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.