How much does double glazing sash windows cost?

Double glazing sash windows in London costs £650–£1,300 per window to retrofit double-glazed units into your existing sashes. If new sashes are required, costs rise to £850–£2,000 per window. A full replacement double-glazed sash window (new frame and sashes) starts from £2,400. All prices exclude VAT.

How much does sash window replacement cost?

New sash window replacement in London starts from £2,400 per window for a standard timber double-glazed sash. Bay windows (3 sashes) start from £4,900. Prices vary based on size, timber species (softwood vs hardwood), glazing type, and whether the box frame needs replacing. We always recommend repair or restoration where possible as it's significantly more cost-effective.

How much does sash window restoration cost?

Sash window restoration (full overhaul) starts from £1,950 per window. This includes removing both sashes, replacing all cords and pulleys, repairing minor timber defects, counterbalancing and refitting, plus a full draught-proof system — excellent value versus replacement.

What affects sash window prices in London?

Key factors that affect sash window costs in London include: window size (small, large, Venetian/bay), condition of existing timber (rot extent, number of rails needing replacement), glazing type (single, double, triple), access difficulties (upper floors, restricted parking, no CPZ), timber species (softwood vs hardwood), conservation area or listed building requirements, and whether draught proofing or decoration is included.

Do sash window prices include VAT?

All prices on this page are exclusive of VAT. VAT at 20% is added to the final invoice. Your free site survey quote will clearly show prices both ex-VAT and inc-VAT so there are no surprises.

How much is an emergency sash window repair in London?

Emergency same-day sash window repair in London starts from £800 including the first two hours of labour. This covers broken glass boarding, stuck or open windows, and immediate security make-safe. Call us on 02034881695 for emergency availability.

Transparent Pricing — No Hidden Extras

Sash Window Prices London

Q: How much does sash window draught proofing cost?

Sash window draught proofing in London starts from £950 per small to medium window and from £1,100 per large window. This includes removing the sash, machining draught-proof channels, fitting new pile seal, replacing sash cords and counterbalancing. A typical London Victorian home with 8 windows would start from £7,600.

Q: Is it cheaper to repair or replace sash windows?

Repair is almost always cheaper than replacement. A full sash window repair starts from £500 per window and restoration starts from £1,950, versus £2,400 for a new replacement window. Original Victorian and Edwardian timber sash windows are also made from slow-grown, dense timber that outlasts modern softwood when properly maintained. We always advise repair where structurally viable.

Q: How much do sash windows cost for a conservation area property?

Sash window work in conservation areas in London doesn't necessarily cost more — the key difference is that replacements must use like-for-like timber and glazing bar profiles. We are experienced in conservation area and listed building work and will advise on what's required during your free site survey. Repair and restoration pricing is unchanged; bespoke replacement sashes for listed buildings may attract a 10–20% premium depending on the specification.

Clear Costs. Free Site Survey. 2026.

Sash window prices London-wide vary from job to job — but you deserve to know what to expect before anyone knocks on your door. Here are our honest 2026 prices for repair, draught proofing, double glazing, restoration and replacement. All prices exclude VAT.

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At a Glance

Sash Window Cost Guide — London 2026

Sash window prices London depend on the work involved — here are our starting prices per window. Final cost confirmed after your free site survey.

🔧

Repair

from £500

per window

🌬️

Draught Proofing

from £950

per window

🏠

Restoration

from £1,950

per window

🪟

Double Glazing

from £650

per window

✨

Replacement

from £2,400

per window

All prices shown exclude VAT at 20%. Your written quote will show both ex-VAT and inc-VAT figures.

How Sash Window Prices London Are Calculated

We don't price from a call or a photo. Sash window prices London-wide differ from job to job — different timber condition, different box frame construction, different access logistics. That's why every quote starts with a free, no-obligation site survey where we assess your exact windows before giving you a written price.

Free Site Survey

We visit your property, inspect every window, and assess timber condition, access, and glazing requirements. No charge, no obligation.

Written Quote

You receive a detailed written quote within 48 hours. Line-by-line breakdown, both ex-VAT and inc-VAT, with no hidden extras.

