The Difference Between a Box Sash Window and a Spring Balanced Sash Window

Effortless, elegant, and timeless. Nothing compares to the renowned beauty of a Sash window. As we begin to see an increase in demand for eco-friendly, long-lasting timber doors and windows, homeowners are tempted by the timeless beauty of the sash window.

A box sash window and a spring sash window both combine equal parts form and function, to create the perfect window. Made up of two sashes, one positioned in front of the other, they slide gracefully up or down to open. Held in place by internally moulded staff beads – a detailed trim that frame your sashes. Both are classically detailed and high performing, but there are several defining differences between the two.

What Is The Difference Between a Box Sash Window and a Spring Balanced Sash Window?

A box sash window, sometimes referred to as a ‘sash and case’ window, is a traditional sash window style. One of the key characteristics is the ‘box’ or ‘case’ that houses nylon cords, pulleys, and weights to counterbalance the sashes top and bottom, providing a smooth, effortless motion when opening. This box is discreetly built into either side of the window to maintain the visual elegance of a sash window. These windows retain a classic heritage style while still benefiting from exceptional security, thermal and acoustic performance.

Unlike a box sash window, spring balanced sash windows do not use a traditional weight system, rather the mechanism for opening is spring-loaded. A spiral-shaped rod is hidden inside the frame and connects to a spring that can be adjusted to the weight of the sash. For this reason, they are often used in new-build properties and are a modern-day alternative to classic box sash windows. Having no need for ‘boxes’ or ‘cases’, visually they have a flush reveal for a contemporary edge.

Choosing Between Box Sash Windows or Spring Sash Windows?

Whether or not you opt for traditional timber box sash windows or spring sash windows, both styles of sash windows are sure to bring a unique look to any property, with their classic beauty and traditional sightlines. Ideal for renovating older homes in conservation areas or upgrading a listed building, but in recent years the demand for beautiful timber sash windows has grown and are increasingly being used for many new build projects.

Box sash windows are traditional and offer authenticity, which is particularly important for period property renovations. However, the more complex mechanism means that the box sash window has to include a casing on either side and can therefore cost more to manufacture. In addition, cords can become worn over time, and they may require replacing when they become harder to open, for this reason, they tend to be viewed as the higher-maintenance style.

Spring balanced sash windows are the simpler mechanism of the two and therefore have no visible boxes on either side of the sashes often making them the more cost-effective method. They also benefit from a more lightweight, effortless opening sensation. However, as the more modern style of the two, they may not suit older period properties as perfectly as the traditional box sash window.