A building panel formed from sheet material extends in a longitudinal direction along its length and includes a curved center portion in cross section, a pair of side portions extending from the curved center portion, and a pair of connecting portions extending from the side portions. The curved center portion includes a plurality segments extending in the longitudinal direction. The panel is curved in the longitudinal direction without having transverse corrugations. A particular segment may have a depth greater than that of another segment to accommodate the longitudinal curve. A system for longitudinally curving the panel includes first and second curving assemblies, each of which includes multiple rollers arranged to contact the panel as it passes along, a positioning mechanism for changing a relative rotational orientation between the first and second curving assemblies, a drive system for moving the panel longitudinally, and a control system for controlling the positioning mechanism.