Abstract: A prefabricated panel building system, including a plurality of wall panels adapted to be joined together; a structural frame defining the shape and configuration of a building; the frame having horizontal tracks wherein the panels are adapted to be slid against each other; each panel including specially adapted interlocking edge members having complementary profiles configured to interlock to form integrated stud or cross members, wherein the arrangement confers substantial rigidity and integrity. A method of building using the panels of the system.