You Decide

No pressure. You choose when to proceed. If you need us to phase the work across windows or budget periods, we're happy to do that.

🔧

Sash Window Repair Costs London

Most sash window problems in London are repairable for far less than replacement. Sash window repair prices depend on the fault, the extent of any timber decay, and the size of the window. Below are our standard 2026 repair prices. Where a repair's cost varies significantly with window size, we show it broken down by Small/standard (a typical single sash up to around 1.2m), Large (taller sashes or ground-floor windows up to around 2m), and Bay/multi-light (bay windows or windows with multiple sashes); otherwise we show a single starting price confirmed at your free site survey.

Repair Type	What's Included	Price (ex VAT)
Sash Cord Replacement Standard window, up to 2000mm	Remove sash, fit new cords, counterbalance, refit All four cords replaced Pulley lubrication Sash re-fitted and tested	£450
Sash Cord Replacement Large sash, over 2000mm (2m)	Same process as standard — higher price reflects heavier-duty cord and extra care rehanging a larger sash All four cords replaced Pulley lubrication	£580
Lead Weight Adding / Replacing	Where a counterweight is corroded, undersized, or missing, per weight Correctly sized lead weight fitted Balance re-tested	£250
Spring/Spiral Balance Assessment Visit For windows without traditional cords	We identify the correct balance rating for your window before ordering parts Balance type and rating confirmed Fee deducted from job if you proceed	£120
Spring/Spiral Balance Replacement	Correctly-rated replacement balance fitted and tested per window Matched to assessed rating Sash re-fitted and tested	From £385
Stuck or Painted-Shut Window	Free sash, plane timber, re-fit to run smoothly Sash freed without damaging frame Minor planing as required	Starts From £180
Broken Glass Replacement Single glazed	Remove broken pane, reglaze with matching glass, re-putty Like-for-like single pane replacement Putty made good and primed	Starts From £325
Broken Glass Replacement Double glazed	Remove broken unit, reglaze with matching double glazed unit, re-putty Slimline double glazed unit Putty made good and primed	Starts From £540
Timber Rot Repair (Resin)	Cut out decayed timber, consolidate and fill with 2-part epoxy resin Primed on completion Suitable for minor to moderate decay	Get a Quote
Sill Splice / Partial Sill Repair	Remove rotten section, splice in matching timber, prime Softwood or hardwood splice Left primed and undercoated	Get a Quote
Full Sill Replacement	Remove and replace entire window sill, rebed and prime Softwood standard; hardwood +20% Left primed and undercoated	Get a Quote
Lower Rail Replacement	Remove decayed bottom rail, fit new like-for-like rail Matched to existing profile Primed on completion	Get a Quote
Stile / Front Cheek Repair	Cut out and replace decayed stile sections or front cheeks Structural repair, primed finish Often combined with sill replacement	Get a Quote
New Sash Replacement Existing sash beyond repair	Manufacture and fit new sash to match original, single glazed Matched glazing bars and profile Primed and undercoated	Get a Quote

Important: Sash window repair costs in London can vary significantly depending on how many windows need attention, access to your property, and the extent of timber decay. Our sash window repair service always starts with a free site survey — we'll tell you exactly what's needed before any work begins.

🌬️

Sash Window Draught Proofing Prices London

Sash window draught proofing is the single most cost-effective upgrade for a draughty London period home. It eliminates cold air infiltration, reduces noise, and improves energy efficiency — without removing original timber or disturbing character features.

Window Type	What's Included	Price (ex VAT)
Small / Medium Sash Window Under 1.8m height, under 0.9m width	Full sash removal, draught-proof channels machined to sash and frame, new pile seal fitted, sash cords replaced, counterbalanced, refitted and tested Replacement sash cords included New Brighton fastener and sash lifts Security restrictors available (£40/set extra)	Get a Quote
Large Sash Window Over 1.8m height or over 0.9m width	Same process as above — higher price reflects additional labour for larger sash weight and machining time Counterbalance weights adjusted as required All hardware included	Get a Quote
Venetian Sash Window Two fixed side panels, one central sash	More complex frame construction requiring additional machining and bespoke cord routing All three panels addressed Custom cord routing through head of frame	Get a Quote
Spiral Balance Sash Window Spring-loaded channels, no traditional cords	Draught proofing adapted for spiral balance windows; balances inspected and replaced where worn Balance replacement if required (extra) Standard draught proofing process	Get a Quote
Draught Proofing + Full Decoration Complete package inc. internal + external paint	Full draught proof service plus internal and external decoration — ideal when scaffold would otherwise be required for external access Bare timber primed, undercoated, one gloss coat Dulux Weathershield used externally	Get a Quote

