Preserving heritage glass while repairing old windows

Some heritage glass is so fragile (and valuable) that most people are too afraid to repair it. We can help.

It’s common to have beautiful decorative glass in old windows – especially in stairwells of high quality Victorian homes. 

The trouble is, the glass in these windows is so valuable, and so fragile, that most people are afraid to even attempt a repair. A single pane can easily cost $1,800 to replace. Instead of risking it, people do superficial repairs or avoid doing them at all. 

A century of avoidance and neglect means that these windows are often in worse condition than any other window in the house. The avoidance doesn’t work – the longer the repairs are neglected, the higher the risk that glass will be broken during repair. 

How do you protect heritage glass while doing extensive high quality repairs to the timber around it?


Glass like this can easily cost $1,800 per piece to replace.

First, mouth-blown glass is imported from France. The glass is cut to size, and patterned with a matching design. It might be acid etched or lacquered. It is then sand blasted and finally installed.

The key is to completely remove the glass – safely – before any repairs are done. 

That’s exactly what Sealasash did recently with these beautiful windows in a Richmond mansion. All the glass was safely removed, which enabled us to properly remove all rot. Then, once all the repairs were done to a high standard, we re-installed the glass. 

We were delighted to take these beautiful windows and bring them back to life – keeping all the heritage character, doing all the necessary repairs, and improving performance with premium draught seals. 

If you would like to talk to a timber window expert who understands all your options, and who will listen to your priorities, then please don’t hesitate to contact us.

Looking for double glazing for your sash windows or wooden windows?

Sealasash can double glaze your old timber, wooden and sash windows with new high-performance glass.  We also upgrade windows to include draught and acoustic seals that further improve the comfort and energy efficiency of your windows. 

Learn more about Sealasash:


Vacuum Insulated Double Glazing

Our ultra-high performance double glazing fits perfectly within your existing timber work, eliminating any bulky or expensive modifications.


Fix Those Annoying Rattles

With our draught and acoustic seals you’ll achieve amazing new comfort levels by reducing infiltration of outside air, noise and dust without the annoying rattles.

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Using traditional craftsmanship and modern materials, we’ll restore your windows and make them better than new.  This includes high-performance double glazing and draught seals that will dramatically improve the comfort and energy efficiency of old timber, wooden and sash windows.