Spring balance sash
Spring balance sash windows, for openings a box sash cannot fit.
The look of a sliding timber sash, built without weight boxes.
How the construction differs
A traditional box sash uses cast weights on cords running over pulleys, housed in hollow box linings that sit behind the brick reveal, so the frame is wider than the opening. A spring balance sash replaces the weights and boxes with spiral springs inside a slimmer frame that fits within the opening itself.
When a spring balance sash is the answer
Openings with no recess behind the reveal, openings too small for a box frame, openings originally built for casements, and extensions or newer walls.
Frequently asked questions
What is the difference between a spring balance sash and a traditional box sash?
Both slide vertically and look the same from the street. A traditional box sash is balanced by weights on cords in hollow boxes either side of the frame; a spring balance sash uses spiral springs concealed in a slimmer, solid frame.
Why can't I just fit a traditional box sash?
A box frame is wider than the visible opening, because its weight boxes sit behind the brick reveal. If the opening has no recess behind the reveal, or is too small, the box frame will not fit or leaves very little glass.
How do I know which type my opening needs?
We decide at survey, checking the reveal, wall depth and opening size.
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