A ladder window is a tall (portrait format) window in which the glazing bars are arranged so that the effect recalls the rungs of a ladder: a series of narrow horizontal panes stacked one above the other. The window is therefore taller than it is wide, with a strongly horizontal subdivision. The Dutch term is laddervenster or ladderkozijn.
The type is closely bound up with the Amsterdam School (roughly 1910 to 1930), where it was widely used as an expressive façade motif. The horizontal counterpart — a wide, low window with a comparable subdivision — is called a band window.
How to recognise it
- Portrait proportion — distinctly taller than wide
- Only or mainly horizontal glazing bars — no vertical subdivision, or only a subordinate one
- Equal or rhythmically diminishing pane heights — the rhythm is the essence of the motif
- Often in series — several ladder windows side by side, giving the façade a strong grid
Use and practical implications
The ladder window is a stylistic motif rather than a structural component. Even so the form has consequences for the work:
- Many bars means a lot of timber in the opening — the daylight admitted is less than the size of the opening suggests
- Maintenance intensive — every bar has two sealant lines or beads; on timber bars this is where wood rot starts. Check the horizontal top faces in particular, where water stands
- Insulating glazing — true through glazing bars with insulating glass make every pane a separate unit, which is expensive. In refurbishment a thin insulating unit per pane is often chosen, or applied bars with a spacer bar within the cavity
- Listed buildings — where a building is listed, the window pattern is part of what is protected, and replacement with a flat sash and stick-on bars is generally not permitted without consent
Related terms
- Glazing bar
- Band window
- Amsterdam School
- Window frame
- Insulating glazing
- Wood rot
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