It’s a question every Edinburgh homeowner with failing period windows eventually faces: is it time to repair, or should we just replace? The answer, for the vast majority of Edinburgh properties, is repair — and not just for cost reasons.
The Case for Repair
Edinburgh has over 140,000 pre-1919 properties. The original sash and case windows in most of these buildings were made from slow-grown European Redwood (Pinus sylvestris) with a density and durability that modern timber cannot match. When properly maintained, these windows last for generations. Most of what looks like terminal failure — dropped sashes, draughts, stiff operation — is actually straightforward mechanical failure: a broken cord, worn brushpile, seized pulley.
These are repairs, not replacements. A full overhaul of a two-sash window — new pre-stretched waxed cotton sash cord, 18mm brushpile draught seals, pulley lubrication, bead adjustment — typically costs £400–£700 and takes one day. It restores the window to full function and dramatically reduces draughts.
When Is Replacement Genuinely Necessary?
Replacement becomes necessary when structural failure is so extensive that the frame cannot be salvaged — typically when large sections of the frame, sill, or sub-sill have rotted to the point of complete structural compromise. Even then, a specialist can often splice in new timber sections rather than replacing the full frame. True irreparable failure is rarer than most window salespeople would have you believe.
Conservation Areas and Listed Buildings: Replacement Requires Consent
If your property is in one of Edinburgh’s 14 conservation areas or is a Category A or B listed building, replacing your sash windows will almost certainly require Listed Building Consent or Conservation Area Consent from Edinburgh City Council. Replacing original timber sash windows with uPVC or aluminium alternatives in these areas is routinely refused. Repair requires no consent whatsoever — making it not just the cheaper option, but often the only viable one.
Thermal Performance: Can Repaired Windows Match Double Glazing?
Professionally draught-proofed sash windows with 18mm brushpile seals can achieve U-values approaching 2.0 W/m²K — compared to a standard modern double-glazed unit at around 1.4–1.6 W/m²K. The difference in practice is minimal, and the draught proofing alone eliminates the cold air infiltration that causes most comfort complaints in period homes. Secondary glazing can be added to bring thermal performance even closer to double glazing, while remaining fully reversible.
For almost every Edinburgh home, repair and draught proofing is the right answer. See our full sash window repair service →
Related: Listed building sash window repairs | Draught proofing | Get a free quote