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.
Acoustic laminate glass with an optimised air cavity silences traffic, aircraft, and urban noise.
Dramatically cuts heat loss through the largest opening in the room — bay windows lose up to 3× more heat than flat windows.
20 mm frames colour-matched to Farrow & Ball or Little Greene heritage palettes. Virtually undetectable from inside or out.
Fully reversible, internally fitted — compliant with conservation area and Grade II listing requirements across all London boroughs.
Every bay is individually surveyed and templated. Here are the three most common configurations we install across London.
The classic Victorian bay. Three flat panels joined at 135° corner posts — the most common configuration in London terraces.
Panel Layout
Typical: W 1800–2400 mm × H 1200–1800 mm
Wider Edwardian bays with five facets. Each panel is individually templated to follow the existing masonry angles exactly.
Panel Layout
Typical: W 2400–3600 mm × H 1200–1800 mm
True curved bays use toughened bent glass or segmented faceted panels (6–8 sections) to follow the radius of the bow.
Panel Layout
Typical: Radius 600–1200 mm, H 1200–1800 mm
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
Transparent pricing based on real London installations. Significantly less than full bay window replacement.
£1,200 – £1,800
Most Victorian terraces
£1,800 – £2,400
Larger Edwardian properties
£2,200 – £2,800
Bent glass or multi-facet
Prices include survey, manufacture, installation, and VAT. Final quote based on site survey.
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.
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.
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.
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.
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.
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.
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