Abstract: A trailer van construction with side walls which provide the trailer van with greater storage space. The trailer van includes a floor, upstanding end walls, a roof and opposite side walls. Each side wall includes a generally rectangular, elongate panel having generally parallel upper and lower edges, and a top framing structure. The framing structure includes a top rail having a depending plate portion and at least one laterally extending flange for supporting the roof. The end walls have different heights and the plate portion has a vertical dimension greater than the difference in height between the end walls. A capping member is assembled over the upper edge of the panel and secured to the outer surface of the plate portion along a line which is nonparallel to the top edge of the top rail such that the upper margin of each side wall is defined by a wedge-shaped section of the plate portion.