Knee wall

In architecture, a knee wall is typically a short wall, usually under three feet (one metre) in height. In his book A Visual Dictionary of Architecture, Francis D. K. Ching defines a Knee Wall as "A short wall supporting rafters at some intermediate position along their length." The term is derived from the association with the vertical location of the human knee. Knee walls are common in old houses that are typically not a full two storeys in height, in which the ceiling on the second floor (in the "attic" area) slopes down on one or more sides. These houses are sometimes referred to as one-and-a-half storeys.

It is also commonly known as a half-wall, buttress or partial-wall.