Cost of New Windows: What a Six-Window Quote Includes
A whole-house window quote runs from {cost:window-replacement:basic} to {cost:window-replacement:premium}. Here is what sits inside it and what costs extra.
The cost of new windows for a typical six-window job is £3,600 at mid-range, with a usual range of £2,800 – £4,700. Our basic tier is £3,250 and a premium specification reaches £14,200, all including 20% VAT.
That is the headline. The more useful question is what the price actually covers, because two quotes for "six windows" can differ by hundreds of pounds purely on what is left out. Our full figures are in the Replacement windows guide; this piece looks at reading a quote line by line.
How we build the six-window figure
We calculate each job as labour hours multiplied by local rates, plus materials, then check the result against market prices and real quotes. Our default job is six windows, so dividing the total by six gives a rough per-window price. Treat that as a guide only: a small casement and a large bay or French-style opening do not cost the same, and a quote that averages them can hide the real spread.
What is normally included
A sound whole-house quote should list:
- The frames and sealed glazing units, made to measure
- Removal of the old frames
- Fitting, sealing and fixing the new frames
- Standard handles, hinges and locks
- Internal and external sealant
If any of these is missing, ask. A cheap headline figure often leaves out the items below.
What is often extra
Trickle vents. Many new frames come without them unless you ask. Check whether vents are priced per window or included, and whether your existing rooms rely on them for background ventilation.
Sills and cills. Replacing a worn stone or timber sill, or fitting a new board inside, is usually an added line.
Making good. Plaster repairs, re-decorating reveals and filling around the frame are frequently excluded. If you have not budgeted for a decorator, see our Painting and decorating guide for what the finishing can add.
Old-window disposal. Some firms take the old frames away at no charge; others bill for it. Get this in writing.
Scaffolding or access. Upper-floor windows on a tall house may need a tower or scaffold, which is not a standard inclusion.
Special shapes and sizes. Arched, bay or oversized units cost more than standard rectangles.
Frame material changes the price
The frame you choose is the biggest single decision after the number of windows. Using our model's mid-range job as the baseline:
- uPVC: £3,600
- Aluminium (thermally broken): £4,750
- Composite: £9,900
- Timber: £9,550
- Aluminium-clad timber: £14,000
For the full table, with usual ranges and lifespans, see below.
| Material | Typical | Usual range | Lifespan |
|---|---|---|---|
| Vinyl / uPVC | £3,600 | £2,800 – £4,700 | 25-35 years |
| Aluminium (thermally broken) | £4,750 | £3,700 – £6,150 | 30-45 years |
| Timber | £9,550 | £7,450 – £12,400 | 30-60 years |
| Composite | £9,900 | £7,750 – £12,900 | 30-50 years |
| Aluminium-clad timber | £14,000 | £10,900 – £18,200 | 40-60 years |
A longer lifespan can justify a higher upfront figure, but only if you plan to stay in the house. For a quick like-for-like swap where cost matters most, uPVC is usually the practical choice; period homes or conservation settings may point you towards timber or clad timber.
Rules that affect your quote
Replacement windows must meet building regulations. A FENSA or CERTASS registered installer can self-certify the work, and you should receive a certificate. If your installer is not registered, the work may need to be notified to building control, which adds time and cost. Ask for the registration number before you sign.
Windows and energy bills
New double or triple glazing helps with heat loss, but windows are only one part of the picture. If you are weighing where to spend first, compare with our External wall insulation guide. Note that the government's 0% VAT relief on energy-saving materials applies to listed items such as insulation, heat pumps, solar panels and batteries; do not assume replacement windows qualify, and ask your installer to show the VAT treatment on the quote.
How to compare quotes
- Ask each firm to quote the same number of windows, same frame material and same glazing specification.
- Request a line-by-line breakdown: frames, fitting, vents, sills, making good, disposal.
- Confirm the FENSA or CERTASS registration.
- Check what guarantee covers both the product and the installation.
- Run the totals through our "is my quote fair" tool to see where it sits against the range above.
A quote well above the range is not necessarily wrong, since size, access and shape all matter. But it should be able to explain itself line by line.
The bottom line
Budget for the headline figure, then add a sensible allowance for the extras: vents, sills, making good and disposal. If a quote is silent on any of them, the price is probably not final.