Wooden Sash Windows Cost

What timber sash windows cost by wood species, how softwood and hardwood compare on price and lifespan, and when restoration beats replacement.

Last reviewed: 2026-07-20 • 8 min read • Verified against 9 timber specialist quotes

Wooden Sash Window Costs by Species

Wood choice affects upfront cost, lifespan, maintenance frequency, and eligibility for listed building consent. Prices below are supply and fit including double glazing (January 2026).

All prices include 24mm double glazing, mechanical sash balances, sash fasteners, and installation. Add £140-£280 per window for draught proofing, £40-£70 for Georgian astragal bars.

Softwood vs Hardwood: Full Comparison

The softwood vs hardwood decision affects total cost over the life of the windows, not just upfront price. Here's the 25-year cost breakdown for a single window.

For a 10-window house over 25 years: softwood costs £25,100 total vs hardwood £27,900 total. If you're planning to keep the house 50+ years, hardwood wins because it can be maintained indefinitely. If you're selling within 20-30 years, softwood delivers adequate lifespan at lower cost.

Timber Species Deep Dive

Scandinavian Redwood (Best Value Softwood)

Slow-grown northern pine from Sweden, Norway, Finland. Tight grain, naturally rot-resistant, stable. The traditional choice for UK sash windows from 1850s onwards.

Cost: £900-£1,400 per window installed. Lifespan: 60-80 years with repainting every 5-7 years. Maintenance: Needs water-based exterior wood paint or microporous stain. Sills face south will need repair/replacement at 30-40 years (£200-£400 per window).

Choose redwood if you want authentic period sash windows at reasonable cost, and you're happy to repaint regularly.

European Oak (Best for Heritage Properties)

Quarter-sawn European oak. Dense, rot-proof, beautiful grain. The premium choice for listed buildings and high-end restorations.

Cost: £1,600-£2,400 per window installed. Lifespan: 80-120 years. Maintenance: Repaint every 8-10 years. Oak contains tannins that can stain if water sits on the surface, so use tannin-blocking primer.

Oak moves less than softwood (lower expansion/contraction with humidity changes), so Georgian bar joints stay tight and sashes don't stick as much in wet weather. The timber itself outlasts the paint and even the glass units (which fail after 20-30 years).

Choose oak for listed buildings, front elevations in conservation areas, or if you're building a house to last 100+ years.

Accoya (Best Longevity and Stability)

Radiata pine chemically modified (acetylated) to be rot-proof and dimensionally stable. Carries a 60-year above-ground warranty. Resists rot better than any natural timber.

Cost: £1,800-£2,600 per window installed. Lifespan: 100+ years. Maintenance: Repaint every 10-12 years (holds paint better than natural timber). No sill rot, no warping, no swelling in damp weather.

Accoya moves 75% less than standard softwood when humidity changes. This means sashes slide smoothly year-round and paint lasts longer (no cracking from timber movement). The downside: it's expensive upfront, and some conservation officers reject it for listed buildings (not a natural timber, lighter colour than oak/redwood).

Choose accoya if you want the lowest possible maintenance, live in a high-rainfall area (Wales, Scotland, northwest England), or have south-facing bays prone to timber failure.

Sapele (Mid-Range Hardwood)

African hardwood, reddish-brown, interlocked grain. Cheaper than oak but more durable than softwood.

Cost: £1,300-£1,900 per window installed. Lifespan: 70-90 years. Maintenance: Repaint every 7-9 years. Sapele can be temperamental (interlocked grain means it sometimes moves unpredictably, causing paint to crack). Choose quarter-sawn sapele if available (more stable).

Sapele makes sense if you want hardwood longevity without oak prices, and the property isn't listed (listed building officers often prefer European oak or native hardwoods).

Standard Pine (Avoid Unless Budget-Critical)

Fast-grown European pine (not Scandinavian slow-grown). Wide grain, knotty, prone to warping and rot.

Cost: £850-£1,200 per window installed. Lifespan: 50-70 years if well-maintained, often less. Problems: Knots fall out or weep resin, sills rot after 15-20 years, sashes warp if not kiln-dried properly.

Only choose cheap pine if you're planning to sell within 10-15 years and need the lowest possible outlay. For long-term ownership, spend the extra £200-£300 per window on redwood.

Restoration vs Replacement: When to Choose Each

If your existing sash windows are timber, you can often restore them instead of replacing. This affects cost, heritage value, and carbon footprint (restoring existing timber saves 80% of embodied carbon vs new manufacture).

Restore If:

• Less than 30% timber rot (rotten sections can be cut out and scarfed with new timber at £150-£400 per window)
• Listed building or conservation area (restoration preserves original fabric, often required for consent)
• Pre-1900 sashes with historical value (Georgian 6-over-6, early Victorian 2-over-2, original crown glass)
• Box frames are sound (even if sashes need work, replacing sashes alone is cheaper than full replacement)

Restoration cost: £600-£1,200 per window including sash removal, timber repair (splice or dutchman repair), re-glazing with slim double glazing, draught proofing, new cords/balances, repainting.

Replace If:

• More than 40% timber rot (frames or sashes structurally compromised)
• Sashes severely warped or twisted (often from poor original timber quality or water damage)
• Box frames rotten at the base (can't remove sashes without collapsing the frame)
• Restoration quote exceeds 75% of replacement cost (uneconomic to restore)
• Property is not listed and you want modern double glazing (24mm vs 14-18mm slim DG)

Replacement cost: £900-£2,400 per window depending on timber species and glazing spec.

Timber vs UPVC: Long-Term Cost Comparison

UPVC sash windows cost less upfront but can't be repaired at end of life. Timber costs more initially but can be maintained indefinitely. The crossover point is around 35-40 years.

Timber wins on 40+ year cost if you can do your own painting (saving £150-£250 per window per cycle). UPVC wins for 15-30 year ownership or if you never want to think about maintenance.

What Affects Wooden Sash Window Prices

Glazing Bar Pattern

Georgian 6-over-6 or Victorian 2-over-2 astragal bars (the grid dividing the glass) cost +£40-£80 per window for surface-bonded bars, or +£150-£280 per window for true divided lights (individual small panes with putty glazing, only available in timber).

Listed buildings often require true divided lights on front elevations. Modern bonded bars are rejected because they look wrong (thick plastic-looking bars vs slim 12mm timber muntins).

Paint Finish

• Standard exterior wood paint (acrylic): Included in base price. Lasts 5-7 years.
• Microporous paint or stain: +£40-£80 per window. Lets timber breathe, reduces flaking. Lasts 6-8 years.
• Linseed oil paint (heritage finish): +£400-£600 per window. Required by some listed building consents. Lasts 8-12 years but very expensive.

Sash Balance Type

• Traditional cord and weight: Included in base price. Authentic, repairable, lasts 20-30 years before cords need replacing (£120-£180 per window).
• Spiral balances: +£30-£60 per window. Easier to install, no pocket access needed. Less authentic appearance.
• Constant-force balances: +£80-£140 per window. Smoother operation, easier adjustment. Not appropriate for listed buildings.

Sources

Pricing verified against:

• The Sash Window Workshop timber species price list (trade, Jan 2026)
• Timbawood bespoke sash window quotes (softwood and hardwood, Southeast, Dec 2025)
• Ventrolla timber sash restoration vs replacement costs (London, 2025-2026)
• Accoya manufacturer guidance on lifespan and warranty (updated Jan 2026)
• Historic England advice on timber species for listed buildings (Oct 2025)
• MyBuilder painter quotes for external sash window repainting (2025-2026)