Single Double Glazed Window in Llanfairpwllgwyngyll

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.

To install one small double glazed window, it will take anywhere between two hours and half a day. It will depend on whether one installer is fitting your window or two. And if you’re doing it yourself and don’t have any professional experience, it will take even longer.

When the window fitters arrive, they will make sure they’ve got safe access to the window and move any heavy furniture if they need to. Any good installer will lay down a dust sheet, but it’s a good idea to check that they’ve got one laid down before they start.

The first step any window installer will take is to double check the measurements of the new frame against your existing one. Hopefully it should match up, so then they’ll take the old window out. Then, they’ll insert the new frame into the aperture and bolt it into the concrete. They'll check it with a spirit level to ensure it’s even before moving onto the glass sealed unit.

The installer will place the glass into the aperture, then fit the beads to secure the glass in the frame. They’ll then use silicone and trim on the inside and outside to ensure the window looks perfect. You won’t be able to see where they’ve used sealants or trims because they’ll colour match them so it’s not noticeable. Then, they’ll tidy up all of their tools and the working area and let you know what needs to be done in terms of proving that the window meets building regulations. Most good installers are registered with a self-certification scheme, so will be able to issue a certification once the work is complete.

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.