Abstract: A building structure requiring virtually no fasteners for its assembly, composed generally of a plurality of mutually interlocking floor panels which rest upon a plurality of floor stringers, a plurality of uprights interlocked with respect to the floor panels, a plurality of wall panels interlocked with respect to the uprights, a header rail on each left and right wall of the building structure fastened to adjoining uprights and interlocked with adjoining sidewall panels, a plurality of mutually interlocked roof trusses which are fastened to the header rails, and a plurality of roof panels interlocked with the roof trusses and adjoining rail header. The aforesaid interlocking relationships are provided by a male-female structural interrelationship between adjoining interlocking components. The building structure according to the present invention is further preferably provided with a self-leveling feature which connects with the floor stringers and floor panels.