Small fanlights from bungalows cost about $200 to fix, but Wiki says it is not uncommon for the repair bill to reach $40,000 for large homes which have numerous stained glass windows and big panels in places such as entranceways and stairwells.
Ratcliff, who previously worked at the Victoria & Albert Museum in London doing glass restoration, says many home owners are unaware of damage to their leadlight windows because the glass is unbroken.
"If you compare stained glass to bricks and mortar, it's the mortar that gives up and the bricks come tumbling down. It's the same with leadlight and stained glass windows; it's the lead that gives up. If you look at the solder joints you'll find fine hair line cracks, so instead of lasting 70 years, windows might only last another five or 10."
Ratcliff says stained glass windows are part of the appeal of character buildings and it's important not to overlook their value. "They are a selling point; they're what make a house special. You hear people say 'I saw the windows, and that was it, I had to buy it.'"
Ratcliff says antique coloured glass is in short supply and she is distressed by the number of windows going to the dump when glass from them could be recycled for repairs to other damaged stock.
However some insurance companies are coming to the party in helping to preserve the city's heritage by paying for the restoration of windows taken from red stickered homes for installation in rebuilds.
"We have taken out the leadlights and quoted for restoring them and turning them into triple glazed units."
The Glass Room uses specialised cutting equipment imported from Europe to remove entire windows from masonry and wooden buildings such as churches. Even very fragile glass can be removed successfully and Ratcliff says and work on St Paul's church in Madras Street was a case in point.
"We took two millimetre thin glass out of stone without a single breakage. Everybody including the Historic Places Trust said it couldn't be done. All the suits lined up watching and waiting and couldn't believe it, but we have a really well trained team."
The Glass Room has offered to help with the removal of stained glass windows from Christ Church Cathedral as the building is de-constructed and is awaiting a reply from the Anglican Church.