Double glazing can save you money, improve the value of your home, and reduce hot and cold spots in your house.
But, if you’re investing in new windows, you need to know that you’re making the best choice, getting the best for your money, and buying something that will last.
- Double glazing costs an average of £300-£400 per window, if you choose uPVC frames
- Different frames, glass types, and other options dramatically affect the cost
- Replacing old windows in a detached home could save you £175 or more per year on electric bills and increase the value of your home.
- With over 3,000 double glazing installers in the UK, you can benefit from competitive quotes to reduce prices and get the best deal. Click here to compare prices.
If you’re considering installing new windows, you have to know how much they will cost, what your options are, and how to make the best decision for your home. We’ve put together a complete guide to double glazing windows in the UK to help you, so you can make the right investment.
In this guide you will find:
How much does double glazing cost?
What does double glazing efficiency mean for you?
What types of double glazed windows are there?
Pros and cons of double glazing
Who are the best double glazing installers?
How important are double glazing warranties?
Double Glazing Costs
Double glazing costs are probably your most pressing concern, because you likely have a budget or an idea of what you want to spend. Double glazing windows are priced based on material, efficiency, size, type, and style. However, the average cost of a standard window, or a casement window with a uPVC frame is £300-400 per window. This is the most commonly installed window in the UK.
There are several factors that will affect how much you are likely to pay for your windows. For example, the following chart includes the average price ranges for a B to C rated casement window in a standard size like 60 x 90 cm.
| Material | Cost |
| UPVC | £250-570 |
| Aluminium | £500-605 |
| Composite | £575-625 |
| Wood | £845 – £910 |
These prices are averaged for the median cost of windows of this type, and the range may be more or less expensive depending on your home, the condition of your existing windows, the installer, and the size of the windows.
What Affects Costs
While you can easily get an online quote to see an estimate of total costs of installation, no online quote will ever be 100% accurate. This is because a large percentage of double glazing costs are fitting costs, which are factored based on your home, windows, and other specific points.
Home – The condition of your home, stories, condition of existing frames, modifications needed, etc., will all affect costs. The more difficult it is to have your replacement windows fitted, the higher the price will be.
Location – Most installers will charge to come out to your location, so choosing a nearby installer will likely reduce rates.
Frame – As covered above, frames are priced differently.
Glazing – Standard glazing is relatively affordable, but you can choose upgrades such as argon gas, Low E coatings, or other additions to improve energy efficiency.
Installer – Some installers charge more than others, either because they offer higher quality windows or because they are a well known brand.
In most cases, best practice is to compare your options to determine what is available so you can choose the best quality windows for the best price.
How much can you save with an investment of this size?
Double Glazing Efficiency
While cost is an important factor, you are likely planning to upgrade your windows to save money. How efficient are glazed windows? That depends on the window, the type of glass, whether you have air or inert gas cushions, and other factors such as frames and sealing. However, your most important concern is probably whether you can save money.
Double Glazing Savings
Double glazing reduces your energy bills by slowing heat loss, so you spend less money heating and cooling your home. While the amount you save is low, it adds up a great deal over time, and can help you to reduce your total yearly bills. For example, if you’re replacing old windows with double glazing, you can expect to reduce total heat loss by about 18%, reducing your heating bills a comparable amount.
This translates to direct savings for you. The Energy Savings Trust calculates that if you were to replace single pane windows in a home with double glazing, you could save the following per year:
| Window Energy Rating | Detached | Semi detached | Mid terrace | Bungalow | Flat |
| A rated | £130 – £175 | £90 – £120 | £80 – £105 | £60 – £80 | £50 – £65 |
| B rated | £120 – £160 | £80 – £110 | £70 – £95 | £50 – £70 | £40 – £60 |
| C rated | £120 – £150 | £80 – £105 | £70 – £90 | £50 – £65 | £45 – £55 |
If you have a larger home with 4-5 bedrooms, you will save more. If you currently have older double glazing with a lower energy rating, you will save less.
WER Rating
WER Rating or the Window Energy Rating is a calculation that combines all the energy efficiency standards applicable to your windows to create a single comprehensive performance measurement. This allows you to see how efficient your windows are at a glance. WER rating combines U value (thermal insulation), G-value (solar gain), R-value, and other factors to calculate exactly how efficient windows are. British law mandates that any new windows should be C rated or higher, while old windows can be E or lower.
The higher the WER rating, the more energy efficient the windows.
