Double Glazing Costs 2019: Compare Double Glazed Windows Prices

How do you work out the cost of double glazing? It all depends on the style, size and number of windows or doors you have installed - and our easy calculator below will help you work it all out.

The average cost of double glazing is between £400 and £600 per window. So generally, it will cost around £2,000 to install 4 double glazed windows in a flat, and between £4,800 and £7,200 for your standard UK home.

Is it worth it? The Energy Saving Trust found fitting new double glazing can reduce energy bills by up to £110 a year and increase your property's value by up to 10%.

This page will help you crunch the numbers, or if you would just like to get free quotes to compare directly from leading suppliers near you, just hop to our simple quote tool at the top of the page.


In This Guide to the Cost of Double Glazing:

Head straight to a specific section by clicking the links below



Average Cost of Double Glazing

The average cost of double glazing tends to range between £400 and £600 for a single window, according to the Royal Institution of Chartered Surveyors (RICS).

Of course, prices vary depending on the style, size and number of windows you have installed. Sash windows (the ones you slide up and down), for example, often cost twice the price of regular casement windows, and uPVC windows are also cheaper than wooden or metal frames.

Then there are the sizes: the standard window measures 60cm × 90cm and costs between £350 and £500, while larger frames of 90cm × 120cm average around £500 to £700. Below we explain all.

average cost of double glazing

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How Much Is Double Glazing?

Property
Number of Windows
Price
Flat
4
£2,140
House
8
£4,280
House
10
£5,350
House
15
£8,025

The more windows you have installed, the more double glazing costs. For example, if you're installing only 4 windows in a ground floor flat, it'll cost just over £2,000. If you're having 10 or more windows installed in a large two-storey house, however, the cost will be upwards of £5,000.

To find out the cost of double glazing for your home, just fill in this short form and one of the UK's leading suppliers will arrange a home assessment and quote you a price for installation.


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Double Glazed Window Prices Calculator

Our double glazed window prices calculator gives you an estimate of how much it would cost to install new windows in your home. Just select how many you need and in what style.

*Costs are estimated and based on industry averages. They are not an exact indication of how much you’ll be charged by a window fitter


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How Does the Window Style Affect Double Glazing Prices?

The most popular styles of window in the UK are casement, sash, tilt and turn, dual turn and bay. Casement windows tend to be the cheapest option due to the simplicity of their design, while sash and bay windows are often the most expensive.

To find out more about the different window styles, visit our guide to the best double glazing.

Sash Window Double Glazing Cost

sash window double glazing cost

The cost of a sash window starts from £500, and increases to £1,000, depending on their size, the frame material you choose, and the floor you live on.

What is a sash window? Sash windows are also called hung windows, as they have two panels that hang over each other, and slide up or down to open. It’s one of the most popular styles of window in London, and in period homes.

Below is a list of typical uPVC sash windows costs for different window sizes, including installation fees:

Window Size
Price per Sash uPVC Window
50cm x 50cm
£540 to £720
100cm x 100cm
£640 to £820
120cm x 120cm
£750 to £975


How much do sash windows in London cost? The cost of double glazing a period or Victorian house is often slightly higher, since every window can be a different size. With its abundance of such properties in the capital, the average cost of a sash window in London averages between £700 and £800.

How much do sash window repairs cost? Double glazing builds strength into windows, and shouldn’t crack easily under pressure. But if you ever did need to repair the double glazing on your sash window, you can expect to fork out anything between £20 (for minor scratches) to over £500 (for a full replacement, usually after 20 years).

Bay Window Double Glazing Cost

bay window double glazing cost

A bay window costs between £1,000 and £1,700, depending on the materials and double glazing supplier you choose. Seems like a large range? That’s because the range of bay window sizes tends to be greater than average.

What are bay windows? Bay windows are the luxurious ones that arc outwards, beyond your property walls. And with this extra space comes more room for panes of glass, which is why double glazing bay windows can be more pricey than regular designs.

The table below shows you the typical cost of different sized bay windows. Pricing includes installation fees.

