If your original sash boxes are in a suitable condition to retain, SashWise can manufacture bespoke double glazed timber sashes to fit within the existing box frames. This allows you to upgrade ageing or single glazed sash windows without replacing the complete window.
The new sashes are carefully designed to replicate the style, pane configuration, mouldings and traditional details of the originals, helping preserve the architectural character of the property while improving thermal performance, draught proofing, security and sound insulation.
Manufactured in the UK at our dedicated workshop, each set of sashes is made specifically for the existing window and fitted as part of a wider restoration of the retained sash boxes.
New double glazed timber sashes may be suitable if:
Your existing sash windows are single glazed and you want to improve thermal performance.
You want better protection from external noise.
Your existing sashes are worn or deteriorated but the original sash boxes can still be retained.
You want the benefits of double glazing without replacing the complete sash window.
Preserving the traditional proportions and character of the existing windows is important to you.
Retaining the existing sash boxes can make the upgrade less disruptive and more cost effective than replacing the complete window.
Double glazed sashes improve thermal performance and help reduce heat loss through the glazing.
Appropriate glazing specifications can also improve sound insulation from outside.
New sashes are made to replicate the proportions, pane configuration, horns and moulding details of the originals wherever possible.
The retained sash boxes are restored and the completed windows incorporate draught proofing, helping improve comfort and operation as part of the same project.
Your new timber sashes are manufactured from Sapele or Accoya in our workshop, with the design based on the existing windows. We take care to replicate the original style, pane configuration, sash horns and moulding details so that the finished window remains sympathetic to the property.
On site, the retained sash boxes are stripped back to the original wood and any rot repairs are carried out. Should the timber sills be beyond repair, new Accoya sills can be fitted within the original boxes. The boxes are then fully painted throughout.
Once the sash boxes are ready, new pulleys and lead weights are installed as required and the new double glazed sashes are hung using the traditional weighted sash system. A specialist draught-proofing system is incorporated to help reduce draughts and improve the operation of the window.
The installation is completed with suitable security locks and sash furniture.
The glazing specification is selected according to the dimensions of the retained sash box and the requirements of the property. In many cases a slim restoration double glazed unit can be used where the available depth is restricted. See our Timber Window Glazing Options for the wider range available.
Because the original sash box is retained, the available glazing depth varies from property to property. During the survey we assess the existing box and sash dimensions before recommending the most appropriate glazing specification.
Where depth is limited, a slimline heritage or restoration double glazed unit may allow modern glazing to be incorporated while retaining the proportions of a traditional sash. Other glazing options, including vacuum glass, acoustic and specialist glass, can be considered where the existing window construction allows.
All new timber sashes are finished with appropriate sash furniture and installed alongside our draught-proofing system, creating a complete upgrade rather than simply replacing the glass.
Please call us on 0208 977 4627 or complete the form below.
We're always happy to discuss your timber window and door needs. Whether you're looking for advice, a detailed quote, or simply want more information about our services, our friendly team is here to help.
