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Soundproof Window Specialists London | Acoustic Secondary Glazing

Reclaim Your Peace.

London's leading soundproof secondary glazing specialists. Our 10.8mm acoustic laminate glass delivers up to 54dB noise reduction — the highest available for residential properties. Heritage and listed building window specialists serving Belgravia, Chelsea, Richmond, Hampstead, Notting Hill, Mayfair, and all London boroughs. Free noise survey. Prices from £350 per window. No planning permission required.

We are London's trusted listed building secondary glazing installers. Whether you face traffic noise from the A316, Heathrow flight path disturbance, or nightlife noise in Portobello Road, our bespoke acoustic solutions — fully compliant with conservation area requirements — transform your home into a sanctuary of silence. Westminster enforcement alone won't fix your noise problem. Properly specified secondary glazing will.

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    Bay Window Specialists

    Bespoke Secondary Glazing for Bay Windows

    Custom-templated 3-panel, 5-panel, and curved bay window secondary glazing with 10.8 mm Stadip Silence acoustic glass. Up to 54 dB noise reduction — heritage approved across every London borough.

    Acoustic secondary glazing fitted to a Victorian bay window in London

    Noise Reduction

    54 dB

    The Bay Window Challenge

    Why Bay Windows Need Specialist Secondary Glazing

    Bay windows are the most acoustically vulnerable opening in a period property. Their angled geometry, larger glass area, and multiple joints create more paths for sound transmission.

    Up to 54 dB Noise Reduction

    Acoustic laminate glass with an optimised air cavity silences traffic, aircraft, and urban noise.

    40% Better Thermal Efficiency

    Dramatically cuts heat loss through the largest opening in the room — bay windows lose up to 3× more heat than flat windows.

    Invisible Heritage Installation

    20 mm frames colour-matched to Farrow & Ball or Little Greene heritage palettes. Virtually undetectable from inside or out.

    Listed-Building Approved

    Fully reversible, internally fitted — compliant with conservation area and Grade II listing requirements across all London boroughs.

    Bespoke Configurations

    Bay Window Panel Configurations

    Every bay is individually surveyed and templated. Here are the three most common configurations we install across London.

    135° joints

    3-Panel Canted Bay

    The classic Victorian bay. Three flat panels joined at 135° corner posts — the most common configuration in London terraces.

    Panel Layout

    • Left Angled Panel
    • Centre Fixed/Sliding Panel
    • Right Angled Panel

    Typical: W 1800–2400 mm × H 1200–1800 mm

    150° joints

    5-Panel Canted Bay

    Wider Edwardian bays with five facets. Each panel is individually templated to follow the existing masonry angles exactly.

    Panel Layout

    • Far Left
    • Left Angled
    • Centre
    • Right Angled
    • Far Right

    Typical: W 2400–3600 mm × H 1200–1800 mm

    Continuous joints

    Curved / Bow Bay

    True curved bays use toughened bent glass or segmented faceted panels (6–8 sections) to follow the radius of the bow.

    Panel Layout

    • Segmented faceted panels following the arc

    Typical: Radius 600–1200 mm, H 1200–1800 mm

    Technical Specification

    Engineered for Bay Geometry

    Our bay window systems are purpose-built — not adapted from flat-window products.

    Glass

    10.8 mm Stadip Silence acoustic laminate

    Frame

    20 mm slimline aluminium, colour-matched

    Air Gap

    100–150 mm (optimised per bay depth)

    Noise Reduction

    Up to 54 dB (STC 50+)

    U-Value Improvement

    From ~5.0 → ~1.8 W/m²K

    Corner Posts

    Bespoke angled mullions, 12 mm profile

    Sash bay window with bespoke secondary glazing panels installed
    Investment Guide

    Bay Window Secondary Glazing Costs

    Transparent pricing based on real London installations. Significantly less than full bay window replacement.

    3-Panel Canted Bay

    £1,200 – £1,800

    Most Victorian terraces

    5-Panel Canted Bay

    £1,800 – £2,400

    Larger Edwardian properties

    Curved / Bow Bay

    £2,200 – £2,800

    Bent glass or multi-facet

    Prices include survey, manufacture, installation, and VAT. Final quote based on site survey.

    Common Questions

    Bay Window Secondary Glazing FAQ

    Can secondary glazing follow the angles of a Victorian bay window?

    Yes. Every panel is individually surveyed and templated to match the exact angles of your bay — whether 135° canted, 150° canted, or a continuous bow curve. Bespoke corner posts join panels at the precise angle of the masonry.

    How much noise does bay window secondary glazing reduce?

    With 10.8 mm Stadip Silence glass and a 100–150 mm air gap, bay window secondary glazing achieves up to 54 dB reduction (STC 50+). This is equivalent to reducing a busy A-road to the level of a quiet library.

    Will secondary glazing affect the appearance of my bay windows?

    No. We use 20 mm slimline aluminium frames that are colour-matched to your existing woodwork. The secondary panels sit inside the reveal and are virtually invisible from both inside and outside the property.

    Do I need planning permission for bay window secondary glazing?

    In most cases, no — secondary glazing is an internal modification. However, if your property is Grade I listed, you should consult your local conservation officer. Grade II listed buildings and conservation areas in London generally permit secondary glazing. Read our full planning guide for details.

    How long does a bay window installation take?

    A standard 3-panel canted bay takes approximately half a day. Larger 5-panel or curved bays may require a full day. There is no external scaffolding or disruption to neighbours.

    What is the cost of secondary glazing for a bay window?

    Bay window secondary glazing typically costs £1,200–£2,800 per bay depending on size, configuration, and glass specification. This is significantly less than replacement double-glazed bay units (£4,000–£8,000) while delivering superior acoustic performance.

    Ready to Soundproof Your Bay Windows?

    Book a free, no-obligation bay window noise survey. We'll measure your bay angles, assess the acoustic environment, and provide a fixed-price quote on the spot.