Wooden windows in Jersey take a beating from salt air, driving rain and winter south westerlies, so it is no surprise when frames start to look tired. The good news is that most timber windows can be repaired for a fraction of the cost of replacement. Here is how to work out which side of the line yours fall on.
Take a blunt screwdriver and press it gently into the timber at the bottom of the frame, the sill and the lower corners of each sash. These are the spots where water sits longest and rot almost always starts. Sound timber feels firm and the tool barely marks it. If the screwdriver sinks in easily, the wood feels spongy, or paint flakes away to reveal dark crumbly timber underneath, you have wet rot.
Do this on every window rather than assuming they are all the same. In our experience around St Helier and the coastal parishes, the windows facing the prevailing weather are often far worse than those on the sheltered side of the same house, which changes the sums considerably.
Localised rot, rattling sashes, broken cords, stiff opening and draughts are all fixable. A joiner can splice in new timber where a sill or lower rail has gone, replace sash cords and beads, and fit brush seals that cut draughts dramatically. Done properly with well seasoned timber and modern resin repairs, a spliced section will outlast much of the softwood used in new joinery.
As a rough guide, overhauling and draughtproofing a traditional sash window typically costs a few hundred pounds, and a splice repair to a rotten sill somewhere in the region of £150 to £400 depending on access and how far the rot has spread. Compare that with £1,500 to £3,000 or more for a decent new timber window, fitted and decorated, and repair usually wins where the damage is limited.
Replacement makes sense when rot has spread into the joints or the main frame, when previous botched repairs have left little original timber to work with, or when more than roughly a third of the window is affected. At that point you are paying repair prices for a replacement amount of work, and a new window becomes better value.
It is also worth considering if the windows are cheap post war softwood with no character to preserve, or if single glazing genuinely troubles you. New timber windows with slim double glazing perform far better thermally, though secondary glazing behind a repaired original is a strong middle option and often the only route in protected buildings.
Many houses in St Helier and across the Island sit within conservation areas or are on the List of Protected Buildings, and changing windows on a listed property or a prominent elevation can need planning permission from the Government of Jersey. Repairing on a like for like basis rarely does, which is another point in favour of repair for older granite and Victorian properties.
Whatever you choose, maintenance decides how long it lasts. Salt laden air breaks down paint faster here than inland UK, so budget for repainting exposed elevations every five to eight years and check putty and sills each spring. A well kept timber window can genuinely last a century.
If rot is limited to the sill or the bottom rail of a sash, it can almost always be spliced. Once it has travelled into the corner joints or up the main frame members, or affects more than about a third of the window, replacement is usually better value.
Not if the overhaul includes draughtproofing. Brush seals routed into the sashes and beads typically cut draughts and rattles dramatically, and paired with heavy curtains or secondary glazing the difference in comfort is significant.
Often yes on listed buildings and sometimes in conservation areas or on prominent elevations, so check with the Government of Jersey planning department before ordering anything. Like for like repairs generally do not need consent, which is one reason we often recommend them for older properties.