Is it worth getting double glazing?

Double glazed windows are the most popular choice of windows for homeowners in the UK and the benefits are well proven:

• The weather has a lot to answer for here in the UK and for this reason, being more energy efficient is necessary to keep us dry and warm. A+ double glazing can save up to an average of £145 a year on energy bills.
• Double glazing can make our homes healthier environments as it reduces the build-up of condensation on windows and the growth of black mould.
• If you live in a noisy area, noise reducing double glazing can significantly reduce the background noise and help you get a better night of sleep.
• What really makes double glazing worth it is the increase in property value you can expect and the long-term payback of reduced maintenance costs.

How the window frame style affects the average cost of double glazing

Casement windows

This is the standard style of window that has been fitted in the UK for hundreds of years. Casement windows open on a side hinge with either one pane opening or a pair.

The average cost of double glazing for a white uPVC casement window ranges between £600 to 1,800 depending on size, glazing design and how many are being replaced in the property.

Sash windows

A beautiful and aesthetically pleasing window that can add significant value to a house. A sash window has two framed panels that slide up and down over each other.

Most often fitted in period properties and around London, many listed buildings are required to have sash windows.

The cost to double glaze a sash window is usually 50% more than a casement window.

Tilt and turn windows

The Tilt and turn window has become a hugely popular style for uPVC and aluminium windows because they can be securely left open for ventilation by tilting them inwards whilst remaining fully locked.

The cost of double glazed tilt and turn windows is usually 25% more than a casement window.

Bay windows

Bay windows extend out from the room and because of this, you require three windows instead of one.

Great for letting in lots of light and giving extra space in your living space a bay window gives you panoramic views from your house.

The cost of a double glazed bay window can be up to 150% more than a casement window.

How the window material affects the average cost of double glazing

Apart from the style of a window, the material for the frame used also impacts on the average cost of double glazing:

uPVC windows

Unplasticised Poly Vinyl Chloride, otherwise known as uPVC, has been one of the most popular choices for double glazed windows in the UK since the eighties.

uPVC double glazing is thermally efficient, low maintenance and secure. It's also the most economical material for windows.

The average cost of double glazing for uPVC casement windows is between £600 to 1,800 depending on size, glazing design and how many are being replaced in the property.

Aluminium windows

Another easy to maintain window frame choice that's popular for it's slimline appearance.

Aluminium isn't as thermally efficient as uPVC but does offer a contemporary look and most often used in modern properties.

The cost of double glazed aluminium windows is 25% more than uPVC but 25% less than timber frames.

Timber windows

Nothing beats the look of well-maintained wooden window frames. A quality hardwood window is a good investment for a home and can add significant value, especially in period properties.

The oldest material choice of windows, timber frames can last for years if they are well looked after, but they are high maintenance and need a lot of attention.

The average cost of wooden double glazing windows is 25% more than aluminium and 50% more than uPVC.

Other options that affect how much double glazing costs

Apart from the style and material of a double glazed window, there are other factors that will impact on the cost of new double glazed windows.

Size - it might seem obvious but a large living room picture window is going to cost significantly more than a small toilet window.

This is the main reason why it's so difficult to answer the question of how much does double glazing cost.

Energy rating/quality of glass - glass might look all the same but there is a huge difference between the quality of energy efficiency performance.

When buying new double glazing look at the thermal efficiency, the solar gain and the air leakage values. A window rated A++ is the highest rated across all of the above and should be what you choose to make the investment in double glazing worth it.

Furniture and finish - door handles, locks, number of opening windows, colour and any grain effects all need to be factored into the double glazing cost.

Cheap windows might not include extras and you will need to pay more for upgrades to get the handle or locks that you want. Don't underestimate how much the finishing touches can add to a basic price.

When should I replace my double glazing?

Replacing a full house of 8-10 double glazed windows is an investment that will cost several thousand pounds and is a big decision for most people.

We would never recommend for you to replace windows that are in perfectly good condition without any issues. However, it does get to a point when your windows are letting the property down and you would be far better to take the investment.

• Draughts - the main reason to change windows is that your old ones are letting in considerable draughts and cold which can seriously push up your energy bills. Double glazing seals can fail so if you can feel cold blowing around the edge of the window it might be time to change them. Or, your original windows may have been badly fitted with lots of expanding foam around the edges to make up for a poor fit. If this is the case, we would recommend replacing.
• Warped frames - older cheap uPVC can warp and discolour leaving windows that look tired and shabby. Warped windows can also cause issues with gaps around the edges letting in cold air. If your white windows are now the colour of sour cream then it could be time to upgrade.
• Condensation - if you have condensation inside the double glazing it indicates the seals on the windows have failed. If you have this problem the only real way to solve it is to replace the windows. Check with your installer or manufacturer as they might be covered under warranty.
• Desiccant - this is where you have bits inside the glass caused by the seals failing.
  As with condensation, the only way to solve this permanently is to replace the units with failed seals. Again, check your warranty and guarantee.