Sliding Sash windows
Spring sash inside viewSpring sash outside view

Sliding sash windows are traditional, time proven windows, widely used in the UK. Their design is unique because, unlike windows of any other style, they have two vertically sliding sashes. There are two different types of sash windows, depending on the mechanism employed to assist to raise the sashes.

We manufacture both spring sash and box sash windows. Our products combine old traditions with modern technology in both the design and the production process.

Spring sash windows

The mechanism employed to raise the sashes in spring sash windows is special spring balances. This is more modern and cheaper alternative to weight, string and pulley system used in box sash windows. In addition to this, spring balanced sash windows have a benefit of larger aperture compared with traditional box sash of equal total area. It means that a spring sash of equal total area always has larger glass units installed, than equivalent box sash, due to slimmer frame. This type of windows exceptionally well combines both traditional ellegance of british style with contemporary technology.

Box sash windows

Box sash windows use traditional mechanism, consisting of lead weights, pulleys and strings, assisting to open the window. This type of window is the most authentic as it looks the same as box sashes made ceturies ago. Only materials are modern.

Detail description
  • Glass unit: one chamber, double glazed, thickness 20 mm, 4-12Ar-4, warm edge, single low-e pane.
  • Possibility to choose glass units with tempered, laminated, low-e or tinted glass panes for extra safety, thermal eficiency, sound isolation and looks.

  • Fully droughtproof:
  • Windows are fully sealed and drought proof. Side "Flexislide" seals ensure extra insulation and do not allow the window to rattle in the wind.

  • Decorative horns on upper sash.
  • "Caldwell" ironmongery as standard.
  • Window frames are painted in any RAL colour. Paint used is 'Teknos' which is tested under severe Nordic climate conditions.
  • Many different variants of Georgian bar placement.
  • Hardwood sill as standard.
  • Many other possible choices:
  • sill extension, lockable sash fastener, sash stops limiting sash opening, arched head, arched box and upper sash fillings, night vents etc..

Technical documentation

Spring sash window cross section drawings

Box sash window cross section drawings