Window Size
Price per Bay uPVC Window
240cm x 120cm
£1,000 to £1,100
240cm x 150cm
£1,100 to £1,200
300cm x 120cm
£1,400 to £1,500
300cm x 150cm
£1,500 to £1,600
360cm x 120cm
£1,500 to £1,600
360cm x 150cm
£1,600 to £1,700

Casement Window Double Glazing Cost

casement window double glazing cost

Casement window costs between £250 and £500, depending on the size of windows and number of frames you need.

What are casement windows? A casement window opens thanks to one of more hinges, usually at the side. Many homes have just one or a pair of casement windows within a frame, and they tend to be common in new builds and conservatories in the UK.

The table below gives you an idea of the price of different sized double glazed casement windows, and includes installation costs.

Window Size
Price per Casement uPVC Window
50cm x 50cm
£275 to £360
100cm x 100cm
£325 to £420
120cm x 120cm
£375 to £460


Tilt and Turn Window Double Glazing Cost

tilt and turn window double glazing cost

A tilt and turn window costs between £400 and £700, depending on the size, and frame material you choose.

What are tilt and turn windows? Tilt and turn windows can open from hinges, just like casement windows. Or, if you’d like to keep the cool air out, you can tilt them from the bottom, leaving a smaller gap.

The table below gives you an idea of the price of different sized tilt and turn windows, and includes installation costs.

Window Size
Price per Tilt and Turn uPVC Window
80cm x 80cm
£415 to £590
100cm x 100cm
£490 to £625
120cm x 120cm
£525 to £690


Dual Turn Window Double Glazing Cost

Dual Turn Window Double Glazing Cost

The cost of a dual turn window starts from £400, and increases to £750. They’re similar to tilt turn windows, but the added flexibility makes for a more complex design, which bumps up the costs a tiny bit.

What are dual turn windows? If it’s easy to clean your windows from inside your home, you probably have dual turn windows. With this design, your windows can fully rotate as a nifty alternative to sash windows.

This table shows the price of different sized dual turn windows, including the cost of installation:

Window Size
Price per Dual Turn uPVC Window
80cm x 80cm
£440 to £675
100cm x 100cm
£525 to £670
120cm x 120cm
£550 to £725


Roof Window Double Glazing Cost

With their smaller glass panes, double glazing roof windows will set you back much less than other styles.

The full fitting of roof windows costs between £570 and £1,500 per window, including installation. These prices will depend on the shape of the windows, and whether you want them to open or not, with more complex specs upping the price.

Fixed roof windows cost between £570 and £1,000, and opening roof windows go right up to £1,500, with curved glass at the upper end - all based on Velux’s current prices.

What are roof windows? Also known as skylight or Velux windows, roof windows do exactly as they say on the tin. They’re the windows you stick into rooves to admire the sky, or try to squeeze out extra doses of vitamin D.



Double Glazed Door Cost

upvc bifold doors cost

The cost of double glazing your doors can vary greatly. Perhaps you’re just after two small panes for your front door, or maybe you have full-glass patio doors in mind.

Front doors start at around £300, and sliding glass doors can set you back over £2,000 typically. The more glass you need, the more you can expect for your double glazing quotes.

uPVC bifold doors cost between £1,950 and £3,900, on average. Plus, you can expect to pay £250 for the installation itself, which usually lasts a full day.

What are uPVC doors? You may also know bifold doors as patio doors or sliding glass doors. They’re the ones with huge panes of glass that can slide or fold like a concertina to open.


Get a Free Window Quote for Your Property


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How Does the Window Frame Material Affect Double Glazing Prices?

There are three main types of window frame material available in the UK: uPVC, aluminium, and wooden (or timber effect). uPVC is the cheapest window frame material, while wooden and aluminium frames normally cost around 30% to 50% more.

You can also have window frames made from vinyl or composite materials, but they’re less common, as many people prefer the authentic finish of traditional frames.

Do I need a new frame? Even if you already like your existing window frames, you will need new ones for double glazing, so there is an airtight seal between the glass and frame. Any gaps will pull debris in between the panes of glass that you won’t be able to clean, not to mention reducing their efficiency.

