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Secondary Glazing

contemporary styling, high quality, award-winning manufacturer

Specialist Secondary Glazing

Secondary double glazing is ideal for flats, houses and commercial premises where there is a need to reduce outside noise and improve thermal insulation, especially where the character of the property makes more modern replacement windows inappropriate or, in the case of Listed or Conservation Area properties, where they are not allowed.

If you are looking to improve the energy efficiency of your windows but would prefer not to replace them, your original windows can be double glazed, draught proofed and sealed without any damage to the existing windows in your home.

In addition to improving the acoustic and heat insulation of your home, secondary double glazing also increases security.

Sash window style

Here we show how the introduction of secondary glazing can be completely in keeping with the original windows and this is perfect when insulating windows that are within a preservation area.

White Aluminium and energy saving glass with slimline effect with no visible external effect.

Sliding windows

Sliding sash style windows insulated with white Aluminium secondary glazed units.

White Powder coated secondary glazed units with acoustic glass for sound insulation, also the easy clean option enables you to tilt the window in for very easy cleaning.

Horizontal sliding windows

Horizontal sliding secondary glazed window which enable the full use of original window with excellent thermal and sound insulation.

White or coloured powder coated aluminium secondary units can be fitted directly to the inside of your window or produced using hardwood sub-frame which enables the secondary window to be fixed to suit any application.

Secondary hinged units

Hinged secondary glazed windows offer great sound and heat insulation with the benefit of large open views if required.

Hinged secondary glazed windows enable large windows to be covered and give great views without obstruction also they are very easy to clean.


The window rating system looks at three aspects of performance:

  • The U value (heat loss)
  • The G value (solar gain)
  • The L value (air leakage)

Although these ratings apply to a complete window i.e. the frames and the glass combined. Glass itself plays a major part in the rating that a double glazed window achieves.

Within our range we offer a fantastic choice of energy rated windows. All our options carry the energy saving recommended logo. This coveted logo is awarded to the most energy efficient windows that can help to cut your energy output and help prevent climate change.

By installing windows from the Crystal Clear range you will be helping improve the overall performance of your home. Which will not only reduce your heating bills and CO2 emissions but it could improve the value of your property and speed up any future sale.

Other benefits

Other benefits of installing Crystal Clear energy windows include.

Reduction in condensation of up to 70% virtually eliminating the potential breeding ground for a range of bacteria, mould and dust mites that could be harmful to people who have respiratory conditions.

Reduction in noise transmission by up to 2 DB which helps you keep your home an oasis of calm, away from the noise of the outside world.

94% reduction in heat loss which helps to warm your home, not the environment.

For more on energy efficiency ratings contact Crystal Clear today, our experts can help answer any of your questions.