Characteristics Of Casement Windows

Casement windows are typically characterised by a window with one or more hinges, attached to a frame. Before the advent of sash windows, they were the most common type of windows used in households. Casements were once the most widely purchased style of windows, before sash windows became commonplace. They traditionally consisted of framed glass panes that were fixed in place by strips of lead and the window could be opened outwards.

Useful Properties

Whole Opening

Casements can be opened much further than any other type, since the entire window can be swung open. This can be compared to the following types of windows.

Double-hung style: the whole window cannot be opened only the upper or lower half can be open at any one time.

Sliding: only one side of the window can be opened with this type of window.

Fixed: these windows cannot be opened at all.

Casement windows are a popular choice, especially if the size of the window opening is important.

Harder for Break-ins/More difficult for Break-ins

Casement windows feature a hook shaped, embedded casement lock which is very inaccessible to someone outside and thus makes the window very difficult to break into.

In comparison the double-hung style of window can be opened quite easily by lifting the sash using a long object such as a pry bar.

Maximum Ventilation

The fact that the entire window can be opened allows for maximum ventilation. Furthermore, wind which blows sideways along the property wall will find it difficult to penetrate, thus creating a lack of ventilation. Since casements have an opening sash they can essentially direct the wind into the house which can be especially useful if you have any windows directly facing another building with very little space in between.

Opening & Closing

Casements are easy to open and close due to their single leaver or tandem latches, and they can even be enhanced by fitting automatic openers.



The large window opening can be dangerous at high levels, since the gap is typically sufficient for small person or child to crawl out of and therefore poses a risk for families with young children.

Incompatibility with Air Conditioning

Casements typically do not cater well for air-conditioning units since they open outwards, especially when compared to other types such as sliding windows.

Size Limitations

Casements are designed to open outwards which means the opening needs to be strong enough to support the window. This places limits on how large a casement can be without placing unnecessary strain on the window opening.