Coatings
Glazing can feature coatings to add additional properties to the glass, such as UV resistance, emissivity resistance, or higher efficiency. Low E or low emissivity is one of the most common coatings. A coating will improve the overall energy efficiency of your home.
Making Your Money Back
While it may seem logical to simply buy the most energy efficient windows you can afford, this isn’t always the best choice. If your primary goal is to reduce your total energy usage and carbon footprint as much as possible, but budget isn’t a large concern, buying A++ windows or triple glazing is a great option. However, you will not likely earn your money back, because the additional energy savings are not enough to account for the higher cost of installation. For this reason, you should carefully consider the total cost of installation, calculate your savings over the lifetime of the windows, and determine if you can earn your money back before making an investment.
| Material | C Rated Cost | A Rated Cost |
| UPVC | £250-570 | £325+ |
| Aluminium | £500-605 | £675+ |
| Composite | £575-625 | £747+ |
| Wood | £845 – £910 | £1098 + |
The average double glazing installation in the UK costs £3,000-£5,500, for a detached home with 8-15 windows. However, if you choose windows with a higher WER, you may pay more.
Now that you know how much double glazing is likely to cost to install and how much you can earn back, you can consider your options, decide what you want, and make an informed decision for your house.
Types of Double Glazing Windows
Double glazing windows are available with different styles, frames, and glass, all of which affect the price. Some installers claim to have over 750 different window options, which allows you to pick almost any window to suit your home.
Frames
Most of us think of frames in terms of style and aesthetic, but there are other considerations. For example, as you already learned, some frames are more expensive than others.
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Wood/Timber – Wood and timber windows are the most expensive, with prices typically starting out at twice or even triple that of regular uPVC frames. Wood frames are typically treated to prevent rot and mould, but require a high level of regular care to maintain. However, these frames add value to your home, are most appropriate for heritage homes, and typically last more than 25 years with proper care. |
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UPVC – uPVC or unplasticized Polyvinyl Chloride frames are affordable, energy efficient, and low maintenance. While the cheapest double glazing option, with proper care, uPVC windows typically last between 10 and 20 years depending on quality, installation, size and brand. These windows add the least value to your home, but do allow you to upgrade to double glazing with a minimum fitting cost. To ensure they last long enough to pay off, get a quality warranty from a reputable installer. |
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Composite – Composite windows are made of wood chips, like composite doors, which are compressed to offer strength, durability, and low thermal transference. Composite windows are typically priced between the cost of uPVC and wood, but add a similar value to your home as uPVC. Unlike uPVC, composite requires more care, and is susceptible to rot or mould without cleaning. |
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Aluminium – Aluminium windows offer durability and strength, with a potential long lifespan, but do have trade-offs. Aluminium frames are the second most expensive option, but offer the lowest energy efficiency. However, they are easy to care for, durable, and will improve energy efficiency when installed with thermal breaks. |
Choosing the Best Frame for Your Home
Most British homeowners opt for uPVC windows because they are affordable and energy efficient. However, while a popular choice, they may not be right for you. If you plan to sell your home, want to add to the value of your home, or have traditional windows, you might prefer another option such as wood or aluminium.
In most cases, uPVC windows are a great base option that will last an average of 15 years, and will pay themselves off. If you choose a more expensive frame, your windows may not increase savings enough to reach parity.
Glazing
Glazing can vary a great deal depending on the manufacturer, style, and other features.
Glass Types – In most cases, glass types refer to coatings, the manufacturing method, or the thickness of the glass. Common options include Low E, Reflective, toughened glass, laminated glass, or tinted glass. Each of these finish options is common with double glazing.
Insulating Cushion – Double glazing stops hot and cold air by providing a barrier between your home and the outside. This is most commonly achieved by sandwiching a layer of air or gas between two panes of glass. Standard double glazing features air between the panes. However, you can improve efficiency by choosing an inert gas filling such as argon or xenon gas. While gas-filled windows do cost more, they can make a big difference to energy savings. For example, a standard double glazing window will lose about 17.5% of total heat while an argon filled window will lose about 12.25%.
Cosmetic Options – Many double-glazing installers offer cosmetic features such as leaded glass, stained glass, or other types of decorative glass. You typically pay a premium for these designs, but they do not offer any other benefits.
Frame Styles
While frame materials affect costs, you also need to consider frame styles. Common frame styles include sash, casement, tilt & turn, French, and turn dial. Casement windows are usually the most affordable, while sash frames are more expensive.
