Double glazing existing sash windows to save money on new joinery

Sash windows that are over a hundred years old are so well built, that in some cases double glazing them is actually possible without causing any issue to the structure of the sash itself. When this upgrade is possible, thousands of pounds can be saved in joinery costs, as well as maintaining beautifully slender and elegant period character. The advantage of this service to Mansion Blocks and conservation areas is game changing. They now have an option to make their leaky old Victorian properties warm and comfortable. With so many sash windows concentrated in London, there’s even council guidance to get you started.


What is the double glazing of existing sash windows?

You might be wondering how double glazing original sash windows is possible, after all they only have a rebate for a single glazed sash window. How can we possibly convert a window for double glazing? Well the secret to double glazing original sash windows lay in the thickness of the sash. We don’t need to concern ourselves with how small of the original rebate for glazing is, just how much timber will be left overall after the rebate is cut deeper for a double glazed unit, and that it will result in a sash that is still structurally sound. This is not good value if you cut so much of the sash away that it causes structural issues and for this reason James Gaskin of London Sash Window Repairs Ltd comments “To get a sash window double glazed nicely using the existing joinery, it’s a must that the original sash window is 38mm or more in depth. Any less than this results in cutting into the original mortice and tenon which would structurally compromise the original joinery and that just won’t last. A sash needs to be structurally good when we’ve cut the rebate, not with the glass as support, and of course you wouldn’t do any of this without a quality sash window draught proofing system to close up the gaps around the old frames’.

While other companies favour the replacement of sashes so that the mortice and tenon can be offset which will ultimately lead to a stronger product, as some homeowners will find out, especially those in Mansion Blocks where like for like is imperative, the replacement option just isn’t there for them. The rules just won’t or can’t accommodate for new joinery, however accurate the replica is. Lambeth council provide a brilliant resource for external alterations which will help clear up some of the myths and facts behind sash window replacement and alteration to the look of a building.


How much money can I save compared to replacement windows?

The amount of money that can be saved double glazing original sash windows is almost fifty percent of replacement. If you are a keen DIY enthusiast then it really is fifty percent as you can decorate after have the professional double glazing original sash windows company come in to make the carpentry alterations and repairs. Whilst the plastic, the plague of almost all landfill sites to date is cheaper than wood, it still isn’t cheaper than double glazing original sash windows. This means that pound for pound you simply cannot find a better service to keep your home comfortable and also improve the value. Double glazing original sash windows carries an additional benefit of improving security and also may help to lower your contents insurance when fitted with high quality security restrictors.

Overall it’s fair to say that if you like looking after your property, then treat them to double glazed sash windows, but bare in mind being sympathetic and using the original joinery isn’t a cheap shortcut, it’s just a fortunate byproduct of the high quality joinery that might be as much as 130 years old that was carefully made by committed craftsmen, and what a shame it would be to throw away their hard work!

    Leave a Reply