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

Fascia is an architectural term for a vertical frieze or band under a roof edge, or which forms the outer surface of a cornice, visible to an observer. Typically consisting of a wooden board, uPVC or non-corrosive sheet metal.