Find a Window Installer you can trust in Merriott.

If a window is double glazed, it has two panes of glass that have a space between them containing argon gas. The gas works as an insulator, keeping heat inside the house as well as reducing noise. It also strengthens the window.

On the grand scale of things there isn’t a huge difference between B-rated windows and A-rated windows. Consumer watchdog Which? have calculated an extra 6.5% would be saved on energy bills with A rather than B rated panes. Be aware that A rated windows are slightly more expensive, however.

Most window installers will be able to provide you with one double glazed window and fit it for you. If you’re replacing one double glazed window in your home, ask them to try and source the same windows that you already have or find one that’s very similar. Externally, you probably won’t be able to notice the difference, but if your existing windows are very old there may be some exterior discolouration and the locks and handles might look slightly different.

If you want one double glazed window so you can fit it yourself, there are lots of online companies that can supply you with one window. However, window fitting is a skilled trade and you might want to consider whether you have the right tools and experience to fit it yourself. Of course, you’ll save money on installation costs, but if something goes wrong, you might end up shelling out to get it fixed anyway.

The other thing to consider is that any replacement windows need to be certified that they meet Building Regulations. If you fit the double glazed window yourself, you’ll need to apply to your local council building control officer to get a certificate that confirms that you fitted the window within the regulations. You’ll have to pay a fee for this, and it will be even more expensive if Building Control say that the window hasn’t been fitted within the regulations and you have to start again.

The alternative is to ask a reputable window installer that is registered with a self-certification scheme, like FENSA, to install the window. That means that they can self-certify that the window meets building regulations once they’ve finished the installation.

As well as keeping your home warmer and reducing noise, you’ll notice a saving on your energy bills from installing double glazing. If you install A++ rated windows in your home after having single glazing, you could save up to £120 year on your energy bills. The Energy Saving Trust has more information.

Double glazed windows are better than single glazed generally because they are more energy efficient. The clue’s in the name – double glazed windows have two panes of glass while single glazed windows only have one. In double glazed windows, there is a space between the two glass panes. This space is filled with inert gas or a tight vacuum, which helps to provide an extra level of insulation. That means that heat won’t escape your home easily, nor will it creep in, so you can keep your home at a more comfortable temperature.

The extra pane of glass also helps to increase your home’s security. Single glazing is pretty easy to smash through, whereas it will take much more effort to smash double glazing and will create more noise, so burglars might be put off.

Another reason why double glazed windows are better than single glazed ones is that they help to reduce noise. Of course, if you live by a busy road you’ll still hear some traffic noise, but it can be significantly reduced buy double glazing. In the same way that the inert gas in the middle of the two panes keeps heat in and the cold out, it also helps keep noise out.

With double glazing, you’ll also notice much less condensation. With single glazing, it’s common to see condensation on the inside of the windows, especially when the heating is on. This is because the outside of the window is cold, but the inside is warm. With double glazing, the insulation between the two panes stops there being such a difference in temperature between the inside and outside of the window.

Yes, of course! It’s common for people to replace just one double glazed window. One reason that people want to replace one window is that the sealed unit inside has failed. You’ll know if this has happened because you’ll be able to see condensation on the inside of glass, which gets frustrating because you can’t wipe it away. In this case, you can choose to simply replace the sealed unit or the entire frame, which you might want to do if it’s looking past its best.

When you’re replacing just one double glazed window, if you know the brand of your current windows you could ask your installer if they can source the same ones. This will help to keep them looking as similar as possible, although if your existing windows are very old you may notice some discolouration on the exterior compared to the new one, and locks and trickle vents might look different.

Replacing just one double glazed window shouldn’t take a qualified window fitter long, and could cost as little as £400. If you want to simply replace the sealed unit, that may only cost around £250. You could try to fit a new window yourself, but it’s worth bearing in mind that all replacement windows need to be certified that they’ve been installed to meet building regulations, so you’ll need to apply to your local building control officer who will come and inspect the work then issue a certificate. If you ask an installer who is registered with a self-certification scheme (like FENSA) to fit the window for you, they can issue the certificate themselves when they’ve finished the work.

• Impact from a stone or other object smashing the glass in a ‘bullseye’ effect
• The result of a break-in
• Extreme weather or changes in pressure causing a crack
• The sealed unit being ‘blown’, meaning that it’s no longer energy efficient due to air leaking out

Accidents happen, and sometimes windows get broken. And that will lead to you wanting to replace just the glass in your window, rather than the whole frame. Also, as windows get older they can mist up on the inside, which means that the unit has ‘blown’ - so you’ll also need to replace the glass. But how much is it to replace the glass in a window? Luckily, if the frame of your window is in good condition, there’s no need to replace it, and this will reduce the cost. For an installer to fit a new pane of glass in a single glazed window, the average cost is £100, while a replacement double glazed sealed unit will cost an average of £110. Of course, as this is an average, if your window is very large you may spend more, and if your window is very small the price may be less. That's why it’s important to get a range of quotes so you can compare costs and get the best price. If you’re good at DIY, you may feel confident enough to have a go at replacing the glass in your window yourself. In that case, the cost of sealed unit and any other materials you need will cost an average of £57. It’s a significant saving, and if you think you can do it, then give it a try. However, if you’re in any way unsure, it’s best to leave it to the professionals. A window installer will be able to replace the glass in your window in less than an hour. Even though it costs more for a professional to do it, if you get it wrong and have to start over it will cost you more in the long run.