Window repairs

The short answer

Traditional sash and case windows can almost always be repaired rather than replaced: cords, pulleys, beads, splice repairs to decayed timber, new putty and draughtproofing brushes. Modern double glazing more often needs the sealed unit replaced when it mists, or the hinges and locks refurbished. Repair is usually cheaper than replacement and, on listed or conservation-area property, often the only permitted route.

What the work involves

Overhaul typically means removing the sashes, renewing cords and pulleys, splicing in new timber where rot has taken hold, re-puttying, easing and rebalancing, fitting brush draughtproofing to the meeting rails and stiles, and redecorating.

Rules and consents in Scotland

Replacing windows on a listed building needs listed building consent; in conservation areas, replacement usually has to match the original in material and pattern. Repair and draughtproofing generally need no consent. Replacement windows must meet current energy standards under building regulations.

What commonly goes wrong

Replacing repairable sash windows with uPVC in a conservation area without consent, which can lead to enforcement action as well as a poorer result.

What it usually costs

Indicative ranges only, to help you judge a quote. They are not an estimate for your property — only the business doing the work can give you that.

• Draughtproofing and overhaul per window is a fraction of the cost of replacement.
• Timber splice repairs add cost where the bottom rail or cill has decayed.
• Slim-profile double glazing in existing sashes costs more than secondary glazing but keeps the original appearance.
• Replacement sash and case windows in timber cost several times the price of an overhaul.

What to do, in order

1. 1Check whether the property is listed or in a conservation area before considering replacement.
2. 2Have each window assessed individually — condition often varies across an elevation.
3. 3Prioritise the worst-affected and most exposed windows if phasing the work.
4. 4Ask whether draughtproofing includes rebalancing the sashes.
5. 5Consider secondary glazing where slim double glazing is not permitted.
6. 6Keep external decoration up to date afterwards — paint is what protects the timber.

Local detail for the Lothians

• Sash and case windows are the standard across Edinburgh's pre-1919 stock, and the New Town, Old Town and many suburban conservation areas require them to be retained.
• Specialist sash window firms in Edinburgh are used to working within listed building constraints and to Historic Environment Scotland guidance.
• Exposed west-facing tenement elevations decay faster at the cill and bottom rail.
• Secondary glazing is often the accepted compromise in the World Heritage Site where slim double glazing is refused.

When you need a professional

A joiner or specialist sash window company; a conservation officer or architect where consent is involved.

Common questions

Can sash windows be draughtproofed effectively?

Yes — brush seals fitted during an overhaul reduce draughts and rattling substantially while keeping the original windows.

My double glazing is misted — do I need new windows?

Usually not. The sealed unit can normally be replaced within the existing frame.

Related pages

• Exterior painting and decoration

  Protecting windows, doors and rainwater goods on exposed Scottish elevations.

• Condensation and mould

  Ventilation, heating patterns and cold spots — the most common damp complaint.

• Damp problems

  Telling penetrating damp, condensation and rising damp apart before spending money.