Households choosing to replace their windows with energy efficient products could save up to £155 a year.
If you’ve ever seriously looked into making energy efficient improvements to your home, one of the steps you’ll be encouraged to take is to replace the windows. Furthermore, if you’re buying a new home, the best advice you’ll receive is to put double glazing right up there on your list of essential must-haves, along with a decent boiler and insulation in the right areas. This is because windows can make a significant difference to the cost of heating a home.
Poorly maintained, faulty or single glazed windows all allow heat to escape from your home, meaning you have to keep the heating on for longer in order to maintain a comfortable temperature inside. This is a real waste of both energy and your money, so it may be time to find an alternative.
What is an energy efficient window?
When people talk about energy efficient windows, they usually mean ones that are double or triple glazed. Double glazed windows consist of two sheets of glass, with a very small gap (usually around 16mm) in between. This gap is crucial, as it provides an insulating barrier to keep the heat in. Some types of double glazing have a layer of gas in this insulating gap for extra efficiency.
Triple glazing works very much in the same way, except with three layers of glass. Not all triple glazing is more energy efficient than double glazing, but the way to check with any window is to look for its BFRC (British Fenestration Rating Council) rating.
Window ratings – what to look for
When shopping around for new windows, it can be difficult to know what to look for. Some glazing manufacturers use different rating systems to mark how energy efficient their products are, which can make the process rather confusing. Here are the main ratings and specifications to look out for:
• BFRC ratings – The BFRC rates windows by taking into account the whole frame and the glass, using a scale from A+ through to G. You may have seen something similar on Energy Performance Certificates for properties as a whole, as well as energy ratings seen on appliances such as refrigerators and washing machines. An A+ rating really is exceptional, while a G rating is the least efficient and is not recommended as the best choice.
• U-values – This is another specification you may spot when looking for new windows, and it refers to how easily heat can pass through the material. Windows with lower u-values are the ones to look out for, as they indicate better insulation and lower heat loss.
• Low-E glass – Standing for low emissivity, glass marked as Low-E often has an invisible coating of metal oxide to let the light in but stop heat from escaping.
It’s not all about the glass however. The space between the two panes of glass in double glazing also determines how efficient it is. Look for windows with ‘warm edge’ pane spacers containing little or no metal, as these are usually the most efficient.
The frame can also make a difference on the environmental impact of the window. For example, uPVC windows last a very long time, require little maintenance and can be recycled, whereas wooden frames are low impact in terms of their manufacture but can affect the efficiency (as well as the appearance) of the window if they are not regularly maintained.
How much could I save by replacing my windows?
Before going to the expense and effort of buying and installing energy efficient windows, it’s only natural to ask – is it going to be worth it? The good news is that replacing single glazed windows with double glazing is nearly always a good idea, and will save you money on your heating bills each year. How much you can save depends on the BFRC rating of the windows you choose and what type of property you own, as well as its size and the number of windows it has.
Let’s take a look at a few examples, using figures from the Energy Saving Trust (applicable to properties in England, Wales and Scotland):
• A typical detached house getting A-rated double glazing fitted could save between £120 and £155 a year, while semi-detached properties could save between £80 and £110
• Bungalows and flats could save up to £75 and £55 respectively with new A-rated windows
• Even properties getting C-rated double glazed windows fitted could save up to £135 (detached), £95 (semi-detached), £75 (mid-terrace), £65 (bungalow) or £50 (flat) per year
Some of these costs may not seem very much compared to the cost of the windows, but it’s important to take more of a long-term view in order to see the true savings.
So, for example, if you replace the windows in your mid-terrace house with long-lasting, durable uPVC double glazing marked with an A-rating, you could save up to £425 over five years or £850 over ten years. If you had a detached house, these savings could be as much as £1,550 over ten years. Looked at from this perspective, most people would agree that replacing windows with double glazing is well worth doing.
More benefits of double glazing
The potentially lucrative savings aside, it’s not all about money. There are lots of other reasons to upgrade to energy efficient windows, starting with the fact that they make your home far more comfortable and pleasant to live in. Even if you don’t care much about saving up to £155 a year, most people would appreciate being warmer, having fewer draughts and ensuring that their families enjoy more pleasant living conditions. As an added benefit, double glazed windows can reduce condensation, which you may notice builds up on your current windows.
If you care about your carbon footprint, energy efficient windows are an ideal way to limit your environmental impact. Double glazing not only keeps the heat in, but it keeps the noise out. It can reduce road and rail noise, giving the occupants of the house the benefit of lovely peace and quiet.
Double glazing can also offer added security to a property, as well as making it far more saleable in the future should you ever choose to move.
