Secondary Glazing for Sash Windows

Our internal Glass Shutters retain warmth while preserving the appearance and functionality of your traditional sash windows.



  • Reduce heat loss by up to 40%*
  • No need for Double Glazing
  • Manufactured from Heat Retaining Glass
  • Lowers Energy Bills
  • Preserves Original Sliding-Sash Windows
  • UV Ray Protection Available
  • Virtually Invisible from External View
  • Professional Installation
*Recent research by the University of Ulster has stated that our glass shutters reduce heat losss by over 40%

Glass Shutters are made from 6mm toughened heat retaining glass. The coating on this glass reflects heat back into the room while still letting in heat from the sun. The panels are frameless with polished edges and fit discreetly within the batten slips to which they are attached using adjustable hinges. Glass Shutters are easily opened to allow access to the window and magnetic catches hold them in place when closed. By choosing an appropriate style, the panel edges can be made to coincide with the glazing bars. This minimizes the visual impact of the panels from inside while making them virtually invisible from the outside. There is a gap of 3mm approximately around each shutter and a tolerance level of 2-5mm.


A report on the Development and thermal evaluation of a secondary glazing system by the University of Ulster, Centre for Sustainable Technologies, found a 40% improvement in the thermal performance of a single glazed sash window when Glass Shutters were used.

Roller blinds can be accommodated behind the Glass Shutters and existing wooden shutters can still be used.  We can provide detachable knobs with concealed ring pulls for these if required.

In some areas, planning consent may be required and we advise customers to seek advice from their local Planning Authority.

Glass Shutters provide:

  • added comfort from reduced heat loss;
  • an elegant design which compliments your period features;
  • the benefits of secondary glazing while still allowing easy access to your windows.


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