A soffit is an exterior or interior architectural feature, generally the horizontal, aloft underside of any construction element. Its archetypal form, sometimes incorporating or implying the projection of beams, is the underside of

eaves The eaves are the edges of the roof which overhang the face of a wall and, normally, project beyond the side of a building. The eaves form an overhang to throw water clear of the walls and may be highly decorated as part of an architectural sty ...

(to connect a retaining wall to projecting edge(s) of the

roof A roof ( : roofs or rooves) is the top covering of a building, including all materials and constructions necessary to support it on the walls of the building or on uprights, providing protection against rain, snow, sunlight, extremes of temp ...

). The vertical band at the edge of the roof is called a

fascia A fascia (; plural fasciae or fascias; adjective fascial; from Latin: "band") is a band or sheet of connective tissue, primarily collagen, beneath the skin that attaches to, stabilizes, encloses, and separates muscles and other internal organ ...

Etymology

The term ''soffit'' is from it, soffitto, formed as a ceiling; and directly from ''suffictus'' for ''suffixus'', la, suffigere, to fix underneath).

Soffits in homes and offices

architecture Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing buildings ...

, soffit is the underside (but not base) of any construction element. Examples include:

Under the eaves of a roof

In foremost use ''soffit'' is the first definition in the table above. In spatial analysis, it is one of the two necessary planes of any (3-dimensional) optionally built area,

, which projects, for such area to be within the building's space. In two-dimensional face analysis it is a discrete face almost always parallel with the ground that bridges the gap(s) between a building's siding (walls) and either: their parallel extraneous plane (

) where such exists; or where no such plane, a point along (or the abrupt end of) the roof's outer projection (overhang). Soffits and fascias are archetypally screwed or nailed to rafters known as