Secondary Glazing | Altegra

Aluminium Secondary Glazing

Improve both the thermal and acoustic performance of existing windows

Add extra performance with aluminium secondary glazing

Our range of aluminium secondary windows are designed for double-glazing existing primary windows. Easily fitted and operated, the system allows for cleaning and maintaining both the existing primary and applied secondary window. When installed, the system provides all the thermal and acoustic advantages of double-glazing.

Secondary glazing is a fully independent window system installed to the room side of existing windows. The original windows remain in position and in their unaltered form.

Suitable for both commercial and residential
projects, secondary glazing is available as open-able, removable or fixed units. The open-able panels can be either side hung casements or horizontal or vertical sliding sashes. These allow access to the external window for cleaning and the opening of both the secondary glazing and external windows for ventilation. Fixed forms of secondary glazing are designed to be removed in warmer months when the thermal benefits are not required.

SSG Secondary Glazing PNG

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Performance and looks

Secondary glazing is suitable for a wide range of both commercial and residential applications; listed buildings, conservation areas, offices, schools, colleges, universities, hospitals and hotels.
  • Available in 4mm and heavy duty 6mm glazing for extra performance.
  • Wide variety of colours to blend with internal décor.
  • Stocked in white for superfast delivery.
  • Concealed perimeter fixings to enhance appearance.
  • Designed for double-glazing existing primary windows
  • Easily fitted and operated
  • Improved thermal insulation for Building Regulations and BREEAM®
  • Increased acoustic insulation (Controls noise: Building Regulations Approved Document E)
  • Enhanced Security 
  • Suitable for listed buildings conserving the exterior character of a period property


  • Single Light Duty/Fixed Light
  • Single Fixed Light
  • Hinged Lights
  • Lift-Out
  • Horizontal Sliding
  • Vertical Sliding
Secondary Glazing

Benefits of Aluminium Secondary Glazing

Aluminium secondary glazing is the installation of a second layer of glazing, typically made of aluminium, on the interior side of existing windows in a building. This secondary layer acts as an additional barrier against noise, heat, and cold, and offers several benefits, including:

  1. Improved Thermal Insulation: Aluminium secondary glazing can significantly enhance the thermal insulation of a building by reducing heat loss through windows. The secondary layer acts as an extra barrier, helping to keep the cold air out in winter and preventing warm air from escaping, resulting in increased energy efficiency and reduced heating costs.

  2. Enhanced Sound Insulation: Secondary glazing can provide an additional layer of sound insulation, reducing external noise, such as traffic or aircraft noise, from entering a building. This can help create a quieter and more comfortable indoor environment, particularly for buildings located in busy or noisy areas.

  3. Increased Security: Aluminium secondary glazing can improve the security of a building by adding an additional layer of protection to windows. The tough aluminium frames and glass provide an extra barrier that is difficult to breach, making it more challenging for intruders to gain entry through windows.

  4. Retained Original Windows: One of the significant advantages of aluminium secondary glazing is that it can be installed on the interior side of existing windows, without altering their appearance or functionality. This allows for the retention of the original windows, which may have historic or aesthetic value, while still enjoying the benefits of improved insulation, noise reduction, and security.

  5. Reduced Condensation: Condensation can be a common problem with single-glazed windows, particularly in colder climates. Aluminium secondary glazing can help reduce condensation by creating an additional insulating layer, which can help keep the interior glass surface warmer, reducing the likelihood of condensation forming on windows.

  6. Cost-effective Solution: Aluminium secondary glazing can be a cost-effective alternative to replacing existing windows with double-glazed windows, especially in situations where the replacement of windows is not feasible or desirable, such as in heritage buildings or rented properties. Secondary glazing can provide similar benefits to double glazing at a lower cost, making it a more budget-friendly option.

  7. Easy Installation and Maintenance: Aluminium secondary glazing is relatively easy to install and maintain. It can be retrofitted onto existing windows without major structural changes, and maintenance typically involves simple cleaning and occasional lubrication of moving parts, making it a convenient and hassle-free solution.


We can tailor all of our aluminium doors to match any requirement and project

Altegra manufacture the highest quality aluminium door systems supplying both the trade and commercial sectors. Our experienced sales team and technical department are here to assist in any aspect of your project, quoting from specifications or off plan.

All aluminium doors are fitted with energy-efficient double glazing (single and triple glazing options available) and toughened safety glass as standard.

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Manufactured in the UK

We have a dedicated manufacturing team who make all of our aluminium systems. All projects we take on all conform to the highest standards backed by industry known accreditations. 

Made to order

At Altegra, all of our bespoke aluminium windows and doors are made to order. This ensures that it meets your exact requirements.

Fast turnaround times

All aluminium windows, doors, shopfront systems and curtain wall systems are manufactured and made to order with industry leading turnaround times; ensuring your project is not delayed.


What makes Altegra stand out?

UK Made-1

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