Last updated: November 2026
Sash windows in London cost £1,440 to £1,800 per window for new double glazed sashes in your existing frames, and £2,280 to £2,880 per window for a complete new window. A draught seal and overhaul of your existing windows costs £480 to £840 per window. All prices include VAT and installation.
If you have started pricing up sash windows, the quotes can be hard to compare. One company says £1,200 a window, another says £3,000, and it is not clear what sits behind either number.
This page sets out what we charge, what each price includes, and what moves it up or down. Every figure comes from our current price list, so you can plan a budget before anyone visits your home.
Sash window prices at a glance
| Service | What we do | Price per window inc. VAT | Price per window ex. VAT |
|---|---|---|---|
| Draught seal and overhaul | Keep your windows, fit new draught-sealed beads, re-cord the sashes and fit new locks | £480 to £840 | £400 to £700 |
| New double glazed sashes | Make new double glazed sashes by hand and fit them into your existing box frames | £1,440 to £1,800 | £1,200 to £1,500 |
| Complete replacement | Make a new frame and double glazed sashes, and replace the whole window | £2,280 to £2,880 | £1,900 to £2,400 |
| Vacuum glass upgrade | Use vacuum glass instead of standard double glazing, in new sashes or a complete window | £600 extra | £500 extra |
A simple window with no glazing bars sits at the lower end of each range. Glazing bars, curved tops and larger sizes move a window towards the upper end.
A note on VAT: our online quote shows guide prices before VAT. Add 20% to compare them with the prices on this page.
What the price includes
For new sashes and complete replacement windows, every price includes:
- a free survey, where we check your frames and measure every window
- sashes or windows made by hand in our British workshops
- toughened double glazing as standard
- a spray-painted finish, applied in the workshop
- new cords or spiral balances, draught seals, a sash lock and roller stops
- installation by our own fitters, and removal of your old sashes or windows
- a 10-year insurance-backed guarantee
- a FENSA certificate for every complete replacement, which you will need when you sell your home
Where we replace the whole window, we make good the plaster to a standard ready for you to decorate.
A draught seal and overhaul includes new staff and parting beads with built-in draught seals, new cords, and new or refitted locks. It does not include painting.
What affects the cost of a sash window?
Design affects the price more than size does. Materials make up only about 5 to 10% of the cost of a sash window. Most of the cost is the time it takes to make it by hand. Doubling the size of a window may add only about 10%, while a complex design can add far more.
These are the main factors:
- Glazing bars. A plain one-over-one sash is the quickest to make. Six-over-six or Georgian patterns take much longer.
- Shape. Curved or arched tops need extra joinery time.
- Bays and combination frames. Bay windows and double frames take longer to make and fit.
- Glass. Vacuum glass and acoustic glass cost more than standard double glazing.
- Timber. Hardwoods cost more than our standard softwood.
- Finish and ironmongery. A custom paint colour, different colours inside and out, or bespoke locks and lifts add to the price.
- Access. Upper floors, scaffolding or difficult parking can add time on site.
- Extra work. Painting your existing frames, removing shutters or replacing pulley wheels adds to the price.
Glass upgrades
Vacuum glass adds about £600 per window, including VAT. It is around 8.3mm thick, so it keeps the slim look of single glazing, and it insulates better than double glazing. We fit vacuum glass in new sashes and complete windows only, never in your existing sashes. Read more about vacuum insulated glass.
Acoustic glass reduces noise from busy roads and flight paths. It adds around £250 to £400 per window, including VAT.
Timber choices
- Redwood is our standard softwood, and all prices on this page are for Redwood.
- Utile hardwood adds about 10%. It takes paint particularly well.
- Accoya adds about 20%. It is a treated timber with a 50-year manufacturer’s guarantee on the wood itself.
We do not use pine or oak.
Repair or replace: how the costs compare
A draught seal and overhaul is the cheapest way to make sound windows warmer and easier to open. At £480 to £840 per window, it costs a third to a half of the price of new sashes. You keep your single glazing, though, and most heat escapes through the glass.
