Many of the homes in Stoke Newington have single glazed sash windows. These leak heat very readily, both directly through the single pane of glass and through gaps around the frame.
Double, or even triple glazing is the most effective solution to this problem. The multiple panes of glass are separated by a sealed gap filled with air or a dense gas such as argon. By completely sealing this gas you get very little movement and this reduces heat transfer.
Air is a very good insulator, as long as it isn’t allowed to move too much, because it is a poor conductor of heat. If it moves, it will transfer heat across a gap through convection. This is exactly how a wooly jumper keeps you warm – the fibres keep pockets of air stationary, keeping the heat in. Argon works even better because it is denser than air and movement is further reduced.
While multiple glazing is the most effective solution (and one we’ll go into in more detail), it’s also a pricey solution and if you live in a conservation area, it may not be an option open to you.
A cheaper solution, and one that doesn’t change the outside of your home, is secondary glazing. This is not as effective as multiple glazing but it does make a substantial difference. By fitting an additional pane of glass or perspex on the inside of your window you save energy in two ways: you cut out the draughts coming in around the frame and the additional pane of glass traps a layer of air that acts as an insulator.
Secondary glazing is often removable, so you can fit it during winter and remove it during the summer. Other types are fixed permanently, opening like the window they are covering.
In part 2 we’ll take a more detailed look at different types of secondary glazing, but before I go, here’s something I haven’t seen before: DIY magnetic secondary glazing. You get a reel of steel tape and a reel of magnetic tape, each with adhesive on the back. You fix the steel tape to the window and the magnetic tape to some perspex.
Does anyone have any experience of this? Seems like it might just work… Would the strips look odd? Maybe if they made the strips white they could merge quite nicely with your window frames.
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My neighbours have done this. I’ll have to pop up and see what the window looks like if the perspex is removed. The whole thing looked remarkably neat. It was a DIY job in their case. We have large, single glazed, sash windows – it looks like a really good solution.
We’ve gone with the cling-film type secondary glazing this year. However, because there is quite a big gap between the plastic film and the window, and the windows are draughty (or were), perhaps there is still quite a lot of convection air loss going on. I think we will do the perspex treatment for next winter.
Hi Alison thanks for the info. I’ve picked up a length of the magnetic strips so will be giving it a shot. If you want to try it out, let me know.
Hi .
I am thinking of this magnetic perspex secondary double glazing for sash windows after being frozen this winter .
I would love to come and view this if anyone has actually done it and doesn’t mind me coming to have a look. ?
I live in E9 but am happy to come to N16
Thank Lois
Hi Lois
We haven’t fitted it yet but will do soon hopefully. I have a long reel of the magnetic strips and you can pick up sheets of perspex cut to any size for £1.50 per square foot from General Woodwork Supplies (the builders merchants on Stokey High Street).
Btw I snipped out your email and tel but I’ll send you an email now.