
That's where soundproof secondary glazing excels—providing up to 54dB noise reduction with our 10.8mm acoustic glass, without altering your original windows. Our specialist secondary glazing noise reduction solutions are approved for heritage properties and deliver immediate acoustic improvements. Whether you're in a Georgian townhouse in Kensington or a Victorian terrace in Richmond, we help restore peace to your home.
London's Only Dedicated Acoustic Glazing Specialists
Unlike general glazing companies that offer soundproofing as an afterthought, we do nothing but acoustic secondary glazing—every day, in every London borough. Our 10.8mm laminated acoustic glass and precision-engineered air gaps achieve independently verified 54dB reduction, outperforming double glazing by over 20dB.
From Kensington's Cromwell Road to Richmond's Heathrow flight path, we've completed over 200 heritage installations with a 100% conservation officer approval rate. Every project includes a free professional acoustic survey, bespoke design, and our comprehensive 25-year warranty.
54dB verified noise reduction
Grade I, II* & II listed approved
25+ years London-only specialists
100% conservation consent rate
25-year warranty on every install
The Science Behind Secondary Glazing Noise Reduction
Not all glazing is equal. Compare decibel reduction across solution types to see why 10.8mm acoustic glass is the professional's choice.
Solution Type
Typical dB Reduction
Frequency Analysis
Best For
Standard Double Glazing
28–32 dB
Mid only
Thermal insulation only
6.4mm Laminate Glass
35–38 dB
Mid–High
Light traffic & general ambient noise
10.8mm Acoustic Specialist Glass
Premium Choice
45–54 dB
Low–Mid–High
Heavy sirens, trains & city noise
dB figures based on independent laboratory testing. Actual performance varies by installation, air-gap depth, and window condition.
Our Secondary Glazing Services
We offer comprehensive secondary glazing solutions tailored to your specific needs. Each service is delivered by our experienced team with minimal disruption to your property.
Authoritative sources supporting the information in this article.
British Standards Institution (BSI) (2017). Building acoustics. Estimation of acoustic performance of buildings from the performance of elements. Airborne sound insulation against outdoor sound. BS EN ISO 12354-3:2017.Open source
This standard provides the fundamental framework for estimating the acoustic insulation of buildings and components in the UK, essential for calculating noise reduction in London residences.
HM Government (Department for Levelling Up, Housing and Communities) (2015). Approved Document E: Resistance to the passage of sound. Building Regulations 2010 (UK).Open source
This statutory guidance outlines the requirements for protection against noise and sound transmission in dwellings, supporting the necessity of secondary glazing in high-noise urban environments.
Historic England (2017). Modifying Historic Windows as Part of Retrofitting Energy-Saving Measures (PPG24 Equivalent). Historic England Advice Note.Open source
A critical resource for London property owners, explaining how secondary glazing acts as the preferred acoustic and thermal solution for listed buildings where replacement windows are prohibited.
The Glass and Glazing Federation (GGF) (2021). Window Film and Glazing: Acoustic Performance and Sound Insulation Properties. GGF Technical Publication 4.2.Open source
Provides industry-standard technical data on how cavity widths between primary and secondary glazing can achieve noise reductions of up to 54dB or higher.
British Standards Institution (BSI) (2017). Thermal performance of windows, doors and shutters. Calculation of thermal transmittance. General. BS EN ISO 10077-1:2017.Open source
Establishes the benchmarks for thermal efficiency (U-values) that secondary glazing helps London property owners achieve in addition to acoustic gains.