Replacement makes sense when the timber has rotted, or when you want the warmth of double glazing. New sashes in your existing frames cost £1,440 to £1,800 per window. A complete new window costs £2,280 to £2,880.
Some specialist firms offer full restoration, stripping every window back to bare timber and re-glazing it. This typically costs £1,000 to £1,500 per window, and the window stays single glazed. We do not offer this service.
Not sure which you need? Read our repair or replace guide, or see our sash window repairs and draught proofing guide.
What our recent London projects cost
| Project | Work | Cost |
|---|---|---|
| Prince of Wales Drive, Battersea, SW11 | 15 new double glazed sashes in existing box frames, plus extra work on the frames | About £1,700 to £1,800 per window, ex. VAT |
| Bloom Park Road, Fulham, SW6 (2025) | 3 pairs of plain sashes in a basement bay, with the existing frames repainted | About £5,000 in total, inc. VAT |
| Cathles Road, SW12 (2025) | 5 windows with new sashes and 3 complete replacements, including a double combination frame | About £17,500 in total, inc. VAT |
| Oswyth Road, Denmark Hill, SE5 (2024) | 2 complete new box sash windows on the first floor | About £5,750 in total, inc. VAT |
See more examples in our case studies.
How to keep the cost down
- Keep your box frames. New sashes cost £840 to £1,080 less per window than a complete replacement. Our surveyor will tell you if your frames are sound.
- Choose a simpler design where it suits the house. Fewer glazing bars mean less time in the workshop.
- Draught seal sound windows instead of replacing them.
- Do the work in one go. One survey and one installation visit cost less than several small jobs.
We only supply and fit our windows ourselves. We do not offer supply only, because a badly fitted sash will stick, rattle or let in draughts.
Are timber sash windows more expensive than uPVC?
Yes, uPVC sash windows usually cost less to buy. We make timber windows only. Timber lasts for decades when it is painted and maintained, and it can be repaired rather than thrown away.
In conservation areas, councils often expect new windows to match the originals. Check with your local planning authority before you order. Read our timber vs uPVC comparison.
How long does it take?
Manufacture typically takes 12 to 14 weeks. It starts once we have your deposit, your signed specification and our final measurements. Once the windows are ready, our fitters usually install one to three windows a day.
Frequently asked questions
Timber sash windows cost £1,440 to £1,800 per window for new sashes in your existing frames, or £2,280 to £2,880 for a complete new window. Both prices include VAT and installation. Utile hardwood adds about 10%, and Accoya about 20%.
Most of our customers pay between £1,440 and £2,880 per window, including VAT and installation. The price depends on whether you keep your box frames, the window design and the glass you choose.
All our new sashes and windows are double glazed as standard. New double glazed sashes cost £1,440 to £1,800 per window, and complete double glazed windows cost £2,280 to £2,880, including VAT.
A draught seal and overhaul costs £480 to £840 per window, including VAT. It includes new draught-sealed beads, new cords and new or refitted locks.
Replacing the sashes only costs £1,440 to £1,800 per window. Replacing the whole window, frame and sashes, costs £2,280 to £2,880. Both prices include VAT, installation and our 10-year guarantee.
Design matters most, because glazing bars, curved tops and combination frames take longer to make. Glass upgrades, hardwood, custom finishes and difficult access also add to the price.
Vacuum glass adds about £600 per window, including VAT. We fit it in new sashes and complete windows only, never in existing sashes.
Yes, timber sash windows usually cost more to buy than uPVC. Timber lasts for decades when maintained, and it can be repaired rather than replaced.
Yes. Our online quote lets you choose your sash design and sizes, then emails you guide prices in minutes. Those guide prices exclude VAT.
Get your guide price
Our online quote works as a sash window cost calculator. Choose your sash design and sizes, and we will email you guide prices in minutes.
For an exact price, book a free survey. Call us on 020 7924 7303, contact us online, or visit our showroom on Fulham Road.