A hopper window (Dutch “kiepraam”) is a window hinged at the bottom whose top edge tilts inward. This creates a narrow opening at the top of the window, allowing air in while keeping most rain out and avoiding a draught at eye level. It is a commonly used ventilation position.
How it works
- The hinges are at the bottom, with a stay or scissor arm at the top that limits the tilt
- The window falls inward at a small angle
- The opening is high, so the incoming air moves upward into the room
Application
- Ventilation in bathrooms, kitchens, bedrooms and toilets
- Cellars and storerooms — a small hopper window for air exchange
- Part of a tilt-and-turn window — which combines an ordinary turn action with a tilt action in one window
Points to note
- A hopper window on the ground floor stands ajar: vulnerable from a security point of view. Consider a window restrictor or lockable hardware
- Make sure the stay firmly limits the tilt position, otherwise the wind can damage the window
- Cleaning the outside is harder with a hopper window than with a side-hung casement
Related terms
- Window
- Casement window
- Tilt-and-turn window
- Window frame
- Fanlight
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