Note on decoration: All draught proofing requires some touch-up decoration after installation — channels are machined into the existing timber which exposes bare wood. If your windows were in good decorative order beforehand, minor touching-in is all that's needed. If they needed repainting anyway, the combined service (above) represents exceptional value versus using scaffold.

🏠

Sash Window Restoration & Refurbishment Costs

A full sash window restoration returns your original windows to fully functioning, draught-free condition — preserving the character of your period property at typically less than replacement cost. Sash window refurbishment in London starts from £1,950 per window. Ideal for London Victorian, Edwardian and Georgian homes.

Service	What's Included	Price (ex VAT)
Full Window Overhaul Cords, pulleys, counterbalance only	Both sashes removed, new sash cords fitted, pulleys lubricated, perished putty replaced, counterbalanced, refitted and tested New cords and pulleys Minor timber defects made good	Get a Quote
Full Restoration with Draught Proofing Recommended — best value per window	Complete overhaul plus machined draught-proof system, new pile seal, new hardware Everything in overhaul above Draught-proof channels machined and fitted New Brighton fastener, sash lifts, and security restrictors	Get a Quote
Full Restoration + Decoration Package Complete sash window refurbishment	All of the above plus full internal and external decoration to a gloss finish Timber stripped, primed, undercoated and top-coated Dulux Weathershield externally Eliminates need for scaffold	Get a Quote

Why restoration beats replacement: Original Victorian and Edwardian sash windows were made from slow-grown, dense old-growth timber that modern softwood cannot match. A properly restored original window will outlast a modern replacement if maintained — and typically costs less. We always recommend restoration where the frames are structurally sound.

🪟

Double Glazed Sash Windows Cost London

You can add double glazing to existing sash windows without replacing the whole frame. We offer two routes: retrofitting double-glazed units into your existing sashes (cheaper, quicker) or manufacturing new double-glazed sashes to fit your original box frames. Both are far more cost-effective than full replacement.

Service	What's Included	Price (ex VAT)
Double Glazing Retrofit DG units fitted into your existing sashes	Single glazing removed, sash rebated, argon-filled DG unit installed, putty finished Standard argon-filled, A-rated units Counterbalance adjusted for extra weight Draught proofing additional (see above)	Get a Quote
New Double-Glazed Sashes in Original Frame New sashes manufactured, original frame kept	New softwood sashes manufactured to match existing profile, double glazed, fitted into original box frame Like-for-like glazing bar profile Argon-filled DG units as standard Suitable for conservation areas	Get a Quote
Double-Glazed Bay Window 3-sash bay — new sashes in original frames	Three new double-glazed sashes manufactured and fitted into original bay frames; includes draught proofing Full bay addressed as one project Price includes draught proofing	Get a Quote
Acoustic / Laminated Glazing Upgrade For noise reduction on busy London roads	As per retrofit or new sash service above, but using acoustic laminated glass for maximum noise attenuation Up to 45dB noise reduction Suitable for conservation areas Planning approval not usually required	Get a Quote

Conservation areas: Double glazing in conservation areas is permitted under permitted development in England provided the glazing bars match the original profile and slim (6mm or less) spacer bars are used. We specify slim-bar units as standard. We can advise during your site survey whether planning consent is needed for your specific property.

✨

New Sash Window Replacement Cost London

Full sash window replacement — new frame, new sashes, new glass — is the most expensive option and only recommended where the existing box frames are structurally beyond repair. New sash windows start from £2,400 per window in London for bespoke softwood double-glazed units; Accoya® hardwood adds approximately 30–40%.

