A recreational vehicle has a floor and a vehicle body with a pair of walls, a roof, and end shells disposed at the front and rear ends of the walls and roof. Each wall has a plurality of horizontal members each extending at least part way between the front and back end of the respective wall and a plurality of spaced apart vertical bows each extending at least part way between the bottom and top of the respective wall. Each of the vertical bows has an inner surface and an outer surface with a recess defined in the inner or outer surface, the recess configured to receive one of the plurality of horizontal members therein such that the horizontal member does not extend beyond a portion of the inner or outer surface adjacent the recess. An outer wall skin is attached to the outer surface of the bows or members.