A casement window is a
window
A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent materia ...
that is attached to its frame by one or more
hinge
A hinge is a mechanical bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation: all other ...
s 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.
Overview
Throughout Britain and Ireland, casement windows were common before the
sash window
A sash window or hung sash window is made of one or more movable panels, or "sashes". The individual sashes are traditionally paned window (architecture), paned windows, but can now contain an individual sheet (or sheets, in the case of double gla ...
was introduced. They were usually metal with
leaded glass, which refers to glass panes held in place with strips of lead called
came
A came is a divider bar used between small pieces of glass to make a larger glazing panel.
There are two kinds of came: the H-shaped sections that hold two pieces together and the U-shaped sections that are used for the borders. Cames are mostl ...
s (leaded glass should not be confused with
lead glass
Lead glass, commonly called crystal, is a variety of glass in which lead replaces the calcium content of a typical potash glass. Lead glass contains typically 18–40% (by weight) lead(II) oxide (PbO), while modern lead crystal, historically als ...
, 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 sometimes opened with a
crank,
lever
A lever is a simple machine consisting of a beam or rigid rod pivoted at a fixed hinge, or ''fulcrum''. A lever is a rigid body capable of rotating on a point on itself. On the basis of the locations of fulcrum, load and effort, the lever is div ...
, or
cam
Calmodulin (CaM) (an abbreviation for calcium-modulated protein) is a multifunctional intermediate calcium-binding messenger protein expressed in all eukaryotic cells. It is an intracellular target of the secondary messenger Ca2+, and the bind ...
handle
A handle is a part of, or attachment to, an object that allows it to be grasped and manipulated by hand. The design of each type of handle involves substantial ergonomic issues, even where these are dealt with intuitively or by following tra ...
, 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
rabbet
A rabbet (American English) or rebate (British English) is a recess or groove cut into the edge of a piece of machinable material, usually wood. When viewed in cross-section, a rabbet is two-sided and open to the edge or end of the surface in ...
ed frame and sealed with
bevel
A bevelled edge (UK) or beveled edge (US) is an edge of a structure that is not perpendicular to the faces of the piece. The words bevel and chamfer overlap in usage; in general usage they are often interchanged, while in technical usage they ...
ed
putty
Putty is a material with high plasticity, similar in texture to clay or dough, typically used in domestic construction and repair as a sealant or filler. Although some types of putty (typically those using linseed oil) slowly polymerise and be ...
or
glazing compound to secure the glass.
The hinging of casement windows is referred to using the following abbreviations: FCL refers to a left-handed window, where the hinges are located on the left and the locking mechanism is on the right. FCR is a right-handed window with the hinges on the right and the locking mechanism on the left. These definitions apply to a window when looking at it from the exterior ("from curb" or FC). In some countries architectural diagrams of casement windows show a dashed triangle with the hinged side identified by the point of the triangle (e.g. USA), while in others they point to the lever, showing a simplified perspective of the opened window (e.g. Hungary, Germany). Furthermore in some countries (e.g. Hungary, Germany) diagrams also make distinction between windows opening inwards (dashed line) or outwards (solid line). FCL windows feature a triangle pointing to the left; FCR windows have a triangle pointing to the right. Casement windows design also allow for ease of cleaning energy efficiency.
Energy efficiency and natural ventilation
Casement windows, including awning and hopper types, "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
Passive ventilation is the process of supplying air to and removing air from an indoor space without using HVAC, mechanical systems. It refers to the flow of external air to an indoor space as a result of pressure differences arising from natural ...
strategies, especially in hot climates. Casements allow more control of ventilation than flush-opening windows. They can be hinged to open outward and angled in order to direct breezes into the building.
Image:Green window.JPG, Out-swinging shutter, in-swinging window
Image:Danish window.jpg, Danish casement window
Image:Crete window.jpg, Casement window on Crete
Crete ( el, Κρήτη, translit=, Modern: , Ancient: ) is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, and ...
Image:St Malo 04.JPG, St. Malo
Image:Window001b.jpg, Fort Sam Houston
Fort Sam Houston is a U.S. Army post in San Antonio, Texas.
"Fort Sam Houston, TX • About Fort Sam Houston" (overview),
US Army, 2007, webpageSH-Army.
Known colloquially as "Fort Sam," it is named for the U.S. Senator from Texas, U.S. Represen ...
Image:Gordijnen aan venster.JPG, Casement window
Image:View into a garden through an open ground floor window in Germany.jpg, Casement window swinging in
Image:Door handle.jpg, Window locks use lever handles
Notes
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