Abstract: A method for making a scroll type housing for a centrifugal blower wherein a flat discharge plate is provided with a rectangular discharge opening and a pair of lugs are spaced from each of a first pair of opposing parallel edges of the opening. Narrow upstanding flanges along the edges are spaced slightly from the lugs and the second pair of opposing edges of the opening are each provided with a narrow elongated portion which is offset to a shallow depth in the direction of the flanges. A scroll member is provided in an elongated generally flat flexible sheet of material with a narrow end flange formed integrally along each end edge. The flanges project generally in the same direction and the member also has a reverse bend adjacent one end approximately in the form of a desired final configuration of a "cut-off" section of the housing. Three lanced openings are spaced apart along each side edge of the member.