The table below shows you the average price of uPVC, wooden and aluminium windows in different sized properties. These double glazing prices include installation fees:

Property Type
Number of Windows
uPVC
Aluminium
Wooden
Flat
4
£2,140
£2,288
£3,508
House
8
£4,505
£4,856
£7,248
House
12
£6,762
£7,284
£10,872
House
16
£9,016
£9,712
£14,496


uPVC Double Glazing Cost

The table below shows the average price of different sized uPVC windows. These prices are based on quotes obtained from some of the UK's leading installers, and covers the cost of the window as well as installation:

Size of Window
Location of Window
Price per uPVC Window
60cm x 90cm
Ground floor
£500 to £570
60cm x 90cm
Second floor
£560 to £625
90cm x 120cm
Ground floor
£775 to £840
90cm x 120cm
Second floor
£840 to £900
120cm x 120cm
Ground floor
£835 to £895
120cm x 120cm
Second floor
£905 to £960

We visited a homeowner receiving quotes for 8 large uPVC windows from Safestyle. Safestyle is one of the most well-known national window installers and offers some of the cheapest double glazing prices. Here's the quote given to the homeowner:

Installer
Frame Material
Style
Number of Windows
Energy Efficiency
Quoted Cash Price
Safestyle
uPVC
Cottage
8
A++
£5,475

Some companies make uPVC 'wood effect' windows which are more expensive than basic white uPVC windows, but cheaper than timber frames. We visited a homeowner receiving quotes for 8 large uPVC wood effect windows from 2 of the biggest window installers in the UK: Anglian and Zenith. Below are details of the quotes given to the homeowner:

Installer
Frame Material
Style
Number of Windows
Energy Efficiency
Quoted Cash Price
Zenith
Woodgrain
Georgian
8
A
£17,286
Anglian
Woodgrain
Cottage
8
A++
£11,503

Learn more about uPVC windows


Aluminium Double Glazing Cost

The table below shows the average price of different sized aluminium windows based on quotes we received from installers in the UK. Pricing covers the cost of the window as well as installation:

Size of Window
Location of Window
Price per Aluminium Window
60cm x 90cm
Ground floor
£540 to £605
60cm x 90cm
Second floor
£605 to £680
90cm x 120cm
Ground floor
£655 to £735
90cm x 120cm
Second floor
£715 to £800
120cm x 120cm
Ground floor
£770 to £875
120cm x 120cm
Second floor
£845 to £955

Learn more about aluminium windows


Wooden Double Glazing Cost

The average price of different sized wooden windows can be seen in the table below. These prices are based on quotes from some of the UK's leading installers. Pricing covers the cost of the window as well as installation:

Size of Window
Location of Window
Price per Wooden Window
60cm x 90cm
Ground floor
£845 to £910
60cm x 90cm
Second floor
£900 to £970
90cm x 120cm
Ground floor
£1,245 to £1,300
90cm x 120cm
Second floor
£1,325 to £1,380
120cm x 120cm
Ground floor
£1,365 to £1,405
120cm x 120cm
Second floor
£1,425 to £1,495

Learn more about wooden windows


Get a Double Glazing Quote for Your Home


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How Much Can You Save?

Many factors affect the amount you can save by installing double glazed windows. Your average annual energy usage, the energy efficiency of your new windows and the size of your property are just some of the factors to consider when estimating your financial savings.

Studies have shown that households that transition from single glazing to double glazing with an energy efficiency of A+ can save up to £110 per year on their energy bills. These are calculated by the Energy Saving Trust and are based on gas-heated houses:

Energy Efficiency
Detached
Semi-Detached
Terrace
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

Saving money by reducing your energy bills is only one of the many benefits that double glazing can bring; it adds value to your home and can cancel out unwanted noise from outside. The extra layer of glass also improves your home's security, should a burglar attempt to break into your property.

double glazing cost savings Based on a survey we conducted in May 2018 of 775 homeowners who'd had new double glazed windows installed in the last 2 years.

