Sash window draught proofing VS Double glazed sash windows
- Minus the sales pitch
Firstly let us first distinguish how heat is lost in the home, regarding windows at least that is anyway.
To do this we first need to understand the difference between draught proofing and double glazing, please forgive me if I come across as condescending to some but many people who feel the cold and experience huge heating bills in winter fail to realise that the two things are in actual fact completely different and work in entirely different ways.
Draughts are essentially gaps or cracks that ultimately allow either the cold air outside in or your expensive warm air out! And as the reader is no doubt aware, old sash windows can have many gaps and cracks due to the nature of their functionality.
Double glazing on the other hand is not there to combat the draughts.
I’d like to give you an exlanation that should help you to understand just how double glazing helps keep the home environment warm.
Let us think about how a radiator works to warm the home, basically the metal radiator fills with hot water drawn from your boiler thus creating a warm metal surface that in turn radiates this heat throughout the room, increasing the temperature to a desirable level for comfort.
Now, let us go back to your single glazed windows.
Let’s say the outside temperature is freezing, this cold air hits the outside surface of your single glazed window reducing the temperature of the glass. This cold surface is also facing into the room the window is in. So you now have a window working in exactly the same way as your radiator although in the opposite direction. You can now imagine why the bills would be quite high as the radiators warming effect and the interior glass surface cooling effect neutralise one another.
Double glazed windows effectively provide a thermal barrier from the exterior glass surface to the interior glass surface preventing the outside temperature from negating the warming efforts of the home owner.
With this information you can see that (as I have seen far too many times before) double glazed windows are great but if they are fitted in a frame that is not well insulated then the purpose for which they were intended will not be achieved.
Our strongest advice is always draught proof your windows first before going head on with double glazing. In many cases once the windows are draught stripped and serviced you will see a huge difference.
If after you have the windows draught proofed and you want to go the extra mile then the procedure is still quite simple, if not a little more expensive, as you need only to have new sliding sash windows made up with double glazed units installed and they can be retro fitted into your already insulated box sash frames.
You would be surprised the amount of box sash windows I see on an all too regular basis were previous workers or so called specialists have fitted double glazed timber windows into the original box but have failed to fit draught proofed beadings.
This is as far as I am concerned, complete madness as the double glazed windows will only ever work as they were intended if fitted into a well insulated frame.
"Essentially if you have sash windows that are rattling and draughty then here lies your main problem and the cost of draught proofing is far cheaper than double glazed replacements too!
With a full box sash window comprehensive mechanical service and overhaul coming in at around £300 (give or take depending on who you go to) and full replacement of the box with double glazing upwards of £1800 it really is a no brainer.