Find a Window Installer you can trust in Dolwyddelan.

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.

How long your aluminium windows will last depends on their quality. They should last 20 -30 years at least, but have been known to stay in good condition for up to 45 years. This is considerably longer than uPVC and wooden double glazing.

After fitting your new windows, your installer should take away and dispose of your old windows. If you want to keep them, just let your installer know before they start work. The UPVC frames are melted down and used on the unseen parts of new windows. Aluminium frames are re-smelted and wooden are broken down and used as chipboard.

Using a Fensa registered installer isn’t compulsory but it helps to protect you from cowboys and rogue traders. It will also make life a whole lot easier in regards to Building Regulations. Replacement windows must meet a certain energy efficiency rating and once fitted you need a certificate to show your installation complies. By using a Fensa registered company they’ll issue this certificate, otherwise you’ll need the council to look at the new windows.

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.

• Climate - If your window faces south, it will be subject to direct sunlight for a lot of the day. This tends to cause the sealed unit to fail more quickly – a south-facing window may last between 10-25 years. This is because the spacer bars will twist as the temperature rises and causes the adhesive holding them together to eventually fail.
• Moisture - Windows in kitchens and bathrooms tend to fail more quickly because they come into contact with moisture more often. For example, if water gets on your windowsill when you shower, the seal around the glass will come loose more quickly if it’s constantly wet.

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.

The energy efficiency of windows is measured using ratings, varying from A, the most efficient, to G, the least efficient. This scheme is run by the British Fenestration Council (BFRC). To comply with Building Regulations you’ll need windows of energy efficiency at least level C.