Window Type	What's Included	Price (ex VAT)
Standard Replacement Sash Window New frame + sashes, softwood, DG	Full box frame and sash replacement — bespoke joinery manufactured to match existing openings, double glazed, draught proofed FENSA certificate included Primed and undercoated Draught proofing included	Get a Quote
Bay Window Replacement 3-sash bay, new frames and sashes	All three windows in a typical Victorian bay replaced — new frames, new double-glazed sashes, draught proofed FENSA certificates for all windows Primed and undercoated	Get a Quote
Accoya® Hardwood Replacement Modified wood — 50-year durability	Full replacement as above but using Accoya® modified timber — industry-leading stability, 50-year above-ground guarantee Approved Accoya® manufacturer Ideal for conservation areas Best long-term value	Get a Quote

We'll always tell you if repair is possible first. Full replacement is only recommended where the box frame is structurally compromised beyond repair. In our experience, over 80% of London sash windows presented to us as "needing replacement" can be repaired or restored for significantly less. Book your free survey and we'll give you an honest assessment.

🚨

Emergency Sash Window Call-Out Costs London

Broken glass, sash stuck wide open in winter, or a security breach — we offer same-day emergency response across London. Call us on 02034881695.

Service	What's Included	Price (ex VAT)
Emergency Call-Out Same-day, includes first 2 hours labour	Priority attendance within 2–4 hours across Greater London; boarding, make-safe, and emergency repair where possible Broken glass boarding Stuck window freed Security make-safe	Call Us

Emergency? Call us now on 02034881695. We'll advise availability and confirm a time. Emergency pricing is based on a minimum 2-hour attendance; additional labour is charged at our standard hourly rate.

Sash Window Repair vs Restore vs Replace — Cost Comparison

Not sure which route is right for you? This table compares the three main options for a typical London Victorian sash window. Restoration almost always offers the best value — and in a conservation area it's often the only option anyway.

Criteria	Restore & Draught Proof	Repair Only	Full Replacement
Typical cost per window	Starts From £1,950	Starts From £500	Starts From £2,400
Eliminates draughts	✓	Partial	✓
Preserves original timber	✓	✓	✗
Suitable for conservation areas	✓	✓	Sometimes
Improves energy efficiency	✓	Minimal	✓
Disruption / time on site	1–2 days per property	½–1 day	3–5 days+
Expected lifespan after work	30–50+ years	10–20 years	25–40 years
Planning consent required	✗ No	✗ No	Sometimes

What Affects Sash Window Prices London Homeowners Pay?

Sash window costs vary. Here are the main factors that influence your final quote — we cover all of these in your free site survey.

📐

Window Size

Larger sashes take more time to machine, cord and counterbalance. Venetian or bay windows add complexity and therefore cost. Standard Victorian sash sizes attract the mid-range pricing shown above.

🪵

Timber Condition

Superficial rot can be repaired cheaply with epoxy resin. Structural decay in rails, sills or stiles requires new timber — more labour and materials. We assess this at your free site survey.

🏛️

Conservation Area / Listed Building

Repair and draught proofing costs are unchanged in conservation areas. Bespoke replacements must match original profiles — potentially a 10–20% premium. We're experienced in listed building work.

🚗

Parking & Access

No convenient parking in a CPZ or red route means longer time on site. Upper-floor windows on tall London townhouses may require equipment. We flag access factors clearly in your quote.

🪟

Glazing Type

Single glazing is cheapest. Standard argon-filled DG units are our default for double glazing. Acoustic laminated glass or heritage slim-bar units for conservation areas attract a 15–25% premium.

🌳

Timber Species

Softwood (our standard) is the most cost-effective. Hardwood adds approximately 20–35%. Accoya® modified timber — our premium choice — adds 30–40% but carries a 50-year guarantee and is ideal for conservation areas.

🔢

Number of Windows

Projects with 4+ windows attract better per-window pricing as mobilisation, parking and van costs are spread across more units. We'll confirm the project rate in your written quote.

🎨

Decoration

Painting is always additional unless you select our decoration package. Having us decorate while windows are removed saves considerable cost versus returning later with scaffold for external access.

