Sash Window Repair Costs: What Each Job Should Cost

Three firms look at the same first-floor sash with a snapped cord and quote £180, £480 and £900. None of them is necessarily trying it on. The difference is almost never the cord — it is whether the sash comes out or is worked in situ, whether there is a van space outside, whether the price assumes one window or six, and whether the firm has a minimum charge that swallows a small job whole. Understanding those four things is most of what you need to read a sash window quote properly.

What you are actually paying for

The materials on a typical sash repair are trivial. Waxed cotton cord costs a few pounds a window. A length of parting bead is a few pounds more. Even a full set of new lead weights is a modest number. What you are buying is a skilled pair of hands, the access to reach the window, and the time to put the window back together so it works for another thirty years.

That is why the price does not scale the way people expect. Taking a sash out is most of the labour. Once it is out, re-cording it, easing it, sealing it and painting the rebate add far less than doing any one of those jobs as a separate visit. A firm quoting £280 for one cord and £700 for a full overhaul of the same window is not contradicting itself.

Typical London prices, job by job

These are 2026 ranges drawn from published London specialist price lists and national cost guides. Treat them as the shape of the market, not a quotation: condition, borough, height and quantity all move them.

Two figures from real London price lists are worth quoting because they explain the small-job problem. One established firm publishes a minimum call-out of £500 plus VAT for standard work, and £940 plus VAT for the first two hours of an emergency visit. That is not greed; it is what a day of a skilled joiner's time costs once travel, congestion charge, parking and insurance are in it. If your job is one cord on one window, expect to be quoted against a half-day minimum somewhere.

Why the cost guides and the real quotes disagree

National cost guides put sash cord replacement at £70 to £150. London specialist price lists put the same job at £280 to £620. Both are honest. The guide figure is the marginal cost of a cord when someone is already there with the sash out and the beads off. The price-list figure is the cost of sending a two-person team to your house to do that one thing.

The practical consequence: batch the work. Four windows on one elevation done in one visit will usually come in at less per window than two windows done six months apart, sometimes dramatically so. If you know the front bedroom sashes are going the same way as the ones you are fixing, get them all quoted now even if you only do half.

Where the hours actually go

It helps to know what a joiner is costing out in his head. On a straightforward Victorian two-over-two, worked from inside on a ground floor, a full overhaul with draught-proofing runs roughly like this.

That is most of a day for one window if everything behaves, and perhaps three or four windows in a day once the team is set up on the same house and the beads are coming off cleanly. It is why the second and third window on the same visit are so much cheaper than the first, and why a quote for six windows on one elevation can land near the price of three done separately.

Anything unexpected lands on top of that. A weight that has come off its cord and dropped to the bottom of the box means opening the pocket and sometimes cutting an access hole low in the pulley stile. A sash whose joints have opened means glue, cramps and an overnight set, which usually means a second visit. Both are normal, and both should be flagged as provisional items rather than absorbed silently into a fixed price.

The condition questions that move a quote

When a joiner looks at a window, this is roughly what he is pricing.

1. Do the sashes come out cleanly? Painted-in beads that snap on removal mean new beads, cut and fitted.
2. How sound is the bottom rail? The bottom rail and the cill are where water sits. A soft rail turns a £300 overhaul into a £600 splicing job — the mechanics of piecing new timber into a rotten frame explain why it is slow work rather than difficult work.
3. Are the weights present and correct? Missing weights, or weights that were never right for the glass in the sash, mean rebalancing rather than just re-cording.
4. What is the paint situation? Twelve layers of paint, the lower ones lead-bearing, need stripping under controlled conditions before anything can be eased or repainted.
5. Is it a standard box sash? Curved heads, Venetian sashes with side lights, and spiral-balance windows all carry a premium, often 50 to 100% over a plain box sash.
6. Access again. Ground floor, first floor with internal access, or scaffold.

If a quote seems high and you cannot see why, ask which of those six is driving it. A straight answer to that question tells you a great deal about who you are dealing with.

VAT, certificates and the costs you can avoid

Repair work on a home is standard-rated at 20%, and any quote should say whether VAT is included — the gap between £600 and £600 plus VAT is £120 you did not budget for.

There is one exception worth knowing. Installing draught stripping counts as an energy-saving material for VAT purposes, and it is zero-rated in residential accommodation until 31 March 2027, after which it drops to a 5% reduced rate. Secondary glazing and double glazing get no such relief — HMRC lists them explicitly as standard-rated. So the labour and materials for a proper draught-proofing job can come to you without VAT on top, while glazing upgrades cannot. On a £600 job that is £120, which is more than most people assume the difference between quotes amounts to.

The other cost you avoid by repairing is compliance. Under Approved Document L, a controlled fitting means the entire window unit including the frame. The guidance is explicit that replacing glazing, or a window in its existing frame, is not providing a controlled fitting, and that such work does not need to meet the energy efficiency requirements. In plain terms: repairing your sashes, re-cording them, or even reglazing them in the original frames does not trigger building control, does not need a FENSA or Certass certificate, and carries no notification fee. Replace the whole window and it does — with the 1.4 W/(m²·K) or Window Energy Rating Band B standard to meet, and a certificate your solicitor will ask for at sale.

Repair or replace: where the line actually falls

The honest answer is that repair wins far more often than the replacement industry suggests, but not always.

Repair is the better buy when the frame and box are sound, the sashes hold together at the joints, and the problems are cords, beads, seals, putty and paint. That is the majority of London sash windows, including ones that look dreadful. A full refurbishment at £620 to £1,200 against a replacement at £1,300 to £3,400 is a straightforward decision, and it keeps original glass and original joinery that cannot be bought back.

Replacement starts to make sense when the boxes themselves are rotten through, when previous "repairs" have filled and skimmed over failing timber for years, or when a window has been so badly altered that the proportions are gone. Even then, get the frame assessed separately from the sashes — new sashes into a sound original box is a common middle path that people are rarely offered. Our fuller breakdowns of restoration costs room by room and what replacement really costs in London go further into both sides.

If the driver is heat and noise rather than condition, price the glazing question separately again: slim double glazing into existing sashes and secondary glazing per window solve different problems at different prices, and neither of them is a reason to throw away a sound window.

Getting a quote you can compare

Ask every firm for the same four things and the prices become comparable.

1. Itemised, not a single figure. Cords, beads, seals, timber repairs, glazing and decoration listed separately.
2. Sashes out or in situ? In-situ draught-proofing and in-situ cord work are cheaper and shorter-lived. Both are legitimate; you just need to know which you are buying.
3. What happens if rot is found? A fixed price with an hourly rate for discovered timber repairs is normal and fair. A fixed price that quietly assumes no rot is not.
4. VAT, access and making good — parking, tower hire, and who fills and repaints the reveals.

Then look at how the window has been described back to you. Anyone who has talked about the cill, the meeting rails and the parting bead has looked at your window. Anyone quoting from a photo has not.

For a sense of what is fixable before you invite anyone round, our guide to what can be saved and what genuinely needs replacing is a reasonable first pass, and our London sash window repair team quotes across all boroughs with the itemisation above as standard.