A cross-ridged roof is a roof with 2 or more ridgelines which either intersect completely or form a T-shaped intersection. The ridges may terminate in gables, hipped roof sections, or other forms. One ridge may be substantially lower than the other as long as the wing covered by the lower-ridged roof spans the entire width of the structure at some point (otherwise it would simply produce dormers, which do not affect the roof form).

Cross-ridged roofs do not apply to roofs in which a single ridgeline bends or curves, regardless of the angle of bend; there must be an actual intersection or fork between multiple ridgelines.

A lower crossing ridge can qualify when the wing beneath it spans the building's full width at some point. A smaller projection that only forms a dormer does not establish the crossing roof form.