Most London sash window repairs cost between £80 and £190 per window. A small splice repair is £80, an overhaul with draught proofing is £188, and a replacement sash is £190. Full replacement costs far more, at £1,480. Here is what each price covers and why repair usually wins.
Our price list
We publish our prices because a free site visit and written quote should never come as a surprise. Every figure below is the price per window unless stated. VAT applies, because we are a VAT-registered company.
First, a small splice repair is £80. We cut out a patch of rot and fit new timber, so this suits localised damage. A bottom-rail repair is £120, which covers the rail that takes the worst of the weather.
Next, sill replacement is £120 per window. Rotten sills are a common fault. Sash re-cording and counterbalance work is also £120 per window, and you can read how it works in our guide to broken sash cord replacement.
Then there is the full overhaul with draught proofing, at £188 per window. We strip the sashes, repair what is worn, refit them and seal the gaps, as set out on our sash window overhaul page.
Finally, a replacement sash is £190, and it costs more for ornate or multi-bar designs. A new double-glazed sash in your original frame is £680. A full double-glazed replacement window is £1,480.
What drives the price
Condition is the biggest factor. A sash that only needs new cords and a clean costs far less than one with rot through the bottom rail. For that reason we look at every window before we quote.
Design also matters. For example, a plain two-over-two sash is quicker to work on than a multi-bar Georgian one. Each extra glazing bar adds joints, putty and paint, and that adds time.
However, access changes the cost as well. A ground-floor window is simple. A fourth-floor window on a mansion block needs more safety kit and more time, so the quote can change.
Finally, glass counts. Keeping your old glass costs less than fitting new units. If you want double glazing, we use Pilkington low-E glass. We cover it with a five-year guarantee on the sealed units.
Repair versus replace
Repair is nearly always cheaper, because you pay for labour on what is worn instead of a whole new unit. Compare a £188 overhaul with a £1,480 full replacement. Even a house with ten windows would see a large gap between the two.
Repair also keeps your original timber and glass. That said, some windows are past saving. If the frame itself has failed, we will tell you honestly.
Replacement can also cost you more than the invoice shows. For example, in a conservation area or on a listed home, you may need consent first. Our sash window repairs service is built around keeping what you have, which usually avoids that hurdle.
How the costs add up on a typical job
For example, take a Victorian terrace with six sash windows. Say four need an overhaul and draught proofing, and two need new sills as well. The overhauls come to 4 x £188, which is £752. The two sills add 2 x £120, which is £240, so the total is £992 plus VAT.
That example is only an illustration. Your own quote depends on what we find. However, it shows how a whole house can be brought back to good order for less than the price of one or two replacement windows.
We also suggest grouping jobs. If we are already on site, adding another window is quicker than a separate visit. As a result, a whole-house booking often makes more sense than fixing one window now and another next year.
Cheap fixes that cost more later
A quick paint-over of a rotten sill looks fine for a season. However, the rot keeps spreading underneath, so you pay again within a year or two. Filler on a rail has the same problem.
Ignoring a broken cord is another false saving, because the weight sits loose in the box, and the sash can drop without warning. For more on this, see our guide to spotting the signs your sash windows need repair.
Heat loss is a running cost, too, because gaps around a sash let warm air escape all winter. Our comparison of draught proofing against secondary glazing shows which fix suits which problem.
Listed and conservation-area homes
If your home is listed, the rules change. Listed building consent can add time and cost. Our guide to double glazing listed sash windows explains what councils tend to expect.
We handle listed and conservation work case by case. We also keep the repairs like-for-like wherever we can. In other words, we match the original profiles so the window still looks right from the street.
Condensation and other extras
Some jobs bring extra checks. For example, misted or wet glass can point to a ventilation problem or a failed seal. Our post on sash window condensation covers the causes before you spend anything.
Local examples
The same price list applies across London. Even so, the mix of work differs by area. Terraced streets need plenty of sill and rail repairs, so sash window repairs in Wandsworth often include both.
Tall period townhouses have heavier sashes and more ornate bars. For that reason, sash windows across Kensington and Chelsea can need ornate-sash pricing. Meanwhile, homes across Islington range from Georgian terraces to converted warehouses.
Getting an exact quote
First, use our contact form. Tell us your postcode, how many windows you have and what is wrong. We then arrange a free site visit and send a written quote.
The quote lists each window and each job, so you can see where every pound goes. There is no obligation to proceed. If you do, the five-year no-quibble guarantee on labour and the draught-proofing system applies.
You can send us your details any time, and we reply during working hours, Monday to Friday, 08:00 to 18:00. Instead of waiting, act early. A small repair today is usually a £80 to £190 job, while a neglected window can become a £1,480 one.