These timber sash windows embrace the all style and function of traditional box sash windows, yet are enhanced with modern construction and materials. Smooth-running and robust, they feature a classic weight-and-pulley mechanism.

Suitable for non-listed buildings and contemporary developments, our sash windows come in a selection of hardwood and softwood frame finishes, plus RAL colours, to provide freedom of design.

With the option of safety glass, obscured glass, acoustic glass or solar control glass, our wooden double-glazed sash windows can be tailored for every situation.

These box sash windows offer impressive technical performance too, demonstrated by wind load testing, water permeability and air tightness test results.

For heritage sash windows for historic and listed buildings, please browse our heritage windows and doors section.


Product guidance - As Standard
Frame 100 x 160 mm (lining width x frame depth), manufactured using mortise andtenon joints, glued and mechanically fixed.
Sash 39 x 55 mm top rail and stiles, 90 x 55 mm bottom rail, 45 x 55 mm meeting rail.
Mullion / transom 200 mm wide (130 mm for triple sash with fixed outer sash).
Sill projection 35 mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm
Staff / parting beads Timber.
Wood moisture content 12-19%.
Glazing beads Internaly beaded.
Product specification
Material Frame+Sashes Engineered redwood, Bottom Cill in Solid Hardwood - Standard. Engineered hardwood, Accoya, European oak.
Finish Three coat spray applied factory finish using water based micro-porous paint/ stain.
Colour White - RAL 9016 - Standard. Any RAL - from RAL classic range. Stain - from TRC stain range.
Glazing Double glazed, 4/16/4 Low-E top sash – 4toughened/16/4 toughened bottom sash - Standard, Ug-value: 1.1 W/m²K; g-value: 0.52;
U-value 1.5 W/m²K - double glazed.
Perimeter spacer bars White warm edge perimeter spacer with white warm edge integral spacers - Standard. Silver and Black spacer optional.
Frame profile moulding Ovolo 1, Ovolo 2, Lambs Tongue.
Trickle ventilation Concealed through frame head trickle ventilator. EA 1700, 4400, 5000 mm²
Child restrictor Angel lock standard. Traditional Sash Stop optional.
CAD Drawings
Traditional Box Sash Windows
  • Download Brochure
  • Drawings
  • Contact