A pillar to rocker joint assembly comprising a tubular pillar having a pinched flange near a lower end of the pillar is joined to a rocker assembly including a side sill and rocker reinforcement. A method of making a pillar to rocker joint assembly that comprises a vehicle structural support is formed by welding a structural support pillar to an outer body panel through an access opening in the pillar and welding a rocker reinforcement to a side sill. The rocker reinforcement is welded to the pillar through an access opening in the side sill, an access hole in the body outer panel, and an access opening in the pillar that is vertically spaced relative to the first access opening. A bottom flange of the B-pillar is welded to a lower edge flange of the rocker reinforcement and a lower edge flange of the side sill.