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Double Glazing Cost vs Triple Glazing Cost

Triple glazing is made up of 3 layers of glass instead of just 2, so as you might expect, it costs more than double glazing. For example, a triple glazed uPVC window costs around £100 to £200 more than a double glazed uPVC window. The table below shows you the average price of triple glazing compared to double glazing, and gives you an idea of the extra cost incurred by the additional pane of glass.

Window Frame Material
Double Glazing Cost
Triple Glazing Cost
White uPVC
£400 to £600
£500 to £700
Wood Effect uPVC
£500 to £700
£600 to £800

Because triple glazing has an extra pane of glass, it enhances all the benefits that double glazing offers, including improved thermal performance. The energy efficiency of a window is represented by the U-value, which measures how well a window can retain heat. Triple glazed windows have a slightly better U-value than double glazed windows, meaning triple glazing will keep your home that little bit warmer. You'll therefore be able to save a bit more on your energy bills with triple glazing than with double glazing.

The table below shows how much you could save each year by replacing single glazing with double glazing and triple glazing, in a detached and semi-detached house:

Glazing Type
Energy Efficiency
Detached
Semi-Detached
Double
A+
£110
£80
Triple
A+
£175
£125
Double
A
£105
£75
Triple
A
£160
£110

Good to know: although triple glazed windows can save you more money on your energy bills, the payback period for triple glazing is likely to be similar to that of double glazing due to its higher upfront cost.


How Much Would Double Glazing Cost for Your Home?


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Double Glazing Cost vs Secondary Glazing Glazing Cost

Secondary glazing is a popular option for those on a budget, and can cost up to half the price of double glazing, depending on whether you'd like sash or the slightly cheaper horizontal sliding windows.

On top of window style, the glass material will determine the final price. The cheapest type of secondary glazing is draft reducing glass, which costs between £685 and £870. Noise reduction secondary glazing needs to be tougher, and costs between £895 and £1,057 per pane.

What is secondary glazing? This type of installation is different from double glazing because it adds an additional pane of glass in front of your existing windows, so you don't need to replace them.

Type of glazing
Cost of noise reduction secondary glazing
Cost of draft reduction secondary glazing
Sash windows
£1057 + VAT
£870 + VAT
Horizontal sliding windows
£894 + VAT
£685 + VAT



Does Double Glazing Increase Property Value?

Fitting new double glazed windows in your home can increase its market value by up to 10%. Many estate agents agree that double glazing can make your home more 'sellable', with a survey by GoCompare finding that 80% of home buyers believe double glazing is a 'must have feature' when purchasing a property.

In an interview with thisismoney.co.uk, a representative from Henry Adams estate agency in Sussex said that the owners of a terrace cottage were able to sell their home for £40,000 more than the original asking price, simply by replacing single glazing with new double glazed wooden windows at a cost of £18,000.

Estate agents do warn against installing the wrong type of double glazing for your home, however, as this can actually decrease its asking price. For example, buyers of period homes want traditional wooden window frames, so fitting uPVC double glazed windows will decrease a property's desirability, causing its price to fall.


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What Should Your Quote Include?

Your quote should include a description of the windows you're having installed and where, a complete breakdown of the costs involved, and how long the installation will take to carry out. This information should be provided to you on paper, unless you agree to receiving your quote via another medium, such as an email.

Costs that should be in included in your quote are:

• A full technical survey of your property

• The number, size and style of the windows

• Full installation of the windows

• Additional equipment for installation (e.g. scaffolding if needed)

• Removal and disposal of your old windows

If you're unsure about any costs, ask your installer to explain them to you. A trusted installer should be happy to do this. You should avoid any installer who demands a large deposit upfront, pressures you to sign a contract on the spot, or doesn't provide a landline telephone number. These are warning signs that they do not work for a reputable window installation company.

We recommend that you compare like-for-like quotes from at least 3 installers. It's also worth asking to see examples of their work within your local area to get a sense of the quality of their work and whether they're a company you want to use to install your double glazing.

To get an estimate of how much it would cost to install new windows in your home, take a look at our free and easy-to-use window cost calculator.


