Casement window
A casement is a window that is attached to its frame by one or more hinges. Casement windows are hinged at the side. They are used singly or in pairs within a common frame, in which case they are hinged on the outside. Casement windows are often held open using a casement stay. Windows hinged at the top are referred to as awning windows, and ones hinged at the bottom are called hoppers.
In the UK, casement windows were common before the sash window was introduced, and usually metal with leaded glass—glass panes held in place with strips of lead (called lead "cames"; leaded glass is not to be confused with lead glass, which refers to the manufacture of the glass itself). These casement windows usually were hinged on the side, and opened inward. By the start of the Victorian era, opening casements and frames were constructed from timber in their entirety. The windows were covered by functional exterior shutters, which opened outward. Variants of casement windows are still the norm in many European countries.
They are opened with a crank, lever, or cam handle, which is placed around hand height or at the bottom and serves as a window lock. A crank, stay, or friction hinge is necessary when the window opens outward, to hold the window in position despite wind.
Often the glass panes are set in a rabbeted frame and sealed with beveled putty or glazing compound to secure the glass.
Casement windows "generally have lower air leakage rates than sliding windows because the sash closes by pressing against the frame."
Casement windows are also excellent for natural ventilation strategies, especially in hot climates. They can be hinged to open outward and angled in order to direct breezes into the building.
Out-swinging shutter, in-swinging window
Danish casement window
Casement window on Crete
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