Draught-proofing original sashes vs replacing: an honest guide

We sell replacement windows, so read this with that in mind — and then notice that we're about to talk you out of buying some.

Sometimes the originals should stay. A Victorian sash with sound timber is a remarkable survivor: slow-grown timber of a quality that's genuinely hard to buy now, with a century of proof it suits your wall. If the frames are solid, the sashes run, and your main complaints are draughts and rattles, refurbishment plus draught-proofing is often the right answer — brush seals routed into the sashes, new cords, easing and adjustment. It's a fraction of the cost of replacement, it keeps original fabric (which conservation officers love), and a well-draught-proofed original is dramatically less draughty than its reputation.

What draught-proofing can't fix. It can't fix rot — probe the bottom rails and sills with a screwdriver; softness means trouble that spreads. It can't fix single glazing's heat loss: seals stop moving air, but single glass still leaks warmth many times faster than a modern sealed unit U-values explained. It can't do much for street noise, and it can't help windows that have been butchered by previous "repairs" into more filler than timber.

The honest decision test. Refurbish if: timber is sound, the pattern is original and lovely, budget is tight, or the conservation context values original fabric above all. Replace if: rot has real hold, you're heating the house through the glass, noise is wearing you down, or the existing windows are already poor replacements of the originals — there's no heritage in preserving a 1980s mistake.

And the middle path. Plenty of houses need both: refurbish the sound windows on the sheltered side, replace the rotten ones on the weather side — matched to the originals, which is exactly what made-to-measure is for. If you send us photos, we'll tell you honestly which of yours we'd keep. Get in touch