⚡

Urgency

Standard scheduled work uses the pricing on this page. Same-day emergency attendance carries an additional call-out charge from £800 including the first two hours on site.

Sash Window Cost — Frequently Asked Questions

The most common questions we get about sash window prices in London, answered honestly.

How much are sash windows in London?

As a rough guide, sash windows in London start from £500 for a repair, £950 for draught proofing, £1,950 for restoration, and £2,400 for a new replacement window. The cost of sash windows depends on the work needed, the window size and the timber chosen — your exact price is confirmed free at survey, with no hidden extras.

How much does sash window repair cost in London?

Sash window repair in London starts from £500 per window depending on the fault. A straightforward broken sash cord is £450, or £580 for a large sash over 2000mm. Adding or replacing a lead counterweight is £250. Spring or spiral balance replacement is from £385 (following a £120 assessment visit to confirm the correct rating). Timber rot repairs start from £180 for a sill splice. Broken glass replacement starts from £325 for single glazed and £540 for double glazed. Complex repairs like full sill or stile replacement cost £280–£550. All prices exclude VAT and are confirmed at your free site survey.

How much does sash window draught proofing cost?

Sash window draught proofing starts from £950 per small to medium window and from £1,100 per large window. A typical Victorian London terrace with 8 windows would start from £7,600 to fully draught proof. The cost includes sash removal, machining draught-proof channels, new pile seal, replacement sash cords, counterbalancing and new hardware. All prices exclude VAT.

How much do double glazed sash windows cost in London?

Retrofitting double-glazed units into your existing sashes costs £650–£1,300 per window. If new sashes are required (existing sashes beyond repair), cost rises to £850–£2,000 per window. A full replacement double-glazed sash window (new frame and sashes) starts from £2,400. Bay window DG projects typically cost £3,000–£5,500. All prices exclude VAT.

How much does it cost to replace sash windows?

New sash window replacement in London starts from £2,400 per window for a standard bespoke softwood double-glazed sash. Bay windows start from £4,900. Hardwood or Accoya® adds 30–40%. Full replacement is only recommended where the box frame is structurally compromised — in most cases, restoration is far better value and we'll always tell you which is appropriate.

Is it cheaper to repair or replace sash windows?

Repair and restoration is almost always significantly cheaper than replacement. A full restoration with draught proofing starts from £1,950 per window versus £2,400 for full replacement. Original Victorian sash timber is also far denser and more durable than modern softwood, so a properly restored original window will outlast a new replacement. We will always recommend the most cost-effective solution.

Do your sash window prices include VAT?

No — all prices on this page are exclusive of VAT (20%). Your written quote will clearly show both the ex-VAT and inc-VAT figures so there are absolutely no surprises on your invoice.

How much extra do sash windows cost in a conservation area?

Repair, overhaul and draught proofing costs are the same whether you're in a conservation area or not. Bespoke replacement sashes for conservation areas or listed buildings may attract a 10–20% premium to ensure the glazing bar profile and slim spacer bars match the original. We're highly experienced in conservation area and listed building work and will advise exactly what's needed at your free site survey.

What is the sash window price for a whole house in London?

A typical London Victorian terraced house with 8 sash windows, fully restored and draught proofed, starts from £15,600 (excluding VAT). This includes removing all sashes, fitting a full draught-proof system, replacing all sash cords, new hardware, and counterbalancing. Projects of this size receive preferential per-window pricing. Book a free survey for an accurate whole-house price.

How long does sash window work take?

A straightforward sash cord repair takes half a day. Full draught proofing of a whole London terrace (8 windows) typically takes 2–3 days. Full replacement windows require 3–5 days for a typical house as frames need to be manufactured in advance. We'll confirm a programme when we send your written quote.

Do I need to be at home while the work is carried out?

For most sash window work you'll need to be present on the first day to provide access and discuss any specific requirements. For subsequent days on larger projects, many clients leave a key — we're fully insured and our team are vetted professionals. We'll discuss your preferences during the survey visit.

Get Your Free Sash Window Price

Every job is different. Book your free, no-obligation site survey and we'll give you a detailed written quote — line by line, ex-VAT and inc-VAT — within 48 hours. No pushy sales, no surprises.

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