Spring sash windows offer a cost-effective alternative to traditional box sash designs. They deliver classic style, but incorporate a simpler, more compact and modern spring balance mechanism in place of weights and pulleys.

In other respects, spring balanced sash windows display all the benefits of our traditional timber sashes, with unrivalled quality, design and engineering.

Double-glazed as standard, they are available with safety glass, obscured glass, acoustic glass or solar control glass. Triple glazing is also available for larger contracts. Twin gasketing ensures reliable weather containment.

These spring sash windows are well chosen for mid-range new developments, as well as replacing classic windows on non-listed buildings. (For historic and listed buildings, we recommend you browse our heritage windows and doors.)


Product guidance - As Standard
Frame 55 x 160 mm (lining width x frame depth), manufactured using mortise and tenon 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 110 mm wide (70 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 Internally 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 1, Lambs Tongue 2.
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 Spring Sash Windows
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