Sash – Sash windows feature interlocking frames that open by sliding up, so that the frames overlap. These frames are one of the most expensive options, but offer a very high level of security. While more expensive, some insurance companies offer reduced rates for more secure windows. You can check with yours to see if there is a trade-off for installing sash windows before deciding.
Casement – Casement windows are standard outward turning windows with simple interlocking mechanisms. These windows are the most affordable, but offer high energy efficiency and can feature multi-point locks for security. French windows are simply paired casement windows opening opposite each other.
Tilt & Turn – Tilt and turn windows can open via a standard hinge or can open to tilt out or in. This allows you to open windows slightly to increase airflow without letting in rain or risking the windows to strong winds. While more convenient, these windows offer similar durability and security to casement windows but cost more.
| Type of Window | Average Cost |
| Casement | £250-570 |
| Sash | £500-1,050 |
| Tilt & Turn | £400-675 |
In most cases, your frame options are a personal choice, which you can choose based on aesthetic and personal preference.
Pros & Cons of Double Glazing
Should you really install double glazing? Double glazing offers a great deal of benefits but surprisingly few cons.
Pros of Double Glazing
- Adds to home value
- Reduces heating bills an average of 18%
- Last 10-25 years or longer
- Long warranties
- Reduced carbon footprint
- Typically low maintenance
Cons of Double Glazing
- Sealed glazing units are difficult to repair
- With average costs of installation at £3,000, double glazing is expensive to install
What About Double Glazing Grants or Free Windows?
Unfortunately, there are very few opportunities to qualify for double glazing grants or free windows for the average UK homeowner. While the Green Deal offered assistance with double glazing, this initiative has largely been shut down, and you can no longer get assistance from the government when upgrading windows.
However, if you are in need, are over 60, or are receiving benefits or pension credit you may qualify for several double-glazing grants. These include:
- Home Repair Assistance Grant
- Care & Repair
- Housing Aid for Older People Scheme
Unfortunately, there are no real grants or free double glazing initiatives for regular homeowners or renters.
Secondary Glazing as a Cost Effective Alternative
If your goal is to improve the energy efficiency of your home without a large investment, secondary glazing may be a solution. Secondary glazing involves installing a secondary pane of glass behind your existing glass, giving you some of the benefits of double glazing. However, this method may not be ideal if your frames are old, not compatible with secondary glazing, or your existing windows are improperly sealed.
Best Double Glazing Installers
The top installers in the UK are Anglian, Everest, Safestyle, Weatherseal, and Zenith.
| Features | Zenith | Everest | Anglian | Safestyle | Weatherseal |
| Guarantee | 10-Year | 10-Year-Lifetime | 20-year | 10-Year | 10-Year |
| Cost | Mid-Low | Mid-High | Low (Price Match guarantee) | Lowest Price Guarantee | Mid-Low |
| Trust Pilot Rating | 7.2 | 7.8 | 7.5 | 8.9 | 6.2 |
| Products | uPVC | Wood, Aluminium, uPVC, | Wood, Aluminium, uPVC | uPVC, Wood | uPVC |
| Frames | 5 | 4 | 5 | 3 | 3 |
Local Installers vs. Big Name Brands
In most cases, you can get slightly lower prices by going to local installers. However, there is a drawback. Most local installers are unable to offer insurance backed guarantees, which means that if they go out of business, your warranty is void. Large companies can offer better customer service, insurance, and faster installation times as well, which may be worth the additional cost.
Warranties & Guarantees
Most double-glazing windows feature a long warranty, but the extent and coverage of this guarantee will vary depending on the installer. In most cases, you can expect an industry standard 10-year insurance backed guarantee. Some installers like Anglian offer a longer warranty (20 years), but you will see this reflected in the cost of the windows. It is important to check for a workmanship guarantee as well as a product warranty to ensure that your fitting and installation
Saving on Double Glazing
Saving money on double glazing ensures that you can earn your money back and possibly make a profit as well. However, it’s important not to cut costs by choosing inferior materials or windows. Instead, you can save money by doing your research, deciding what you want, comparing quotes to get the best deal, and going into sales meetings informed enough to make a good decision.
If you’re ready to see what a custom quote for your home might like look like, use our free quote comparison service to find the top quotes from local installers. We’ll help you to get the best deal by requesting competitive quotes to get the maximum discount, so you can save as much as 37.5% on your double glazing. Or, if you’re not sure if double glazing is right for you, use our website resources to research your options, find solutions that work for you, and learn enough to make an informed decision.
