Whether you're upgrading a single sash in a lateral flat or a full set in a Georgian townhouse, configure each window individually and receive a precise price range — completely no-obligation.
6.4mm Laminated Acoustic · up to 38dB · Thermal: Good
Full-Property Estimate · 1 window · 1.08 m²
£1,134–£1,458
Inclusive of professional installation · London rates
Annual Property Saving
£120–£200/yr
Energy Saving Trust benchmark
Thermal Comfort
+3°C to +5°C
Average internal temperature rise
Noise Reduction
Up to 38 dB
6.4mm Laminated Acoustic
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Expert Analysis · 2026
When calculating secondary glazing costs, the glass choice is your most important variable. While standard thermal glass provides immediate relief from draughts, London homeowners are increasingly opting for 6.8mm Acoustic Laminate. This premium glass isn't just thicker; it features a specialised PVB interlayer that disrupts sound waves, targeting the low-frequency rumble of city traffic and aircraft.
Unlike 'off-the-shelf' kits, professional secondary glazing is custom-engineered to your window's exact millimetres. This ensures an airtight seal, which is the secret to achieving a 60% reduction in heat loss. For those in Grade II listed buildings or Chelsea conservation areas, this remains the most cost-effective way to achieve modern thermal performance without the planning headaches of full window replacement.
Our Price Promise ensures that while we use high-end materials like Stadip Silence, our efficiency as London's leading installers allows us to beat any like-for-like quote — every time.