Thermal Insulation

Reduce heat loss by up to 60-70%

Save on your energy bills

Prevent draughts

Perfect for listed buildings

Your existing single glazed windows are probably the ones that your house has had since it was built. They are draughty, the heat loss is horrendous and they make the area around them uncomfortable to be in. Changing them is expensive and disruptive and will never have as much character as your existing windows.

That’s where secondary glazing comes in.

Much cheaper than replacing, no redecorating to do and actually more effective at reducing heat loss and eliminating draughts.

Reduce heat loss by at least 60%

High performance energy efficient glasses such as Pilkington K™ will help to reduce the heat loss by up to 60-70% for perfectly sealed existing windows (and even more for existing windows that are draughty). These types of glass have reflective coatings which allow solar energy to pass through into your room but prevent it from escaping back out, eliminating condensation and drafts.

Save up to £160 a year on energy bills

By reducing heat loss, you will reduce your household energy bills. The amount of saving will obviously vary depending on the type of property, but as a point of reference, you will save around £50 a year in a small flat and £160 a year in an average detached house.

Make the most of your space

We’ve found that customers actually start to use more of the space in their home after their secondary glazing has been installed. This isn’t just because they can sit and relax nearer to their windows without feeling cold, but they realise that they didn’t want to spend time in certain rooms because they were too cold or that it cost too much to heat properly.

A necessity for historic and listed properties

For historic and listed properties, secondary glazing is often not only the best, but the sole solution to the problems that come with single glazed primary windows. But the benefits to your property aren’t just keeping the heat in.

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Hinged Casement

Fixed Windows

Lift Out Windows

Bespoke Windows

Black Knight Secondary Glazing Limited
Registered in England and Wales Number: 08638414
VAT Registration Number: 197 3861 56

Head Office

Unit 9, Prospect House, Colliery Close, Chesterfield, Derbyshire, S43 3QE

Office Tel

01246 229 000


0808 168 5208