Double Glazing Cost UK | Free Local Fitting Quote

Double glazing cost for windows typically runs around £400 to £1,250 per window supplied and fitted in the UK, depending on frame material and style. A full replacement for a typical 3-bedroom home usually falls between £4,000 and £15,000. Frame choice, window style, access, and where you live all move that figure, and this guide breaks down exactly how.

If you’ve searched for this because you’re trying to work out whether a quote is fair, you’re asking the right question at the right stage. Most people request three quotes before they’ve fully understood what’s driving the price differences between them, which makes comparing them harder than it should be.

Your kitchen windows might come in near the bottom of that range. A bay window on a Victorian terrace almost certainly won’t. The rest of this guide walks through why, using real UK pricing patterns rather than a single flat number.

How Much Is Double Glazing Cost? Quick Answer

For most homes, double glazing cost sits between £400 and £1,250 per window, or £4,000 to £15,000 for a full 3-bed house, depending on material, style, and access. uPVC casement windows sit at the lower end; bay windows and premium finishes push toward the top.

Double Glazing Cost Per Window

Here’s the part most first-time buyers get wrong: they assume “per window” pricing scales in a straight line. It doesn’t. A single replacement window often costs more per unit than the same window bought as part of a whole-house order, because delivery, scaffolding, and installer time get spread across fewer units.

Cost of Double Glazed Windows by Frame Material

uPVC Double Glazed Windows Cost

uPVC remains the most common choice for good reason; it’s the most cost-effective of the main frame materials, needs minimal upkeep, and doesn’t rot or warp over time. Expect roughly £400 to £850 per window, supplied and fitted.

Aluminium Double Glazed Windows Cost

Aluminium frames run slimmer, which suits contemporary properties and lets in more light per window. That sleekness costs more: typically £650 to £1,250 per window, partly due to the thermal-break technology required to meet current performance standards.

Composite Double Glazed Windows Cost

Composite frames combine a low-maintenance exterior with added structural performance, and typically sit toward the upper end of the pricing scale, often £900 and above per window, depending on specification.

Double Glazed Windows Cost by Style

Casement Window Cost

Casement windows are the baseline against which most other styles are priced, generally running £400–£750 per window thanks to a simple, well-established opening mechanism.

Sash Window Cost

Sliding sash windows cost more, typically £800–£1,500, because of the balance mechanism and the precision needed for period-accurate detailing.

Tilt and Turn Window Cost

Tilt and turn windows sit in the £500–£900 range, with the dual-opening hardware (tilt for ventilation, turn for full opening and easy cleaning) accounting for the premium over standard casement.

Bay and Bow Window Cost

Bay and bow windows are the priciest style, often £1,500–£3,500+ per bay, since multiple panels and structural support are usually involved rather than a single frame.

A quick honesty check here: flush sash windows are sometimes assumed to simply cost double a standard casement. That’s not quite right; the premium reflects the manufacturing precision needed to get the sash sitting flush with the frame, not an arbitrary markup, and the gap narrows considerably on larger orders.

Double Glazing Cost by House Size

Double Glazing Cost for a 2-Bed House

With 5–7 windows typically involved, total cost usually lands between £2,500 and £7,000, depending on style and material.

Double Glazing Cost for a 3-Bed House

Most 3-bed semis need 8–12 windows, bringing the realistic range to £4,000–£15,000. A straightforward casement job for a new-build estate house sits at one end, and a period property needing bay windows sits at the other.

Double Glazing Cost for a 4-Bed House

Larger detached homes, often 12–18 windows plus bay or feature windows, tend to fall between £8,000 and £22,000.

What Affects the Cost of Double Glazed Windows?

Window Size and Glass Specification

Larger openings need more glass and frame material, and non-standard sizes (common in older properties) can’t always use off-the-shelf components, which adds manufacturing time. Low-E coatings, argon gas fill, and warm-edge spacer bars all improve thermal performance, and all add cost. A window rated toward the A++ end of the Window Energy Rating (WER) scale will typically cost more than a C-rated equivalent.

Colour, Finish and Hardware

Woodgrain foils and non-white colours on uPVC frames usually add 10–20% over standard white. Upgraded hardware, multi-point locking, security handles, add a smaller but real amount per window.

Installation Access and Complexity

This is where quotes often start to diverge. Ground-floor, easy-access installs are straightforward. Upper-floor windows, or properties without driveway access for a delivery vehicle, may need scaffolding, which adds directly to labour cost.

Regional Price Differences

London and the South East generally sit above the national average, partly reflecting labour costs and partly local demand.

Installation and Labour Costs

A genuine supply-and-fit quote should include removal of old frames, fitting, sealing, basic making good around the reveal, and disposal of waste. If a quote looks unusually low, check what’s actually included before assuming it’s the better deal.

Supply-Only vs. Fully Fitted Pricing

Supply-only pricing (you arrange your own fitter) is cheaper upfront but shifts risk onto you if something doesn’t fit correctly or the installer isn’t Building-Regulations compliant. Most homeowners are better served by supply-and-fit through a single accountable installer.

