Secondary glazing is the installation of a second pane of glazing inside an already existing pane. It’s the simplest, most reversible and most cost-effective alternative to ripping out and replacing your windows — and it delivers many of the same comfort gains.
At Wind-Do Seal, every secondary glazing system is custom built and fitted to suit your specific windows and needs — including period sash and casement windows where retaining the original frame really matters.
Learn About Our Secondary Glazing
Our made-to-measure secondary glazing systems are fitted inside your existing windows, helping to reduce draughts, improve insulation, increase security and dramatically reduce outside noise without replacing your original windows.
View Secondary Glazing →A practical secondary glazing option for wider windows, offering easy access and smooth sliding operation.
Ideal for sash-style windows where the secondary glazing needs to work with the existing window design.
In-frame hinged panels provide simple access for cleaning, decorating and day-to-day window use.
A discreet removable option for windows that only need occasional access while improving comfort indoors.
The details behind the system.
We start with a free on-site survey to measure every window and discuss what you're trying to achieve — quiet, warmth, security, or all three. Each unit is then manufactured to fit your exact opening and installed in a single visit per window, with no disruption to the original frame. Hinged, lift-out or slider opening options are available so you can still ventilate, clean and access your existing windows.
Our standard system delivers a noticeable drop in noise levels — typically dramatic enough that traffic, nightlife and street noise stop interrupting sleep and conversation. The trapped air gap between the original window and the secondary pane also pushes up U-values, cutting heat loss through what's usually the coldest part of a room.
Because the original window stays exactly as it is, secondary glazing is ideal for protected structures, Georgian and Victorian properties, and any building where the external appearance can't change. We've fitted it in homes, schools, hotels and government buildings across the country.
Keep the original sash and gain modern thermal and acoustic performance.
Stop guest complaints about street noise without closing rooms for renovation.
Quieter meeting rooms and warmer winters in older office buildings.
Calmer environments where noise reduction directly improves outcomes.
City-centre flats transformed for tenants suffering from traffic and pedestrian noise.
Even modern double glazing can be boosted further when very high noise reduction is needed.
