Ausfachung

Ausfachung is a German term meaning the infilling or filling in of a hollow, cavity, or space with a material. The word derives from aus- (out, from) and Fach (compartment, panel) and is used in several disciplines to describe how a void is closed or a feature is sealed by an infill.

In timber-framed architecture (Fachwerk), Ausfachung refers to the infill panels placed between the structural timbers. Traditional infills include bricks, fired clay blocks, or wattle-and-daub plaster; later infills used plaster, render, or lightweight materials. The infill determines both the wall’s appearance and its thermal performance, and regional Fachwerk styles show characteristic patterns of infill.

In geology and archaeology, Ausfachung is the general term for the filling of cavities or voids within rocks, soils, or archaeological deposits by sediments, minerals, or other materials. Natural infilling can occur through sediment deposition or mineral precipitation; human activities can also create or seal infilled features, such as backfilled excavations.

Understanding Ausfachung is important for the conservation of historic buildings, the interpretation of geological sequences, and the assessment of archaeological contexts, because the choice and composition of infill influence durability, dating, and stratigraphic integrity.