How to Fit Double Glazed Windows

Double Glazed home Windows

Fitting double glazed home windows on your own is a great way to save money on an otherwise pricing installation. However, if you don’t know how to do it properly you’re going to end up doing a lot more damage than good to your home. It’s quite likely that you’ll end up needing to spend a lot more money repairing damage you’ve caused or you may end up wasting money on materials that become useless through misuse.

Here at Double Glazing on the Web, we absolutely recommend going to a professional for your double glazing needs. They’ll have the know how, the tools and the insurance to cover any problems that may come with your new installation. We provide quotes and competitive price comparison from across the industry and a wide range of installers to ensure that you’re getting the best price for your project.

If you do want to give it a go yourself then you’ll be wanting to follow these basic steps to ensure that you get it right!

Getting approval

Any time you’re doing any official work on your home you’re going to need to get approval from the local authority by apply for Building Regulations. Once you’re accepted you’ll need to have a specialist supplier carry out a site survey on your property. This isn’t too expensive but is a sound investment as they’ll ensure that any products you purchase will be up to standard according to the building regulations, which will cover energy efficiency, ventilation and a whole host of other factors. Furthermore, all of the measurements and specifications will be the suppliers responsibility, so you can be assured that you’re getting the right stuff throughout your purchase.

Getting the measurements right

It’s going to save you a lot of time and money if you make sure that you’ve got your measurements right the first time around. Follow these easy steps to ensure that you get the correct materials for your installation:

  1. Make sure you’re measuring from frame edge to frame edge, not just the size of the glass as you’ll be fitting an entirely new unit instead of just replacing glass.
  2. Be sure to measure in milli-metres instead of inches for a much more accurate interpretation of the needs of your project.
  3. Measure the thickness of your window. Most installations come in 4-12-4 which is two panes of 4mm glass with a 12mm gap between them, however if your unit is going to require something thicker, you’ll want to know that before purchasing supplies.
  4. Double, triple and quadruple check your measurements. And then check them again! Honestly, you can’t check them enough. It is also good practice to get a window that might be slightly to small. If the window is just too small you can fill the space with plastic packers. If it’s too big you’ll need to buy an entirely new unit.

Installing the double glazed window

Now onto the main event! Make sure to take your time and not rush anything. If you do start rushing you risk causing excessive damage to the walls which is going to halt the entire process and bump the costs up significantly.

  1. Unscrew the current window and cut the sealant surrounding it with a Stanley knife.
  2. Remove the window gently with a pry bar to pull it out from the wall. Very important to not rush here because this is the moment where your wall can get damaged.
  3. Remove the window frame with a soft rubber mallet or something similar. This should come out pretty easily so no need to really bash it.
  4. Once it’s all out, scrape the remaining sealant from the brickwork so it’s clear and ready for the new window!

It’s usually good to take a break at this point and just make sure that everything has gone well so far. Going over the wall to make sure there’s no damage, making sure your new window is up to spec, things like that. Once you’re ready, it’s onto fitting the new window!

  1. First thing to do is capping the sill. Use some super glue to attach the sill endcaps to the window before it’s installed into the wall. Once you’ve done that, use the screws to fully secure it. Make sure to use a sealant as well to protect it from water.
  2. Lift the window (gently) into the wall space to ensure that it fits. If it’s too big, then you got your measurements wrong. If it’s too small, use the plastic packers we mentioned to fill in the gaps.
  3. Use a pencil and drill to mark the pilot holes so you don’t break the window when you’re screwing it in. You’ll want two screws on each side, top, bottom and side to side. Pop some sealant in the pilot holes to ensure water can’t get in.
  4. Next up insert the double glazing into the window by inserting the snap glazing platforms into the corners. Once they’re in, fit the panes of glass snuggly into the frames and use the silicon caulk to seal the edges of the window

Hey presto! You’re finished! This is only a rough guide to installation of course and we still maintain that having a professional perform the service is going to minimise any risk to your homes and potentially save you money from damage or wasted materials.

If you would like to get a quote from us, please feel free to use our pricing tool! We look forward to hearing from you.


In the end, becoming double glazed home windows in your personal space can be a fee-powerful solution, but it calls for cautious planning, accurate measurements, and a methodical technique to make a successful installation. While it’s miles feasible to do it yourself. We strongly advocate seeking the assistance of a professional double glazing installer to reduce the risk of harm to your own home and to make certain that the installation is performed efficiently. 

By obtaining fees from respectable installers through our pricing device, you could compare charges and locate the fine deal to your double glazing challenge, supplying you with peace of mind and a wonderful installation.


What are the advantages of installing double glazed home windows? 

Double glazed home windows provide numerous blessings, inclusive of advanced electricity efficiency, decreased noise pollutants, extended domestic security, and more desirable belongings price. The insulating properties of double glazing assist to maintain your private home warm inside in the winter and funky in the summer season, leading to decreased electricity payments and a greater snug dwelling surroundings.

How much can I expect to save via putting in double glazed home windows myself? 

The quantity you can keep by installing double glazed home windows yourself varies depending on the size of your mission and the price of a professional set up to your region. On average, you will be able to keep between 20-30% of the full fee via doing it yourself. However, it’s far crucial to weigh the potential financial savings towards the risks of wrong set up and damage to your private home.

What gear do I want to install double glazed home windows? 

To deploy double glazed home windows, you may need a range of gear, along with a measuring tape, a Stanley knife, a pry bar, a gentle rubber mallet, a screwdriver, a drill, a caulking gun, and a glazing tool. It is critical to make certain that you have all the essential equipment and substances before beginning your mission to avoid delays and further prices.

Can I install double glazed home windows in an indexed building or conservation region? 

If you stay in a listed construction or conservation region, you may want to acquire unique permission earlier than installing double glazed home windows. It is essential to check with your neighbourhood planning authority and observe any specific pointers or regulations that observe your house. In a few cases, you will be required to install historical past-fashion double glazing that suits the present window style and substances.

How long does it take to put in double glazed home windows? 

The time it takes to put in double glazed home windows varies depending on the scale of your project and your stage of enjoyment. On average, it can take between 1-2 days to put in a single window, assuming you have got all of the important gear and materials. However, it’s far important to allow greater time for preparation, measurements, and cleaning up after the set up is entire. If you are uncertain about your capacity to finish the project efficiently, it is better to hire an expert installer to avoid delays and make certain a first-rate result.

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