Sash Window Repair Cost

What to expect for professional sash window repairs in the UK, from cord replacement to full restoration.

Quick answer: Typical UK repair costs: broken cord replacement £80-150 per window, draught-proofing £150-250, rot splice repairs £200-400, reglazing £60-120 per pane, and full overhaul (cords, easing, draught-proofing, redecoration) £600-1,200 per window. Always cheaper than replacement (£1,800-3,500 for like-for-like timber units).

Last reviewed: 15 June 2026 | 3 min read | Based on 2026 UK contractor quotes

Repair cost breakdown

Cord replacement

£80-150 per window for professional work. Includes:

Removing staff beads to access sashes
Opening weight pockets
Fitting new cords (both sides of affected sash)
Rebalancing and testing

DIY cost: £15-25 for materials (cord, pocket screws). Labour is 2-3 hours per window for someone with basic carpentry skills.

Draught-proofing systems

£150-250 per window installed. Professional systems (Ventrolla, Mighton, etc.) use brush pile or compression seals routed into the timber. Eliminates rattling and significantly improves thermal performance without altering appearance.

Rot repairs

Depends on extent:

Minor splice repairs: £200-400 per window (bottom rail, corner repairs)
Sill replacement: £300-600 per window
Extensive repairs: £400-800 if multiple components affected

Timber must be matched (usually softwood for Georgian/Victorian, sometimes hardwood for quality work). Repairs should be scarfed or spliced, not face-patched with filler.

Reglazing

£60-120 per pane depending on glass type:

Float glass (modern): £40-60 per pane
Cylinder glass (hand-blown reproduction): £80-120 per pane
Decorative/colored glass: £150+ (specialist work)

Putty and labor included. For listed buildings, cylinder glass is often required.

Full overhaul

£600-1,200 per window. Includes:

Complete sash removal
Cord replacement (both sashes)
Easing and adjustment
Draught-proofing system
Minor timber repairs
Reglaze as needed
Redecoration (primer and undercoat)

Replacement costs (for comparison)

Like-for-like timber sash units: £1,800-3,500 per window supply and fit. Plus listed building consent fees (£206 minor, £407 major alterations). Payback for repair vs replacement: typically repair pays for itself within 5-10 years on thermal performance alone, ignoring heritage value.

Finding reputable contractors

Use the Historic England Master Craftsmen Register or SPAB members directory. Avoid companies that quote replacement before assessing repair feasibility.

Federation of Master Builders pricing guide 2026
Historic England repair case studies
SPAB contractor network