Thermal Performance

Substantially improves the thermal insulation of existing single-glazed windows

Acoustic Insulation

Secondary glazing can drastically reduce noise levels for property’s that have single, double or triple glazing.

Increased Security

Secondary glazing is extremely difficult to open from the outside and provides an additional physical barrier against forced entry.

Condensation Control

Secondary glazing with balanced trickle ventilation. This provides a simple, cost-effective, and permanent solution.


Secondary Glazing is the process of installing a Secondary Window over the Primary Window to create the benefits of a double glazed window system. The benefits of Secondary Glazing over Double Glazing is that the Secondary Glazing option allows you to retain the character, both inside and out of the original window, whilst still increasing thermal and acoustic performance offered by double glazing. This makes Secondary Glazing an ideal choice for Listed Buildings. In some instances, Secondary Glazing can actually outperform a double glazing system with a u-value as low as 1.3w/m2k achieved with secondary glazing and heavy curtains.



Does the primary window require access for opening or maintenance? If the answer to this question is no, then a simple lift out or fixed panel insert can often be the best and most cost effective solution. The lack of moving parts makes them cheaper to manufacture.


The sightlines of the window should also be considered. Usually, the Secondary Glazing unit is installed to mirror the primary window. However, there are occasions when a different style can be more effective. A great example is on a pair of Vertical Sliding box sash windows, where you could choose to have two Vertical sliding secondary glazing units for each or use one single horizontal slider across both windows.

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Product Options

RAL Colours

All aluminium frames are painted white as standard, though you can select from over 200 RAL colour options – to mirror the look and feel of your home.

Standard colours come with a 15% uplift, Non Standard Colours are POA + RAL set up charge