Box sash windows are one of the more traditional options for timber sash windows. Their elegance and authenticity have also made them a super popular option for owners of period properties.
The Box Sash window design is characterised by the sliding sashes, that move up and down to open and close the window. This is the same as a Sliding Sash window, however, because what makes the Box Sash different is all in the mechanics.
Mechanically, the Box Sash vertical window box houses a system of ropes and a pulleys on a piece of sash cord which provides effortless lifting of the sashes, even with larger, heavier windows. This is all built into the side of each of the windows, sp that it can’t be seen and the windows appearance doesn’t change.
This is the traditional way of building a Sash window, which is where the authenticity and likeness to the original windows comes in.
The newer alternative way of building a Sliding Sash window is with the use of Spiral balances, which uses springs instead, which is overall less complicated than weights and pulleys.