Double Glazing Explained

Double Glazing Explained

What is retrofit double glazing?

Retrofit double glazing is the process of retrospectively fitting new energy efficient double glazing into existing window frames that previously held single glass. The process involves removal of the inefficient single glass and small changes to the existing frames which may include changing the timber or aluminium beads to accommodate double glazing. However, unlike alternative options available, these small changes will be almost un-noticeable, resulting in a finished product that maintains the authenticity of your existing windows.

This means that:

  • Timber window frames are kept consistent without having any additions that compromise the aesthetics and insulation performance.
  • Aluminium window frames are kept consistent including functionality of opening windows and doors.

The Double Glazing Company has developed the retroGLAZE® system to provide existing homes with the benefits of double glazing without requiring the entire replacement of their joinery.

Joinery Maintenance

Windows have components that wear over time. This includes items like window handles/ catches, stays/ hinges, gasket and draught seal’s. As part of ‘retroglazing’, the required maintenance and optional upgrading of hardware is carried out. The outcome is that the windows and doors are refurbished and double glazed all at once.


A number of alternatives are often confused with retrofit double glazing:

Insert double glazing

Where new aluminium framed double glazed windows are inserted into existing timber frames. This can be a useful alternative where the timber joinery has been under maintained and subject to rotting – and where the authenticity of the timber character is not important to the home owner.

Clip-on, or magnetic seal secondary glazing

Where a piece of glass or perspex is fitted to the existing single glazed window. The lack of an effective seal means that moisture, dust and mould can occur between the two panes. Often portrayed as a cheaper alternative, it can prove to be significantly more costly.

In considering retrofit double glazing, it is important to understand what you are getting for your money. In buying products together with an installation service, for an existing home, there is more ‘to get right’. The Double Glazing Company has developed retroGLAZE® for this reason.  We think that homeowners should be able to have quality products installed correctly with excellent service.

Whatever your double glazing needs are, you can be confident that we will provide the right retroGLAZE solution for your home

Double glazing questions

Explore our retroGLAZE® solutions

Timber Retrofit

Retain the character & superior insulating properties of timber, upgraded with high performing double glazing.

Aluminium Retrofit

Upgrade your existing single glazed aluminium windows & doors to high performing double glazing.

Replacement windows with new double glazing

Replacement Windows

Refresh and modernise your home with new high performance windows and doors