Renovating Sash Windows

There are an estimated 40 million Box Sash windows installed in the British Isles. Most of them do not work well, even though the wood is still in reasonable condition. Many suffer from broken sash cords or rusted pulleys, rattle in the wind, let through drafts or are so over painted they cannot be properly opened or closed. The first reaction is to recommend replacing them with modern equivalents.


Prices will vary based on the extent of the damage:

  • For a recondition and new draught seals (this may not include stripping, priming and painting) = £250 per sash
  • Box sash window replacement = £1,200
  • Double-glazed sash replacements only, to fit into existing frames = £500 per sash

Think again! Refurbishment to today’s standard is not difficult. All the parts you need to ensure smooth action, draught proofing, and eliminating rattles, together with securing your sash or casement windows are available to purchase from Reddiseals.

Timber Beading

Reddiseals are the largest independent supplier of timber window components and accessories in the UK and have been successfully supplying the joinery industry since 1989. Reddiseals specialise in sash window components offering solutions for the restoration and renovation of traditional box sash windows, together with spiral balances and associated furniture. Reddiseals also provide a comprehensive range of products suited to timber casement windows. With an extensive choice in products, style and finish, Reddiseals offer the best range, quality and value for money in the market.

Remember the greatest energy saving comes from eliminating draughts. All our staff beads and parting beads have draught seals pre inserted or seal channels to insert your own. Replacing single glass with sealed units in old sashes where appropriate, will undoubtedly enhance the window’s performance. Double glazed sealed units should always be recommended where possible if new sashes have to be made or where new Box Sash windows are being installed. If your property falls into a conservation area then refurbishing existing sash windows may be more preferable as no planning permission is required. There are sash refurbishment specialists available that would be happy to give a no obligation quotation for any work undertaken.

Windows are the eyes of a period building. These, combined with other external features, add to the overall look. Here are some key tips to help your windows stay in keeping with your period property.


  • Do your research if you want to stay in keeping with your period property
  • Do regularly paint or weather treat original wooden windows
  • Will reduce energy bills, the majority of heat is lost through poorly draught proofed windows and doors
  • Do retain key features and proportions where possible, they are an integral part of the properties character


  • Windows are the eyes of a period building and of all the external features matters. Do not replace original windows for PVC, repair and restore
  • Repairing and restoring original sash windows does not require planning permission or building regulations approval.
  • Ignore the instructions, should you require further assistance please contact us to speak to our technical department

Still struggling? Then watch our restore and renovation video here:

Thanks to Heritage Sash Window Specialists team for showing our products off to their best.