Abstract: Jointing element for a compoundable unit structure, comprising a plurality of pegs extending along axes which intersect perpendicularly at one point, the pegs being joined together in proximity to the point of intersection of the axes and having their ends dimensioned such that they may be inserted into support tubes; and a plurality of seats in the intersection and joining region of the pegs arranged to accommodate the corners of panels disposed substantially coplanar to the planes defined by the axes, the seats being dimensioned such that the edges of the panels come into direct contact with the support tubes.