One question we often get asked at the Conservatory Hub is whether it’s better to spend a little more money and go for the most energy efficient windows or if a cheaper option will do just as well. To answer this, you need to understand what energy efficiency means with regards to double and triple glazing and how it effects heat loss in your home.
The good news is that energy efficiency is much easier to figure out nowadays. Windows are rated from A+, the most efficient, down to G, the least and you get a certificate that is similar to the ones found on electrical appliances. Any double glazing you have installed should be between A+ and C if you want the right amount of insulation for your property.
Energy efficiency is independently rated by the British Fenestration Rating Council or BFRC. They have actually just begun accepting applications for their new, higher A++ rating which came into effect on 1st October 2015 and should give consumers more choice in the future.
A number of things effect energy efficiency in windows:
- First there is the type of gas that is placed between the panels. Inert gasses such as Argon are far more insulating than normal air or a vacuum.
- Secondly, how the glass is treated is also important. Low emissivity glass has a metallic coating that is so thin that you can’t actually see it. What this does is to allow in natural light but reflect back the heat in your room where the window is installed.
It’s not just the glass of course that is important in your double glazing, there’s also the frame. uPVC is a very popular choice with home owners and businesses as it is fairly cheap. These types of frame are alos very good at insulating. Choosing something like wood is also an excellent option though it does require more regular maintenance and painting.
Low U, High R Values
Window ratings are decided through their U and R Values. A low U value shows that the glass of your double glazing is letting through just a small amount of heat. A high R value is a mark of the overall energy efficiency of the glass.
Cost of Double Glazing
There is quite a big difference between A+ rated windows and C in the price you pay. There is, however, no great difference in the energy efficiency with A+ ones probably saving you an extra £30 to £50 in fuel costs over a year. Companies that try to push the more expensive option without offering you the alternative are, unfortunately, quite common. If your budget is more limited then opting for C rated windows is a chance to save money.
Is Triple Glazing the Answer?
You also have the option to install triple glazing in your home, which is more thermally efficient but naturally costs extra. This is a popular choice in many Nordic countries where the weather is a lot less temperate than here. Perhaps in the north of Scotland you might be thinking about getting triple glazing installed but for those in the south it is not really necessary. Double glazing should work fine and costs a lot less.
Much depends on what you actually want installing and the level of budget you are devoting to the job. To replace all the windows in your home could cost as much as £5-8,000 depending on the type of windows and the installer you choose. It’s worth noting that even with energy efficiency there are opportunities to save money if you have the right information at hand.