Triple-glazing sash windows

Triple glazing sash windows were long considered the most energy efficient window option. However, advances in glazing technology have challenged this notion.

Vacuum double glazing provides superior insulation compared to standard triple glazing.

Additionally, vacuum double glazing tends to be thinner and lighter than triple glazing.

This makes it an ideal retrofit solution, as it can be installed directly into existing window frames without the need for costly frame replacements.

triple glazing sash windows near me
Triple-glazing sash windows

Reglazing windows with VIG glass to achieve triple-glazing efficiency

triple glazed sash windows vig glazing
Listed building secondary glazing

Keep your existing sash windows with VIG glass

Our reglazing service lets you keep your wooden sash windows rather than pay for costly full window replacements.

  • Retain the original character and aesthetic of your home’s windows
  • Avoid the high cost of full window replacement.
  • Enjoy better energy efficiency than triple-glazing.
  • Reduce outside noise entering through windows.
  • Improve comfort and cosiness.
  • Enhanced security. More difficult for intruders to break through two panes of toughened glass.


An extensive guarantee covers all elements of our reglazing service, providing peace of mind.

8 Years of paintwork guarantee

Guarantee on paintwork

Guarantee on VIG glazing

Guarantee on repairs made with Accoya

Cost considerations

The reglazing of typical sash windows with toughened vacuum insulated glass (VIG) double glazing, draught-proofing, and restoration of the frame and sashes costs approximately £1500-1700 per window on average.

This is comparable to or even less expensive than high-end listed building secondary glazing.

However, VIG double glazing provides all the benefits of modern thermal performance and noise reduction while retaining the original appearance.

Sash window repair reglazing prices

What’s included

Double glazing retrofitting

Double glazing retrofitting

Supply and installation of Vacuum Double-Glazing

Double glazing retrofitting
Window frame restoration

Window frame restoration

Restoration and rot repair for window frames and sashes

Window frame restoration


Installation of draught-proofing seals



Painting of wooden window frames


Visual proofs of high-performance window insulation

Detailed thermal photographs displaying the reduction in heat loss.

VIG glazing is more efficient than standard triple glazing.

Learn more

Customer testimonials

Triple glazing efficiency but slim enough to fit existing sashes

Triple glazing compared to vacuum double glazing

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