Enhance your heritage property with unobtrusive secondary glazing solutions
Here to help
Glevum’s secondary glazing fits discreetly within existing window frames to enhance thermal insulation, reduce noise, and improve security, while maintaining your property’s historic character.
Many homeowners are unaware of effective alternatives to replacing inefficient single-glazed windows. Secondary glazing provides a simple solution by adding a discreet second pane inside the existing window, creating an insulating air gap that enhances warmth and reduces noise. Avoid the cost and disruption of full window replacement with secondary glazing from Glevum.
Ideal for listed buildings where the external aesthetic needs to be preserved.
Our secondary glazing is available as horizontal, vertical, hinged, lift-out, or fixed units. We offer tailored solutions for all properties, including listed and heritage buildings.
Reduce noise by up to 80%, decrease heat loss by 65%, and improve security with discreet panels that integrate seamlessly with your home’s design. Book a free home visit to see how secondary glazing can enhance your comfort and security.
What is Secondary Glazing?
Benefits of Secondary Glazing:
Noise Reduction: Secondary glazing offers the highest level of noise reduction, outperforming other glass solutions. Glevum’s secondary glazing is manufactured with advanced machinery to ensure a tightly sealed frame, reducing noise by up to 80% (50dB).
Energy Efficiency: Secondary glazing adds an extra barrier to reduce heat loss. The gap between the existing window and the secondary unit acts as an insulator, reducing heat loss by up to 65%.
Enhanced Security: Secondary glazing serves as an effective deterrent to intruders. It is difficult to open from the outside, providing an additional barrier against forced entry. The frames are made from durable, high-quality aluminium and are securely fixed.
Condensation Control: Secondary glazing helps control condensation by providing a complete internal seal that balances ventilation within the window cavities. This prevents the inner glass from becoming too cold and reduces condensation.
Seamless Aesthetics: Glevum’s secondary glazing features a sleek, modern design that delivers acoustic, thermal, and security benefits without compromising style.
What is secondary glazing, and how does it benefit heritage properties?
Secondary glazing is a slim, discreet aluminium panel installed inside your existing window, nearly invisible when correctly fitted. It enhances thermal insulation, noise reduction, and security without altering the building's original style, making it ideal for heritage properties.
How effective is secondary glazing at reducing noise and heat loss?
Secondary glazing can reduce noise levels by up to 80% and decrease heat loss by approximately 65%, significantly improving comfort and energy efficiency in your home.
Can secondary glazing be installed on any type of window or property?
Yes, secondary glazing is versatile and can be tailored to all property types, including listed and heritage buildings, with options like horizontal sliding, vertical sliding, hinged, lift-out, and fixed units.
Will secondary glazing affect the appearance of my property's character?
No, Glevum's secondary glazing is designed to blend seamlessly, maintaining your property's aesthetic appeal while providing superior thermal, acoustic, and security benefits.
How do I choose the right secondary glazing solution for my property?
Consulting with specialists like Glevum ensures you receive a tailored solution suited to your property's style, whether it's modern, traditional, listed, or heritage, for optimal performance and appearance.
Horizontal Sliding
Arguably, it is the most popular Secondary Glazing option. Horizontal sliding secondary glazing units are slim, versatile, and easily accessed for cleaning and ventilation. The perfect fit for all property types and styles,
Vertical Sliding
This secondary glazing option is perfect for heritage properties and modern buildings alike. Vertical sliders have a tilt option that enables both panels to pivot inwards for easy access and cleaning individually.
Hinged Casement
Hinged windows can be installed with any style of original window from casement to traditional box sash. Our secondary glazed panels open into the room with hinges positioned on whichever side you wish.
Lift Out
The lift-out solution is the most ‘removable’ product in the entire range. It is ideal for listed and heritage properties where installing double glazing is not a viable option. It is also ideal for windows that require only occasional access, with the unit capable of being easily lifted out when required.
Fixed Unit
Fixed secondary glazing features an independent unit that is neatly fitted on the interior side of the primary window. As an effective alternative to a complete window replacement, the fixed units provide significant noise reduction, thermal performance, and enhanced security.
Bespoke and Arched
For every unique window, there is a secondary glazing solution. Our decades of experience mean we fit every window precisely to your spec. There is virtually no limit to the type of property that can be improved with our broad range of available solutions.
Related Blog(s)
We are a proud supplier of Granada Secondary Glazing (The UK's largest bespoke secondary glazing manufacturer).
“Friendly, helpful staff from sales person to fitter, excellent service all round.”
J Holyhead (Gloucestershire)
March 2026
“Very helpful and reassuring. My window and door were fitted by 2 very nice men and its prefect, we are so pleased, thank you so much.”
K Smith (Gloucestershire)
February 2026
“Very professional service from the quote to the fitting. Very pleased.”
J Ochiltree (Gloucestershire)
January 2026
“We have used Glevum many times over the last 25 years and have never been disappointed with the quality of workmanship, timely service and friendly approachable people.”
M Tattersall (Gloucestershire)
January 2026
"Excellent service and workmanship. Highly recommend."
M Tomlin (Gloucestershire)
November 2025
"Glevum were very professional throughout the purchase and installation and I am happy with the finished result. Installation team were courteous, neat and tidy throughout the process."
R Elliott (Gloucestershire)
November 2025
“Friendly, helpful staff from sales person to fitter, excellent service all round.”
J Holyhead (Gloucestershire)
March 2026
“Very helpful and reassuring. My window and door were fitted by 2 very nice men and its prefect, we are so pleased, thank you so much.”
K Smith (Gloucestershire)
February 2026
“Very professional service from the quote to the fitting. Very pleased.”
J Ochiltree (Gloucestershire)
January 2026
“We have used Glevum many times over the last 25 years and have never been disappointed with the quality of workmanship, timely service and friendly approachable people.”
M Tattersall (Gloucestershire)
January 2026
"Excellent service and workmanship. Highly recommend."
M Tomlin (Gloucestershire)
November 2025
"Glevum were very professional throughout the purchase and installation and I am happy with the finished result. Installation team were courteous, neat and tidy throughout the process."
R Elliott (Gloucestershire)
November 2025