Scaffolding, Disposal and Making Good

For upper-floor work, scaffolding hire is a genuine additional cost, often overlooked in early ballpark figures. Ask specifically whether scaffolding, skip hire, and full disposal are included before comparing two quotes on price alone.

How Much Is Double Glazing Cost Compared to Triple or Secondary Glazing?

Double Glazing vs Triple Glazing Cost

Triple glazing costs more upfront and delivers real but often marginal extra insulation over double glazing in typical UK weather; the payback period can be long. Based on Flush Sash UPVC’s experience fitting windows across Buckinghamshire and the Home Counties, the properties where triple glazing genuinely earns its cost tend to sit on busy roads or in exposed rural spots, not the average suburban semi.

Double Glazing vs Secondary Glazing Cost

Secondary glazing, a retrofit second pane fitted inside an existing window, is considerably cheaper than a full double glazing replacement and is often the only realistic option for listed buildings where the original frames must stay in place.

Is the Cost of Double Glazed Windows Worth It?

Energy Bill Savings

Double glazing reduces heat loss compared with single glazing, which can lower heating costs, though the exact saving depends heavily on your existing insulation, boiler efficiency, and how the home is heated day to day. Treat any specific £-per-year figure with caution; it’s a range, not a promise.

Impact on Property Value

Well-fitted double glazing is generally seen as a positive by buyers and valuers, particularly where old single glazing or failed seals are visibly outdated. That said, no reputable installer can honestly guarantee a specific uplift in resale value; anyone who does is worth questioning.

Noise Reduction and Comfort

This is the benefit homeowners on busier roads notice fastest, often more than the energy savings. Acoustic glazing specifications go further than standard double glazing here, if noise is your main driver rather than heat loss alone.

Signs You Need to Budget for Double Glazing Cost

• Condensation forming between the panes (a sign the sealed unit has failed)
• Draughts you can feel even with windows closed
• Frames that no longer open, close, or lock properly
• Visible frame warping or cracking on older, worn frames
• A noticeable difference in room temperature near the window versus elsewhere

Certification and Building Regulations

FENSA and CERTASS Explained

Here’s the part most homeowners don’t find out until they’ve already had three quotes: window replacement is notifiable work under Building Regulations Part L, but a FENSA-registered installer (or an installer registered under an equivalent scheme like CERTASS) can self-certify the work, avoiding a separate, often slower, building control inspection. 

FENSA registration confirms the installer meets current Building Regulations compliance standards for thermal performance and safety, genuinely worth checking, not just a badge on a website.

If your property is listed or sits in a conservation area, standard FENSA-covered work may not apply in the same way; Listed Building Consent and sometimes planning permission can be required instead, particularly around frame colour and materials on street-facing elevations. 

This is a genuine area of confusion, and it’s worth checking with your local planning department directly rather than relying on general guidance, including this one.

What Every Quote Should Include

• FENSA (or equivalent competent-person scheme) registration number
• Whether the quote is supply-only or supply-and-fit
• What’s included: scaffolding, disposal, making good
• The stated guarantee period and what it actually covers
• Whether manufacturing is in-house or subcontracted

How to Get the Best Double Glazing Cost

Comparing Multiple Quotes

Getting three quotes helps you spot which installer is pricing fairly and which is either cutting corners or padding the figure, but only if you’re comparing like-for-like scope, not just a bottom-line number.

Timing Your Purchase for a Better Price

Installers’ diaries often ease slightly outside the busiest spring and early-autumn booking periods, which can mean more flexible survey slots, though this isn’t a fixed rule, and it varies year to year.

A Real Example: Two Very Different Buckinghamshire Jobs

A homeowner near Aylesbury town centre, in a Victorian terrace with a bay window and on-street parking restrictions, is dealing with a genuinely different job than a homeowner on a modern estate near Milton Keynes. 

The terrace job often needs a permit for the delivery vehicle, careful access through a narrow frontage, and possibly heritage-matched frame colours if it’s in a conservation area, all of which can extend the timeline by a few days. The new-build estate job, by contrast, usually has driveway access, standard-size openings, and a more predictable 1–2 day install.

The same pattern holds further west into Oxfordshire: a period cottage near Banbury or a conservation-area property closer to Oxford’s city centre will typically face similar access and heritage considerations to a comparable Buckinghamshire terrace, while newer estates around Bicester tend to mirror the more straightforward Milton Keynes scenario.

One honest limitation worth naming: on very narrow Victorian bay fronts, a full flush sash replacement isn’t always the ideal fit if the existing sightlines are already tight; a standard casement approach can sometimes preserve more usable light than trying to force a flush sash profile into a constrained opening. It’s worth raising this specifically at survey stage rather than assuming one style suits every period frontage.

Our team is based in Buckinghamshire and manufactures every window in-house, and backing it with a 10-year guarantee. Visit our Flush Sash page to see the full range, or go straight to Contact Us to book your survey.