Single Double Glazed Window in Cornhill-on-tweed

It depends on a few factors whether a new double glazed window will look different to existing ones. If your existing windows are very old, perhaps 10 years or more, then it’s likely that there will be some small differences.

The first thing to remember is that your double glazing is exposed to the elements as soon as it’s installed. So over time, unless you’re very good at cleaning and maintaining your windows, they’re likely to look a bit dirty. Window frames that are south-facing may also become slightly discoloured from the sun, so if you install a new window right next to it you might notice a difference.

Also, there have been lots of technical advances in windows over the years. If your existing windows are significantly older, you might notice a difference in the handles on openers, and if your existing windows were installed before 2010 they might not have trickle vents, which is an extra strip on the inside of your window to keep air flowing through your home. While it’s not a legal requirement for replacement windows to have trickle vents if the original one didn’t, it’s a good idea to have them installed as they help prevent condensation and mould.

The only truly noticeably different elements to a new double glazed window compared with existing ones are likely to be on the inside, which might not be a problem for you if you only have one window in a room. However, if you know the brand of your existing windows, you can ask your window installer if they can source the same ones. Even if they’ve been updated slightly, the difference should be minimal.

Unfortunately, you can’t fix the glass on one side of a double glazed window. That’s because they’re sealed units – once one pane of glass is broken, that will break the seal and its thermal insulation properties will be lost.

The good news is that if your window frame is still looking great, there’s no need to replace that. You can simply replace the glass in the window, which will cost much less. You can look to spend around £250 on a sealed unit, whereas a whole replacement single window may cost up to £600.

When an installer comes to replace the glass in your double glazed window, they will survey the inside and outside of your home around the window, then move any furniture by the window so they’ve got access. They should then pop a dust sheet down to stop any debris from getting on your floor.

Then, the installer will carefully remove the beads from the frame. They will then lift the glass out of the frame and put it somewhere safe before cleaning out all of the dust and any debris that has found its way into the frame. Using spacers at the bottom of the frame, the installer will make sure that the sealed unit is square in the frame to get a good fit. Once they’re happy, they will replace the beading and make sure it looks perfect before cleaning up their tools.

You could have a go at replacing the glass on a double glazed window yourself, but it’s not recommended. Leave it to the professionals who will know exactly what to do and will be able to do it quickly and safely.

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.