Anatomy of a Scottish Sash Window

A traditional sash and case window consists of a fixed outer case and movable glazed sashes. The sash stiles and rails surround the glass, while glazing bars divide smaller panes.

Understanding the details

The box case commonly houses cords, pulleys and counterweights. Staff beads and parting beads guide the sashes; the sill sheds water away from the building fabric.

What to look for

Identify each part before diagnosing a fault: a sticking sash may involve paint, alignment, swollen timber or a failed balance system.

The fixed case

The case is secured within the masonry opening. Its pulley stiles contain channels and weight pockets; the head and sill complete the frame. A sloping sill and sound external joints help direct rainwater away from vulnerable timber.

The moving sashes

Each sash is formed by vertical stiles and horizontal rails. The meeting rails meet when closed, while glazing bars divide individual panes. Staff beads retain the inner sash; parting beads separate the sliding paths.

Diagnosing faults by component

A dropped sash may indicate a failed cord or unsuitable counterweight; sticking can result from accumulated paint, distorted timber or swollen beads. Identify the cause before removing historic material.

Related archive guides

Continue with our window anatomy guide, technical glossary and research resources. This educational material is general guidance, not a substitute for a property-specific conservation assessment.