The disclosure provides a method that includes providing or assembling a rectangular horizontal member, joining a vertical member to the rectangular horizontal member such that the vertical member bisects a length of the horizontal member and forms a T-junction at the horizontal member, joining first and second sloped members to the rectangular horizontal member and vertical member such that the first and second sloped members span from a top of the vertical member to opposing ends of the horizontal member, and joining first and second support members such that the first and second support members span from the T-junction between the vertical member and horizontal member to work points on an underside of each of the first and second sloped members. The structure thus formed can be assembled from prefabricated units shipped together in parallel planar orientation in a shipping container to provide a roof truss unit.