A variant of the standard casement window is the French casement. This window provides a large opening with no vertical element to split the opening when the window is open. A French casement allows the design to have a visually consistent casement size throughout the project while also ensuring that the window opening meets the minimum standards of the building code.
Cost. Expect to pay more for a casement when compared to a double-hung. This is because of the mechanical operation and subsequent hardware requirements. Of course, the tighter seal caused by the mechanical operation will make a casement window more energy efficient than a double hung or slider/glider. And, while some will argue this point, a casement window with a multi-point locking system will generally be harder to break through, making the house more secure.
An awning window is much like a casement window in that it’s mechanically operated with a crank. Unlike the side-hinged casement, an awning window is hinged at the top so that the sash pivots in lieu of swinging.
When to use them. An awning window shares many of the design considerations of a casement: The style is suited to both traditional and contemporary designs, the sash and glass are all in one plane, the screen is located at the interior and the hardware is an important design element. Unlike the casement, though, an awning window can be open when it’s raining. Because an awning pivots up and out, the sash effectively creates a mini awning that prevents the rain from coming through the window opening.
However, unless quite large, an awning window will be a problem when certain building code requirements are factored. So check with an architect before using an awning in a room where windows must have clear opening minimums.