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7 Tips to Get the Best Double Glazing Prices

Here are our top 7 tips to get a great price for your new windows:

1. Compare quotes from at least 3 window companies. We recommend requesting quotes from leading installers such as Everest, Anglian, Safestyle, and Zenith.

2. Ensure all the installers you get quotes from are registered with FENSA or the Glass and Glazing Federation (GGF). These Competent Person Schemes (CPS) work with window companies to ensure that they comply with the UK Government’s building regulations. Certification from these bodies ensures you avoid any rogue traders - choosing an illegitimate company can be a costly mistake.

3. Before you get a quote from an installation company, have in mind exactly what style of window you want. Changing your windows again in the future because you no longer like the design can be expensive.

4. Do not fall into the trap of hard sales pitches. Any reputable installation company should offer you a quote and then give you time to consider your options.

5. Try not to be pressured into ‘on the day’ quotes. While you might be offered a better price for your windows if you sign a contract immediately, you'll often have to pay a very large upfront deposit. These companies do not have your best interests at heart and you will be much better off dealing with a more reliable installer.

6. Buy at quiet times of the year. December is usually the quietest time of the year for most installers. So buying your double glazed windows in this month will usually mean that you'll get a good deal as they'll want to make a sale.

7. Negotiate with the salespeople. Don't be afraid to negotiate. Salespeople often push their luck and will quote you an inflated price hoping that you'll take the bait. Barter with them and they'll often drop their quote by several hundred (or even thousand) pounds.


Windows Case Study: Get Multiple Quotes & Don’t Rush To Sign

Ash McEvoy, London

Ash had 3 uPVC double glazed windows installed in his London flat in 2017. His advice is to get multiple quotes before committing to a firm - and don’t be too hasty when the costings come through.

“I decided to get quotes from 3 national installers because I believed the prices would be more competitive. Surprisingly, there were huge differences in price from one company to another and this made me think that there was a deal to be had.

“I didn’t respond to my preferred installer’s quote for a week and then they got in touch to offer a much cheaper price, of which I happily accepted.

“I’d say don’t rush to sign on the dotted line, and try to brush up on the different window types and features before meeting with companies; they can bombard you with confusing or misleading jargon that may result in buying a lower quality product.”



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Cheap Double Glazing

double glazing prices

While tempting, it’s important to be cautious of cheap double glazing. You can use the prices in this article as a benchmark - anything too off kilter, and you’re probably paying too much or too little!

We don't recommend buying cheap double glazing. Low prices are often a sign of poor quality meaning you won’t reap the benefits that double glazed windows have to offer. Cutting corners on better insulation and improved security could cost you money in the long-term.

Here are the main risks of cheap double glazing to look out for:
  1. Scratches on windows - Less reputable companies may have less infrastructure to protect your windows in storage and transit. And if there are any damages, it may take a while to find a replacement that fits.
  2. Poor fit - The glass needs to fit the frame properly, otherwise it’ll get drafty.
  3. Seal fails - This is the big one. The vacuum between the panes of glass will pull in debris or condensation if the seal ever lets up. It’s called double glazing desiccant, and you won’t be able to remove it yourself.

But What If You're on a Budget?

We get it. You want to save on your double glazing without missing out on quality. If you're on a budget, there are ways to bag a bargain that'll stand the test of time.

1. Get windows with a lower energy efficiency. You don’t need to buy windows with an Energy Performance Certificate (EPC) rating of A to A++ . Windows with a slightly lower EPC rating of B or C are still good quality and will allow you to enjoy the benefits of double glazing at a lower price.

2. Look out for flash sales or limited-time offers. Some companies have flash sales on their windows throughout the year. It can be difficult to know when they come and go, however, so by signing up to a company’s newsletter you can receive notifications of any deals that are currently on offer.

3. Negotiate with salespeople. As we’ve already said, double glazing salespeople have a pretty lousy reputation, but knowing their tactics means that you can stay one step ahead and secure a good price on your windows. Sales consultants will often try their luck and quote you an inflated price for your new windows - but don’t get sucked in, as they’ll probably be ripping you off. Instead be confident and haggle with them, and you’ll be able to cut hundreds (or even thousands) of pounds from the total cost.

