Sash window repair in London, done as the joiners intended.

Repair, or restoration? Two different jobs.

A London sash window is a machine of a hundred and fifty parts (two sashes, two weights, four cords, pulleys, beads and a box frame), and most "broken" sash windows only need one of those parts putting right. That is a repair: an hour or two on site, the window working again the same day. Sash window restoration is the deeper discipline: the full overhaul that takes a tired Victorian window back to smooth, quiet, weathertight service for another generation.

We quote both routes where both are viable, with the difference in cost and lifespan set out plainly.

The five faults every London sash window develops

1. Broken cords & unbalanced weights

   The classic failure: a cord snaps and the sash slams or won't stay open. We open the pockets, re-cord in waxed cord, and check the cast-iron weights actually match the sash (they often don't after a century of reglazing).

2. Rattling sashes

   Worn beads and shrunken timber leave the sash loose in its channels. Re-set beads and a brush-pile draught-proofing system hold the sash snug, silent in wind, still gliding freely.

3. Rot in sills, rails & box frames

   Bottom rails and sills take the weather first. We cut back to sound timber and splice in new sections: a proper scarfed repair, not filler, preserving the original joinery around it.

4. Stuck & painted-shut sashes

   Decades of paint bind sash to frame. We split the paint lines, ease the channels, wax the runs and leave you a window that opens for the first time in years.

5. Draughts & heat loss

   The gaps that make a sash window work are the gaps that let winter in. Sealed properly (section III), a sash window keeps its charm and loses the chill.

The double-glazed sash upgrade

Where sashes are deep enough (most late-Victorian and Edwardian joinery is), the original single panes can be replaced with slim double-glazed units of around 12-14 mm overall thickness, glazed into the existing rebates with heritage putty profiles. The weights are re-balanced for the heavier glass, the sightlines stay original, and from the street nothing has changed except the comfort inside. Where the sashes are too slender, we say so, and offer new double-glazed timber sashes in the original pattern through our sash window installation team, or secondary glazing where originality is paramount.

Conservation areas & period streets

Much of our sash work sits in conservation areas: the terraces of Islington, Camden, Haringey, Hackney and beyond. Like-for-like repair and draught proofing almost never need permission; alterations such as double glazing an original sash sometimes do, and listed buildings always deserve a conversation with the conservation officer first. We work to the principle conservation bodies ask for: repair rather than replace, and keep every sound piece of original fabric. It is also, conveniently, the cheapest honest answer: the same repair-first promise that runs through all our window and door repairs.

Modern frames more your thing? See our uPVC window repairs and uPVC door repairs, and for glass smashed tonight, our 24/7 emergency glazing team answers at any hour.