A building panel structure is disclosed, in which building panels are used to form a structure. The building panel includes a core and a coating covering a portion of the core. In some embodiments the core consists of a frame and one or more than one insulating structural block. The insulating structural blocks can be encapsulated polystyrene (EPS) foam blocks. In some embodiments the coating includes an inner scratch layer and an outer main brown layer. The inner scratch layer can be formed of at least two layers and a fiberglass mesh. The outer main brown layer can include a fiberglass mesh embedded into the outer main brown layer. A coating/frame coupler is disclosed which securely couples the coating to the frame so that the building panel remains strong and stable even if the EPS foam blocks are melted or damaged in extreme conditions such as a fire.