The cost of double glazed windows is £290 to more than £1,135 based on the size, material and type of window. Bay and bow windows cost more, because they are an assembly containing several separate windows.
Most windows are priced in a narrower range from £365 to £700.
|Double Glazing Windows Cost & Prices|
|Material||Fitted Cost Range||Casement||Tilt & Turn||Sash||Bay or Bow|
|UPVC||£250 – £1,400||£250 – £550||£280 – £575||£455 – £780||£1,100 – £1,400|
|Aluminium||£310 – £1,675||£310 – £610||£365 – £700||£650 – £900||£1,250 – £1,675|
|Composite||£345 – £1,800||£345 – £650||£380 – £750||£700 – £960||£1,385 – £1,800|
|Wooden||£530 – £2,400||£530 – £880||£735 – £925||£850 – £1,135||£1,700 – £2,400|
Tables below show additional detail on double glazed window prices by material and type. You will also see estimates for common house types – apartments to multi-storey detached homes. If you’re looking for UPVC conservatory prices check out our UPVC conservatory cost guide.
Double Glazed Windows Cost Factors
Material and window type are obvious cost factors. There are a few others to consider:
Window size: The larger the window is, the more it will cost for two reasons. First, there is more material in the window. Secondly, large windows take longer to install and might require a second tradesmen to help. See the cost table for Windows by Size below.
Number of windows: Cost per window drops slightly as the number of windows installed goes up. This is because travel costs, insurance, permitting and other costs for the tradesmen are spread over more windows.
Glazing type: We’re discussing double glaze windows, but if the glass is toughened or coated for energy efficiency, or if the space between panes is filled with a gas like argon, cost will increase. Specialty glass such as tinted or frosted glass might cost more too.
Quality: Timber, uPVC, aluminium and composite windows are all available from quite cheap to top of the line. Cost rises with quality.
Type of wood: Your options for wooden windows are soft or hard timbers. Hard timbers, i.e., hardwood windows, cost more than those made from soft timber. Engineered timbers is another option that we’ve listed separately as composite windows.
Clad wood: Your options for timber windows are unclad and clad. Windows that have exteriors clad with aluminium cost more but are much better protected against the elements.
Finished vs unfinished: Most timber windows are stained and sealed at the factory. If you choose unfinished timber windows and do the work yourself, you’ll save on cost. However, buying unfinished windows and hiring a finisher will cost more total than buying finished windows.
Bespoke windows: The double glazing costs in this guide are for standard-sized windows. If your window openings are odd and require bespoke windows, expect costs to be 1.5 to 2 times higher than these.
Who installs your windows: Installers with CERTASS or FENSA accreditation. Using accredited tradesmen will cost more might will better ensure the job is done properly and you won’t have problems with the windows.
Is Paying More for Timber Windows a Good Idea?
Timber windows offer timeless beauty, but maintenance demands are much higher than for uPVC and aluminium. Are they worth paying the higher cost?
The answer is “yes” if: You intend to live in your home indefinitely, the cost is within your budget and you are willing to properly maintain the windows. Wood, when carefully maintained, can last 100+ years, while windows of other materials are typically replaced in 15-30 years.
The answer is “no” if: You intend to move in less than 10 years or the cost for wooden windows is higher than you wish to pay.
Double Glazed Window Cost by Material and Size
This table shows how size affects double glazed window cost. These are installed costs, so include the cost of material, manufacturing labour and tradesmen labour to install them.
|Material & Size||Casement||Tilt & Turn||Sash|
|600 x 900 cm||£250 – £425||£280 – £440||£455 – £600|
|900 x 1200 cm||£310 – £470||£335 – £475||£490 – £635|
|1200 x 1200 cm||£385 – £550||£460 – £575||£550 – £780|
|600 x 900 cm||£310 – £460||£365 – £490||£650 – £715|
|900 x 1200 cm||£375 – £515||£440 – £545||£700 – £780|
|1200 x 1200 cm||£565 – £610||£600 – £700||£765 – £900|
|600 x 900 cm||£345 – £490||£380 – £520||£700 – £845|
|900 x 1200 cm||£380 – £540||£435 – £565||£775 – £900|
|1200 x 1200 cm||£500 – £650||£525 – £750||£865 – £960|
|600 x 900 cm||£530 – £675||£735 – £860||£850 – £980|
|900 x 1200 cm||£600 – £765||£775 – £885||£935 – £1,040|
|1200 x 1200 cm||£710 – £880||£810 – £925||£1,000 – £1,135|
How Much Do Double Glazing Windows Cost?
Here are average cost ranges for each window material. Use the cost factors listed above to refine your estimate.
|Apartment 4 or 5 Windows||£1,600 – £3,200||£1,850 – £3,600||£2,600 – £4,500|
|Terraced 6-8 windows||£1,850 – £3,900||£2,250 – £4,200||£3,450 – £6,100|
|Semi-detached 8-10 windows||£2,200 – £4,500||£2,500 – £5,150||£4,600 – £7,300|
|Detached 10-12 windows||£2,650 – £5,250||£3,000 – £5,500||£5,900 – £8,600|
The complete package includes windows of differing sizes rather than all small or all large windows. At least one bay or bow window combination window is factored into all the estimates except the apartment.
Double Glazed Window Cost by Brand
This table shows window supply costs. Fitting the windows costs an additional £75 to £200 per window based on its size and the difficulty of the installation.
|Brand & Type||Supply Cost|
|UPVC||£125 – £980|
|Aluminium||£160 – £900|
|Wooden||£400 – £1,550|
|UPVC||£190 – £1,000|
|Aluminium||£235 – £1,150|
|Composite||£280 – £1,300|
|Wooden||£400 – £1,775|
|Aluminium||£315 – £985|
|UPVC||£160 – £380|
|UPVC||£135 – £860|
|Aluminium||£170 – £915|
|Wooden||£345 – £1,225|
|Wooden||£275 – £1,100|
|Aluminium||£200 – £885|
|Wooden||£375 – £1,750|
|Clad Wooden||£450 – £1,900|
|Wooden||£175 – £815|
|UPVC||£105 – £310|
|Wooden||£350 – £930|
|UPVC||£170 – £1,000|
|Aluminium||£225 – £1,075|
|Wooden||£330 – £1,400|
|Clad Wooden||£400 – £1,565|
Not all the brands make the same range of window sizes or types, so costs vary within each material.
Planning Permission for Window Replacement
You do not usually need to apply for planning permission when replacing existing windows and doors, as long as they are similar in appearance to the hold ones being replaced. If they are vastly different from the previous, or the ones within the surrounding area then you need to consult your local planning office before going ahead. There is a comprehensive overview of planning guidelines for replacement windows at the U.K. planning portal.
Is Window Replacement a DIY Job?
Unless you have experience in construction, we recommend hiring professional installation.
Windows must be properly fitted to ensure they are airtight around the frames. When fixed incorrectly, stresses on the frame will cause them to warp and/or crack.
In short, the majority of the cost is in the windows, no labour. It makes sense to invest in professional fitting to get the long-term benefits from the windows.