4. Replace all of your windows in one go. Whether you’re switching from single glazing or are simply upgrading your old double glazing, you can save a lot of money by replacing all of your home’s windows rather than just a few. Most companies will offer you a generous discount if you install 10 or more windows at once, since a large job is more cost-efficient for them (rather than lots of smaller jobs).

5. Consider secondary glazing. If you have single glazing, you can simply add an extra pane of glass to your existing windows rather than installing completely new double glazed windows. Because it is less labour-intensive, secondary glazing is typically cheaper than double glazing and takes a lot less time to install.

6. Retrofit your new double glazing into your old frames. If your existing window frames are in good condition, then an installer might be able to retrofit new double glazing into your current frames. This will save you money as you’ll only need to pay for the panes of glass rather than the whole window.



New Double Glazing FAQs

How long does double glazing last?

The average life expectancy of double glazing is around 20 years. That’s because the (argon) gas between the panes gradually leaks out, and the vacuum effect weakens in this time.

Of course, you can still keep the windows as they are. They’ll still keep more noise out, but the double glazing won’t be so effective at keeping your heat in.

To get more years for your buck, it's worth hiring a well-rated double glazing professional. Cheaper materials materials may only last closer to 10 or 15 years, so it's worth getting your money’s worth.

Are double glazed windows worth it?

Of course, it depends on your personal situation. But if you can afford them, double glazed windows are proven to help you save on energy bills, whilst keeping your home warmer and safer.
  • Are double glazed windows expensive? Double glazed windows cost around 20% to 35% more than single glazed windows, though you can cut your energy bills too.
  • Which are the 5 best double glazing companies in the UK?
  • Are there any government grants for double glazing?

  • Get a Double Glazing Quote from a Trusted Installer in Your Area


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    What If You Go Direct to a Window Manufacturer?

    It's possible to buy your windows directly from a window manufacturer. Double glazing prices will often be cheaper as installation is not included.

    However unless you have experience in fitting windows yourself, you'll still have to pay for installation. Going direct to a window manufacturer without your own window fitting expertise is not recommended as the correct installation is essential to ensure your windows are fitted properly.

    To give you an idea of how much you would pay for windows bought directly from a manufacturer, we've outlined the costs in the table below. These prices are for A-rated uPVC double glazing bought from Direct Window Company, a leading UK window manufacturer:

    Size
    Price per Window
    60cm x 120cm
    £199
    150cm x 120cm
    £299
    180cm x 120cm
    £329

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    Double Glazed Window Repair Cost

    Well-installed and quality double glazed windows typically last for about 20 to 30 years before they need replacing. Within this time, your windows can become tired and worn meaning that they might be prone to some breakages. In most cases you won’t need to completely replace your windows; there are specialist repair companies who can quite easily fix them at a fraction of the cost.

    Some of the most common problems with double glazed windows include broken locks, hinges and handles, or the build-up of condensation between the panes of glass. You should expect to pay between £25 and £100 for most repairs.

    The table below gives you an idea of how much double glazed window repairs cost:

    Repair
    Cost
    Handle repair or replacement
    £25
    Lock repair or replacement
    £50
    Hinge repair or replacement
    £60
    Glass replacement
    £100

    Always check your warranty. Nowadays, most windows come with a 5-year glass warranty and a 10-year frame and sealant warranty (although this can vary). If damage occurs to any of these parts during their warranty period, likelihood is that you won’t have to pay a penny for them to be repaired.


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    How Do You Get a Free Double Glazing Quote?

    Want a tailored quote? To find out the real cost of your double glazing or window repair, it’s worth getting some free quotes under your belt, all tailored to your specs.

    Every day, Eco Experts helps readers find a supplier they can trust at a decent price by making it easy to find and compare double glazing costs.

    To find out the prices at the well-reviewed double glazing companies near you, just tap your area in the map below or use our simple quote tool here.

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