How Much Does Double Glazing Cost?

Most people agree that it is a wise move to reduce your heating bills. Not only does it give you more disposable income every month, but also it’s good for the environment. The best and easiest method to reduce energy loss in our homes is to insulate wherever we can. However, this doesn’t just mean insulated lofts and cavity wall insulation. Although these are good, they need to be used hand-in-hand with double glazed windows and doors. Furthermore, the cost of double glazing is steadily dropping so the technology is finally worth installing in our homes. Unfortunately, it is very difficult to put a definitive cost on double glazing in your house as there are so many different factors to consider. This article will hopefully give you some idea of the determining price factors and show what kind of ballpark costs you can expect to pay.

Double glazing prices & a detailed breakdown

Detailed Pricing for Double Glazing

This table shows how frame construction material affects the price.

Property Windows installed uPVC Frame Aluminium Frame Wood frame
Ground floor flat 4 £2,200 £2,400 £3,500
House 8 £4,500 £4,900 £7,250
House 10 £6,800 £7,300 £10,900
House 15 £9,000 £9,800 £14,500

The following table shows how style and finish affect the average price for 8 uPVC windows.

Frame Material Style Price
White uPVC Cottage £5,500
Wood Effect uPVC Cottage £11,500
Wood Effect uPVC Georgian £17,300

This table shows the effect of size and style on price

Window Size uPVC Sash Window uPVC Casement uPVC Tilt & Turn
50cm x 50cm £550 to £750 £280 to £360 £400 to £550
100cm x 100cm £650  to £820 £330 to 450 £490 to £650
120cm x 120cm £750 to £1000 £380 to 460 £530 to £690

Installing double glazed windows will reduce your heating bills, but the amount depends on the size of your home and how well insulated it is.

Energy Efficiency Detached House Semi detached House Terrace House Bungalow Flat
A+ £110 £80 £60 £60 £35
A £105 £75 £55 £55 £35
B £100 £70 £50 £50 £30
C £100 £70 £50 £50 £30

These savings, calculated from surveys, show how much you can save on your heating bills every year by fitting double glazing.

Pricing Factors for Double Glazing

Quite frankly, few of us can afford to waste money so it’s important to know when you are being ripped off. Generally speaking, the average costs of a single, double glazed, standard-sized window in the UK falls between £400 and £600. This price will vary, however, depending on the style of window (sliding sash windows cost about twice the price of hinged casement windows) and its construction material (uPVC windows are much cheaper than those with wooden frames). Furthermore, other factors include the type and thickness of glass, frame size and the number of windows installed.

You have probably seen adverts in the media showing special offers for cheap double glazing if you buy a certain number of windows and doors. This is because there are many installation companies that need to continually try to undercut each other. It is, therefore, worthwhile asking around for quotations to find the available discounts. You will also find that double glazing manufacturers often have their own teams of installers whose labour is included in the price of the windows. This is obviously better as they will be specially trained in how to fit their own windows. And furthermore, will cheaper than hiring your own installation company.

Remember, installing a ground floor window is easier than an upstairs window. Generally speaking, an upstairs installation will take longer and needs scaffolding which costs an average increase of about £60 per window. Also, there is a London premium on all work done in the Capital compared to the rest of the country.

Cost calculation

There are many price factors to consider when calculating the cost of double glazed doors and windows. So, it’s best if you ask a professional for a quotation. The tool on this website will put you in touch with competent and professional window installation companies who specialise in double glazing.

Why install double glazing?

Installing double glazing in your home will on average increase its value by up to 10%. Moreover, it can make your house easier to sell. In fact, 80% of home buyers reckon that they always look for double glazing during the initial search.

Insulating your home obviously saves money on heating, and modern doors and windows are one of the best ways to do this when used in conjunction with other insulation methods.

Double glazing also reduces the amount of damp and mould in your home as long as you have good air circulation.

This type of door and window increases your home security as the glass is harder to smash, the frames are stronger and are fitted with more latches.

Other Tasks Associated with Double Glazing

If your existing double glazed windows are a few years old, you might have condensation mist within the glass unit. This is caused by a fault in the seal. However, you don’t need to change the whole window as the cost of replacing misted double glazing units is relatively cheap and can be done by any professional glazing company.

After installing a new window or door you will need to repair the surrounding interior wall using plaster, and the outside wall with cement mortar. This is a simple job for a professional.

If your existing windows are in good condition but single glazed, you can fit secondary double glazing to reduce heat loss and draughts. Not only is this a lot cheaper to buy, but you can also fit it yourself if you enjoy DIY. You can also buy secondary glazing kits from many home improvement centres.

What about Local Authority Regulations and National Standards?

The UK Building Regulations mention double glazed windows and doors with regards to insulation, ventilation and fire escape regulations. Newly installed windows need to be inspected by the local authority or be self certificated by a competent installation company.

In most cases, the only time you need Planning Permission when installing replacement double glazing is when you live in a listed building. Furthermore, there may be additional restrictions if you live in a conservation area, national park or area of outstanding natural beauty. To be safe, always ask for advice from your local authority.

In addition to these regulations, all modern replacement windows and doors must comply with National and Europen Standards.

The best way to achieve compliance with all regulations is to employ a FENSA or CERTASS registered company. They are able to self certify that their own work complies with the Building Regulations. Use the tool provided on this website to request quotations from competent professionals.

Health, Safety and Environmental

Handling glass is always a risky business. Both for personal injury and potential property damage. Always use a registered professional who will know the dangers and how best to work with glass.

Removing existing windows and doors creates a lot of waste. Be sure to hire a waste skip from a registered company and inform them that you intend to put broken glass inside. They usually have specific procedures for transporting glass in order to protect their workforce, and sometimes require it to be segregated from other waste. Check with the skip company first.

Replacing upper windows will always require some type of scaffolding or working platform. Therefore you will have to cover the rental cost of anything the professional needs to keep safe.

When handling glass always use appropriate safety equipment.

Who is competent to install double glazed windows?

Although replacing doors and windows with double glazing may seem easy when done by a professional, it is harder than it looks. Installing double glazing is not something for DIY readers. Not only is it difficult to remove existing windows and doorframes without causing major damage to the surrounding walls, but it is also very hard to install frames so they are vertical, square and without any twist.

As an amateur, you also won’t be able to have the installer issue a FENSA certificate to prove it complies with the Building Regulations.

Therefore, only use experienced and competent professionals to install your replacement double glazing. Ensure the installation company has the appropriate insurance to cover injury, death or property damage before hiring them. Don’t just take their word for it, ask to see the insurance policies.

Use professionals who are members of FENSA, CERTASS (these are able to self-certificate for Building Regulations purposes) or who belong to the Glass and Glazing Federation, The latter organisation also provides training for its members.