Secondary glazing you can rely on


Design  |  Manufacture  |  Install

Book a FREE consultation

Thermal Insulation

Reduce heat loss, draughts and save on your energy bills

Noise Reduction

Block out external noise and get a good nights sleep

Increased Security

Add an extra layer of security to your home

Reduce Condensation

Enjoy a cleaner, drier and a more comfortable home

What is secondary glazing?

Secondary glazing is an additional, discreet internal window that works alongside an existing single, double or triple glazed window. It’s cost-effective, efficient and provides a number of performance based benefits to homes and commercial buildings. It’s most common use is for Listed Buildings and conservation areas.


Why should you fit secondary glazing?

Whether the problem you currently face is heat loss, draughts or too much noise from your existing windows, it is the best possible solution to make your home more comfortable and reduce your heating costs.

Our expert installers will ensure that their many years of experience are used to fit the units effectively, correctly, quickly and with minimal disruption.

Horizontal Sliders

Vertical Sliders

Hinged Casement

Fixed Windows

Lift Out Windows

Bespoke Windows

Installing secondary glazing can reduce heat loss by up to 60-70%

Find Out More

What Our Customers Say

A pleasure to deal with a very friendly and knowledgeable man. Very refreshing to meet somebody who really understands the product he is selling and able to offer genuine advice.

IH, County Durham

 Many thanks for completing the secondary glazing to my front bedroom. The difference in sound reduction is better then I expected and the room is now a lot warmer too.

SC, Leeds

All your colleagues have been very helpful. The project has all been arranged and executed so promptly. What a contrast to other secondary glazing suppliers I have come across!

ME, London

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