Our sliding sash windows have been developed based on traditional Georgian and Victorian design aesthetics

Built using modern manufacturing techniques, they windows display classical lines and features.

Typically sitting behind brickwork, stone or a rendered reveals Box Sash Windows normally have a 1” margin showing of the box externally. They can also be positioned towards the face of a property and neatly finished with a decorative architrave.

Our box sashes are lead weighted, hung on sash cord with pulleys and are fully draught stripped. You'll enjoy years of easy operation and great service from them.

Here at Redwood Joinery we produce two styles of Box Sash Windows:

The Modern Box Sash Window

  • Modern properties can have standard or acoustic Planitherm, argon filled double glazed units with warm edge spacer bars
  • Slim glazing bars, secret trickle ventilation with safety restrictors or security stops
  • Matching sash horns
  • Moulding profiles available are lambs tongue, ovolo and splay

The Conservation Traditional Box Sash Window

  • Grade 1 and 2 listed building and properties within a conservation area can achieve fine solid glazing bars with individual panes of glass
  • We offer ovolo, lamb's tongue and a fine heritage lamb's tongue profiles
  • Matching sash horns
  • Glass ranging from single 4mm float, 6.4mm laminated and slim double glazed conservation units 10mm to 12mm thick, argon or krypton filled
  • Hand draw and reproduction crown glass is available on request
  • All putty glazed in our workshop

As a modern alternative to Box Sash Windows we offer a cost-effective and slimmer profile Spring Balanced Window. This also works well when no or little reveal is available. The spring balance mechanism counterbalances the sashes as opposed to traditional cords and weights, so it does not have a box on either side. This allows for a smaller section. The absence of boxes also means this type of window can replicate a narrow mullion, typically found in original double glazed windows.


When it comes to ironmongery we offer a standard range and a superior range. We use suppliers such as Croft, Frank Allart and Samuel Heath and a wide range of finishes are available. The hook fastener is a favourite of ours for its elegant look and simplicity.

Please contact us with your Sash Windows enquiry where we can match your existing details or produce a bespoke product for your home.