Secondary Glazing

What is secondary glazing?

Secondary glazing is a simple, cost-effective and efficient way to create a quieter, warmer and more secure home for you and for your family.

Why should I install secondary glazing?

Aluminium secondary glazing involves installing a discreet internal window in addition to your existing single, double or triple glazed window. This high performance yet affordable solution provides greater thermal insulation, reduces noise intrusion and improves security.

Expertly fitted secondary glazing provides a virtually invisible unique barrier that can dramatically improve energy efficiency and security, reduce draughts and noise from external sources. Slimline aluminium frames that can be powder coated in a choice of over 200 RAL colours ensure that it blends in and doesn’t change the appearance of your home.

Secondary glazing units are lightweight, simple to install without disruption to your home and require minimum maintenance.

Our range of secondary glazing is carefully manufactured by Granada Glazing who are the UK’s leading manufacturer of aluminium secondary glazing. They offer a wide range of products suitable for all homes, including listed properties and Conservation Areas.

What are the benefits of secondary glazing?

The main benefits of installing secondary glazing are:


Secondary glazing is a most effective way of cutting out external noise and reduce traffic noise from a roar to a whisper. When correctly fitted, sealed and set the optimum distance from the internal face of the primary window, it can reduce noise levels by up to 80% or the equivalent of 54dB – this noise difference will turn the sound of a diesel bus to a whisper.

For the best acoustic performance, it is advised that secondary glazing is installed with a gap from 150mm to 200mm from the main window. If this gap can’t be achieved or for noise sources that are challenging to reduce, we recommend the installation of an acoustic laminated glass within our product. Blinds and ornaments can still be displayed on the windowsill as secondary glazing is slimline and discreet.


Warmth is a valuable commodity in our homes. Research shows that up to 10% of heat is lost through your windows. Cold draughts and condensation are eliminated with secondary glazing as the extra barrier creates an insulating layer to prevent warmth escaping.

Secondary glazing provides excellent thermal insulation, reducing heat loss by up to 65%. Low-E glass is often the best choice as this has a special coating to reflect heat back into the room.

As well as creating a more comfortable environment inside the home, secondary glazing also saves money on energy bills.


Windows are often regarded as the weak point in building security. Secondary glazing offers an affordable, unobtrusive and highly effective solution for extra protection.

For homes, the benefits are clear. Unlike single glazed windows, secondary glazing is extremely difficult to open from the outside and provides an additional physical barrier against forced entry.

Granada’s secondary glazing can be locked from the room side to enhance security and safety. The frames are made from strong aluminium, securely fixed to resist forcing and can be installed with security glass.

Wide range of secondary glazing products

Whatever the size or style of your property, Granada Glazing offers the bespoke secondary glazing solution to suit your home interior and your lifestyle.

For Listed Buildings and those in Conservation Areas, secondary glazing is often the preferred option where the original windows cannot be replaced due to planning restrictions.

For older or historic properties with single glazed windows, installing secondary glazing will eliminate cold draughts and keep the building warmer, quieter and more secure. The slimline discreet frames are undetectable from the outside, maintaining the charm, character and value of your home.

Secondary glazing is the ideal and affordable solution that brings 21st century levels of comfort to older and historic properties. In most cases, installation is easily reversible if required.

Types of secondary glazing

Granada Glazing offers a wide range of secondary glazing products that are manufactured to your bespoke requirements to suit your home and your lifestyle.

The range covers horizontal and vertical sliding windows, hinged casement and lift out windows that allows easy access for maintenance and ventilation purposes. Where a window is rarely used, fixed secondary glazing can be fitted.

Granada Glazing can also supply arched and curved windows to suit even the most demanding project requirements.

Secondary glazing in any colour

Secondary glazing is available in six popular colours including; white, cream, black, grey and brown, and are always in stock. Granada Glazing can also manufacture frames in more than 200 RAL colours to match your internal décor.

With high performing and aesthetically pleasing secondary glazing, you can look forward to a more peaceful, comfortable and secure home.

Secondary Glazing Testimonial

“The fitters were on time and our door was installed with the minimum of fuss. They were very courteous and after the door was installed, made good the render on the outside, including Tyrolean finish which we were not expecting.

We were very happy with the quality of the door and the installation.”

Quality of work: 10
Timeliness: 10
Courtesy: 10

Mr Burry

We have both been so pleased with the windows, they look great and very easy to maintain and clean. Friends can’t believe that they are not made from wood. We highly recommend them.

Mr & Mrs Hodges