Prefabricated wall panel

A prefabricated wall panel comprising a central core of insulating material, two substantially parallel facing sheets on the opposite faces of said core, said core having a lateral projection of a thickness less than said core along one side edge of said panel, each of said facing sheets having free edges along said one edge extending in spaced relationship to said lateral projection to define a pair of grooves along said one edge, each of said grooves being defined on its inner side by said lateral projection and on its outer side by the free edge of one of said facing sheets, the opposite side edge of said panel having a connecting member, said connecting member having a pair of outer laterally projecting tongues, the edges of the adjacent facing sheets being bent around said outer projecting tongues, said connecting member also having a pair of inner laterally projecting tongues spaced inwardly of said outer projecting tongues, the space between and inner projecting tongue and an adjacent outer projecting tongue being sufficient to receive the free edge portions of the sheets of an adjacent identical wall panel, the inner laterally projecting tongues being spaced from one another by a distance to receive the lateral projection of the core of an adjacent identical wall panel, and said inner tongues being positioned and dimensioned to be receivable in the grooves of said adjacent panel.